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4. Liquid rotary jet fragmentation of a pressure atomizer

Author

Bruno Molle, Séverine Tomas, Catherine Gibert, Fabien Anselmet, Alix Bartoli, Muriel Amielh, Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), AUTRES, Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
Momentum flux, Primary atomization, Jet (fluid), Materials science, Drop size, Fragmentation (computing), Rotary jet, Mechanics, Shadowgraphy, Rotation, 6. Clean water, Bag breakup, Aerodynamic force, Atmosphere, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Physics::Atmospheric and Oceanic Physics
Abstract

International audience; Rotary water jets are commonly used in the world of agriculture, particularly in irrigation and in treatment with pesticides in the form of micro-sprinklers. However, their study is not very well developed, even though the problems linked to water resource losses or the drift of pesticides in the atmosphere are well known. Controlling the size distribution of the drops that are generated becomes essential to avoid these problems. The observation of the fragmentation of a rotating jet is implemented in this study. The shadowgraphy method coupled with a drop size and velocity detection algorithm has been adapted for this rotating system. Different modes of rupture can be observed and drop size distributions are analyzed. Primary atomization is controlled by the orthoradial air velocity generated by the rotation and by the stretching of the ligaments due to the Coriolis and centrifugal forces. We compare the different modes of fragmentation as a function of the aerodynamic forces created by the rotation and the momentum flux of the water jet in the air.

Published
2021

5. Probability density functions for fluctuations in turbulent two-phase flames

Author

Fabien Anselmet, R. Borghi, Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Fluid Flow and Transfer Processes, Physics, Modeling of droplets vaporization-condensation, Basis (linear algebra), Turbulence, Mechanical Engineering, Computational Mechanics, Probability density function, Mechanics, Condensed Matter Physics, 01 natural sciences, 010305 fluids & plasmas, Micromixing, Turbulent spray flames, Eulerian-Lagrangian models, Physics::Fluid Dynamics, JPDF for chemical species, Mechanics of Materials, Phase (matter), 0103 physical sciences, Vaporization, Piecewise, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Diffusion (business), 010306 general physics
Abstract

International audience; Probability density function methods for characterizing various fluctuating quantities in the reacting gas phase of turbulent spray flames are presented, for the development of which E.E. O'Brien has been a pioneer. Balance equations for two-phase flows considered as a piecewise continuous medium are first presented, with the interface conditions containing the vaporization-condensation equilibrium. From these, the equation for the joint probability density function of temperature and composition in the gas phase is derived, in which specific terms related to vaporization are identified. The terms needing modeling are then highlighted. The first one is the classical micromixing term, which has to include all the features already discussed for single phase reacting flows, but adaptation to two phase flow has to be questioned. And, mainly, several unclosed terms are dealing with vaporization, needing a specific attention. It is shown that proposals for their modeling can be obtained on the same bases as in the socalled Eulerian-Lagrangian models, which will directly induce changes of the shape of the probability density function. We finally discuss the model presented herein and comment its connection with recently published literature for this subject. Specific attention is devoted to the combustion regimes and to the presence of diffusion flamelets surrounding fuel droplets or groups of droplets. The proposals presented here go one step further compared to the recent studies, and they have now to be compared with well defined experiments, numerical experiments with direct numerical simulations or real experiments in conveniently controlled conditions.

Published
2021

6. Multimodal distributions of agricultural-like sprays: A statistical analysis of drop population from a pressure-atomized spray

Author

Romain Vallon, Malek Abid, Fabien Anselmet, Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Fluid Flow and Transfer Processes, education.field_of_study, Materials science, Turbulence, Drop (liquid), Population, Nozzle, Computational Mechanics, Mechanics, [PHYS.MECA]Physics [physics]/Mechanics [physics], Velocimetry, Combustion, Tracking (particle physics), 01 natural sciences, 010305 fluids & plasmas, Physics::Fluid Dynamics, [SPI]Engineering Sciences [physics], Joint probability distribution, Modeling and Simulation, 0103 physical sciences, Physics::Atomic and Molecular Clusters, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], 010306 general physics, education, ComputingMilieux_MISCELLANEOUS
Abstract

International audience; This paper focuses on the statistical analysis of a droplet population produced by a pressure-atomized jet spray, laying in the second-wind-induced regime, far behind the nozzle. The droplet size and axial velocity derived from droplet tracking velocimetry measurements are shown to follow bimodal distributions and their modeling is tackled in the framework of turbulence and of combustion applications, respectively. In addition, the existence of subsets of droplets showing specific behaviors is brought to light from the analysis of the experimental droplet-size–velocity joint probability distribution function (PDF). Such subsets can be precisely defined using the properties of the size and axial-velocity distributions. Finally, the trend of the joint PDF is depicted due to a quadratic relationship which is derived in the context of combustion and shown to work here as well, far behind the nozzle.

Published
2021

7. Experimental and numerical characterization of the vortex zones along a labyrinth milli-channel used in drip irrigation

Author

Jafar Al-Muhammad, Muriel Amielh, Nassim Ait-Mouheb, Fabien Anselmet, Séverine Tomas, Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), European Project: 311933,EC:FP7:KBBE,FP7-KBBE-2012-6-singlestage,WATER4CROPS(2012), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD)

Subjects
Flow (psychology), Labyrinth micro-channel, Drippers, Baffle, 02 engineering and technology, Reynolds stress, Micro-PIV, 01 natural sciences, 010305 fluids & plasmas, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], symbols.namesake, Cross section (physics), 0203 mechanical engineering, [SDV.SA.STA]Life Sciences [q-bio]/Agricultural sciences/Sciences and technics of agriculture, 0103 physical sciences, Fluid Flow and Transfer Processes, Physics, RSM model, Turbulence, Mechanical Engineering, Reynolds number, Mechanics, Vortex identification, Vorticity, Condensed Matter Physics, 6. Clean water, Vortex, 020303 mechanical engineering & transports, symbols
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]GEUSI [ADD1_IRSTEA]Gestion intégrée de la ressource et des infrastructures; International audience; The labyrinth-channel is largely used in dripper systems. The baffles play an important role to generate the head losses and induce the flow regulation on the drip irrigation network. But they also develop vorticity regions where the velocity is low or zero. These vorticity regions promote the deposition of particles or other biochemical development causing dripper clogging. The flow in the dripper labyrinth-channel must be described to analyze dripper clogging sensibility which drastically reduces its performance. This characterization is performed experimentally using the micro-particle-image-velocimetry (Micro-PIV) method, and numerically using the RSM Simulation. In this study, Micro-PIV experiments allow to analyze the flow in ten-pattern repeating baffles which reproduce the micro-irrigation dripper. The cross section is equal to 1 mm 2 and the inlet Reynolds number varies from 345 to 690. The present study first introduces a global analysis of the flow through the mean velocity modulus, the Reynolds stresses u , 2 v 2 and u v and the turbulence Reynolds number. Then, results for the mean strain rate and the mean spanwise vorticity are presented and discussed. Next, advanced methods of vortex detection are introduced and analyzed to better distinguish the vortex zones and to determine the vortex sizes. Furthermore, the numerical model is used to validate and analyze in a more detailed way the experimental results obtained by Micro-PIV.

Published
2019

8. Modelling of solid / liquid fractionation of trace metals for suspended sediments according to the hydro-sedimentary conditions of rivers - Application to 137Cs in the Rhône River (France)

Author

Fabien Anselmet, Olivier Radakovitch, Mohamed Krimissa, Hugo Lepage, Frédérique Eyrolle, Patrick Boyer, Muriel Amielh, Wirginia Tomczak, IRSN, PSE-SRTE-LRTA, EDF R&D (EDF R&D), EDF (EDF), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire de recherche sur les transferts des radionucléides dans les écosystèmes aquatiques (IRSN/PSE-ENV/SRTE/LRTA), Service de recherche sur les transferts et les effets des radionucléides sur les écosystèmes (IRSN/PSE-ENV/SRTE), and Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN)

Subjects
Environmental Engineering, Watershed, 010504 meteorology & atmospheric sciences, Water flow, Context (language use), Fractionation, 010501 environmental sciences, 01 natural sciences, River systems, Kd modelling, Trace metal, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Suspended sediments, Ecological Modeling, Particle size, 6. Clean water, Colloidal pumping, Partition coefficient, 13. Climate action, Environmental chemistry, Soil water, Environmental science, Sedimentary rock, Software
Abstract

International audience; The behavior and impact of trace metals discharged into rivers depend on their solid/liquid fractionation and the fate of these two phases according to hydro-sedimentary processes. The solid/liquid fractionation depends on many environmental factors which imply uncertainties of several orders of magnitude in the evaluation of the partition coefficients, whether by geochemical modelling, in situ measurements or sorption-desorption experiments. In this context, this paper presents a model of solid/liquid fractionation of trace metals with suspended sediments in rivers which integrates the hydro-sedimentary conditions and the properties of the watershed. Its comparison with the 137Cs concentrations measured in the Rhône River (France) thanks to monitoring shows that the solid/liquid fractionation of 137Cs with suspended sediments in rivers depends on chemical processes but also and above all on variations in water flow rate, size and load of suspended sediments and the balance between anthropogenic discharges and the average trace metal content of soils in the watershed.

Published
2021

9. Acknowledgement to Reviewers of Fluids in 2018

Author

Yoshiyuki Tagawa, Ali Bakhshandeh Rostami, Radwin Askari, Sergio Chiva, Caleb Brooks, Moon Son, Brandon L. Helfield, Jorge Peixinho, Thomas Gomez, Jiming Bao, Raghavendra Krishnamurthy, Luca Biferale, Karen Mulleners, Charlie Lin, Vincent Faucher, Sandra Rafael, Małgorzata Król, Albert Oliver, Pierre Thibault, Zhaoming He, Dragan Marinkovic, Julio Marti, Abbas Firoozabadi, Melanie Jimenez, Mercedes Fernández, Samane Zeyghami, Roman Chertovskih, Petros J. Ioannou, Valentina Domenici, Ramon Pamies, Claude Inserra, Jamal Naser, Karl W. Bandilla, Mark A. Stremler, Wei Tao Wu, Sayantan Ganguly, Mehdi Habibi, Yannis Dimakopoulos, Yancheng Zhang, Laurent Cordier, Holger Foysi, Sina Rezaei-Gomari, Lance Traub, Tuyen Quang Le, Thomas Baboolal, Albino Martins, Takashi Watanabe, Tannin Schmidt, Giancarlo Sorrentino, Valerio Pini, Ali Tafarojnoruz, Chengyu Li, Ans Punt, Shyy Woei Chang, John Methven, Konstantinos Verdelis, Stephen Hoath, D. Felipe Gaitan, Maria Alzira Pimenta Dinis, Mehrdad Massoudi, Arnold J. T. M. Mathijssen, Yasuyuki Maki, Hamid Arastoopour, Ali K. Oskouie, Peter D. Minev, Elna Heimdal Nilsson, Naum Gershenzon, Razvan Stefanescu, Patrick Richard, Vivek V. Ranade, John F. Mejia, Karsten Trulsen, Amin Doostmohammadi, Jung Il Choi, Mohammad Hashemi, Quoc Nguyen, Luis G. Baltazar, James S. Bus, Stefano Benni, David French, Ian Jacobi, Abraham N. Gissen, Chengcheng Tao, Ciro Apollonio, Marwan Fahs, Ismael Falcon Suarez, Traian Iliescu, Guillaume Roullet, Wei Lun Hsu, E. Eric Adams, Jose Alvarado, Ali Shafiei, Antonio Monzón, Alan J. Thorpe, Brian Helenbrook, Nicolas Espinoza, Takahiro Tsukahara, Dieter Braun, Tsevi Beatus, Jasmina Casals Terre, Tarak Nath Nandi, Marco Scapinello, Ahmad Malekpour, Georgios Martinopoulos, Mikhail A. Sheremet, David J. Collins, Pavel Kopel, William B. Zimmerman, Adnan Rajib, Ekaterina Ezhova, Alejandro D. Rey, Christian Nayeri, Cristian Marchioli, Antonio Perazzo, Alois Peter Schaffarczyk, Grazia Leonzio, Sunny Jung, Florent Malloggi, Franco Concli, David G. Dritschel, Fangxin Fang, Mostafa Safdari Shadloo, Pedro Dinis Gaspar, Michael Hargather, Chris Walcek, Dimitri Gidaspow, Lars Göran Westerberg, Diego Romano Perinelli, Guilhem Poy, Xuping Xie, Ken Kamrin, Daniela Malcangio, Ioannis Papantoniou, Ilias G. Papakonstantis, Mario Oertel, Thanh Toan Tran, Ioan Pop, Laurent Duchemin, Kelly M. Schultz, Javier Rodriguez-Rodriguez, Pejman Tahmasebi, Gergely Kristóf, Ke Xu, Greg Burgreen, Scott Mccue, Reza Barati, Ali Cemal Benim, Xuan Mu, Hamid Emami-Meybodi, John Bartzis, Zelin Xu, Carlos Borrego, Chadi Maalouf, Ulrike Müller, Hari B. Vuthaluru, Emil-Alexandru Brujan, Qingan Li, Kakkattukuzhy Isaac, Mahnoush Babaei, Juan Garrido-Jurado, Gualtiero Badin, Khashayar Khoshmanesh, Elsen Tjhung, Rita Carvalho, Robert Ettema, Xavier Carton, Shigeo Yoshida, Antal Jakli, Aleksey S. Telyakovskiy, Shohel Mahmud, Daniele Chiappini, Vít Průša, Alistair Revell, Thomas Engles, Evangelos Keramaris, Francesca Lionetto, Robin Singh, Evgeny Ryzhov, Wouter Zijl, Citsabehsan Devendran, Omar Basha, Rene Woszidlo, Joseph Tribbia, Amelia Carolina Sparavigna, Manfred Wagner, Michele Palermo, Umberto Morbiducci, Francesca Oliviero, Dima Bolmatov, Georgios Dimitrakopoulos, Javier Atencia, Víctor Vilarrasa, Chirag Trivedi, Raffaele Marino, J. C. Vassilicos, Hai Yao Deng, Petra Amparo López-Jiménez, Jorge Morillo, John Wanjiku, Gerardo Severino, Konstantin V. Koshel, Sahil Sandesh Gandhi, Ijung Kim, Philippe Sucosky, Joshua Bostwick, Robert A. Van Gorder, Davide Gardini, Tore Flåtten, Monirosadat Sadati, Enrico Ferrero, John J. Socha, Dmitri Kondrashov, Jinchen Ji, Julio Garcia, John Crawshaw, Wen Dar Guo, Mauro Scungio, Roberto Mauri, Alexander A. Schekochihin, Yaocihuatl Medina, Benjamin M. Friedrich, Gilles Bouchet, Cosimo Bianchini, Marek Stastna, Pradeep Sharma, Ashkan Vatani, David M. Dudzinski, Manicham Sivakumar, Juho Lintuvuori, Icíar González, Michael Nones, Seyyed Muhammad Salili, Andrew R. Teixeira, Geng Liu, Fardin Khalili, Ram Balachandar, Giorgio Besagni, Nivesh K. Mittal, Raf Theunissen, Anastasios J. Karabelas, Ramis Örlü, Markus Scholle, Adam Jirásek, Jens Olaf Delfs, Ricardo Vinuesa, Georgi Sutyrin, Stephen Wilson, Sébastien Poncet, Ardalan Javadi, Jean Lou Dorne, Yoshiaki Uchida, Bo Kong, Lauren E. Beckingham, Rossella Arrigo, Oxana E. Kurkina, Soo Kim Jeong, Francesco Meneguzzo, Kazumichi Kobayashi, Alex Skvortsov, Michalis Xenos, Davide Ferraro, Vitaliy Krivets, Mudde Rob, Eugene Benilov, Han Hu, Chandrashekhar S. Jog, Laura Miller, Omer San, Nikolai Brilliantov, Annalisa Dalmoro, Gaojin Li, Arthur E.P. Veldman, Iman Borazjani, Kongchang Wei, Luigi De Luca, Vladislav Zheligovsky, Kumbakonam R. Rajagopal, Raul Sanchez, Masaki Kubo, Rajib L. Goswamee, Zeynep Aytac, Nils T. Basse, Yuliang Xie, Saurin Patel, Mauro Malvé, Majid Mohammadian, Patrice Estelle, Bernd R. Noack, Christian Breitsamter, Layachi Hadji, Kim Boon Lua, Yongxing Wang, Ellahi Rahmat, Marco Evangelos Biancolini, Alberto Alberello, Andreas Gross, Xiangdong Li, Giuseppe Oliveto, Thomas Blacker, Samim Ali, Azar Eslam-Panah, Bo Cheng, Neil M. Ribe, Kaspar Vereide, Ryohji Ohba, Josep Maria Soler, Min Chan Kim, Albert Kwan, Astolfi Davide, Corina Drapaca, Ruth Baltus, Liqiang Ren, Anabela Maia, Gilad Arwatz, Paul Manneville, Marco Pellegrini, Vlassios Hrissanthou, Mohsen Soleimani-Mohseni, T. Juan García, Adriano Tiribocchi, Daniel Bonn, Michael S. Triantafyllou, Yan Zhang, Ali M. Hamed, Peiman Valipour, Mohsen Besharat, Lev A. Ostrovsky, Mauro Giudici, M. N. Islam, Sergey Suslov, Eric Climent, Dahai Qi, Dimitris Ipsakis, Vilhjálmur Nielsen, Leon Glicksman, Julio Martinell, Keith W. Moored, Dejan Brkić, Roman Mukin, Atle Jensen, Dimitris Drikakis, Fabien Anselmet, Vahid Dokhani, Soledad Le Clainche, Jozsef Rohacs, Yehuda Zeiri, D. J.E.M. Roekaerts, Daniel R. Einstein, Aashwin Mishra, Navid Kashaninejad, Yaoyi Guan, Erich Carr Everbach, Aliyu M. Aliyu, Alexander M. Balk, Hamidreza Shabgard, Alexander Doinikov, Jerome Charmet, Elizabeth H. Keating, Erico Luiz Rempel, Rui Sun, Hassan Dashtian, Lampros Vasiliades, Dmitry Kolomenskiy, Leon Wang, Hyeun Joong Yoon, V. L. Zimont, Shigeru Ikeo, Fernando Nardi, Odin Gramstad, Andrew Hazel, Stefano Discetti, C.D. Dritselis, Ignacio Pagonabarraga, Manfred Heuberger, Viatcheslav Bykov, Miroslav Stayanov, Mohammed Azaroual, Amirhossein Arzani, Abubakar Abbas Jibrin, Junru Wu, Alberto Meiss, Robert Stahelin, Mohammad Robiul Hossan, Walter Grondzik, Susan Kurien, Kyung Hwan Kwak, Peter Sunderland, Philippe Marmottant, and Dana Grecov

Subjects
Fluid Flow and Transfer Processes, Medical education, n/a, Mechanical Engineering, lcsh:QC310.15-319, Acknowledgement, lcsh:Descriptive and experimental mechanics, Hardware_ARITHMETICANDLOGICSTRUCTURES, lcsh:Thermodynamics, Condensed Matter Physics, Psychology, lcsh:QC120-168.85
Abstract

Rigorous peer-review is the corner-stone of high-quality academic publishing [...]

Published
2019

10. Impact of hydrodynamics on clay particle deposition and biofilm development in a labyrinth-channel dripper

Author

Juliette Schillings, Ryad Bendoula, Fabien Anselmet, Jafar Al-Muhammad, Séverine Tomas, Nassim Ait-Mouheb, Muriel Amielh, Centre de Montpellier [IRSTEA], Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Information – Technologies – Analyse Environnementale – Procédés Agricoles (UMR ITAP), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Laboratoire des Essais et Recherches des Matériaux d'Irrigation, Irstea, Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), and Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro

Subjects
Materials science, Fouling, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph], 0207 environmental engineering, Soil Science, 04 agricultural and veterinary sciences, 02 engineering and technology, 6. Clean water, Vortex, Clogging, Turbulence kinetic energy, 040103 agronomy & agriculture, Fluid dynamics, 0401 agriculture, forestry, and fisheries, Particle, Deposition (phase transition), [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Composite material, 020701 environmental engineering, Agronomy and Crop Science, ComputingMilieux_MISCELLANEOUS, Water Science and Technology, Particle deposition
Abstract

To better understand the physical and biological clogging in drip-irrigation, a study was conducted on the impacts of hydrodynamic conditions on clay particle deposition and biofilm development in drippers using an optical method. A transparent milli-fluidic system composed of labyrinth channels was used to identify areas most susceptible to particle clogging using two different types of clay suspensions: sodium bentonite and kaolin. The impact of salt addition [(NaCl) = 200 mg L− 1] on the clay deposition was also analyzed. Biofilm development was studied using the same methodology using a nutritive solution (chemical oxygen demand, COD = 200 mg L−1). In addition, fluid dynamics simulations were performed along the labyrinth channel to understand the effect of flow behaviour on the fouling. Computational fluid dynamics results show two types of flow topology: high velocity in the main flow (around 1 m s− 1) and low velocity in the vortex zones (less than 0.2 m s− 1) found in the channel corners. Using an optical method, kaolin deposition and biofilm growth in the dripper were observed to occur mainly in the inlet channel and initial vortex zones, which are characterized by lower mean velocity and turbulent kinetic energy values. This part of the dripper can be considered as a bottleneck that amplifies the fouling phenomena and which should be optimized. With the addition of NaCl, kaolin particles tend to form bigger flocs. Therefore, more significant particle deposition is observed, but this is not the case of bentonite for which no fouling is observed along the dripper.

Published
2019

11. Micro-PIV characterization of the flow in a milli-labyrinth-channel used in drip irrigation

Author

Muriel Amielh, Séverine Tomas, Jafar Al-Muhammad, Nassim Ait-Mouheb, Fabien Anselmet, Centre de Montpellier [IRSTEA], Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Laboratoire des Essais et Recherches des Matériaux d'Irrigation, Irstea, Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, and Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)

Subjects
Flow (psychology), Computational Mechanics, General Physics and Astronomy, Baffle, Drip irrigation, 01 natural sciences, 010309 optics, Clogging, symbols.namesake, 0103 physical sciences, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], ComputingMilieux_MISCELLANEOUS, Fluid Flow and Transfer Processes, Physics, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph], Turbulence, Reynolds number, 04 agricultural and veterinary sciences, Mechanics, Vorticity, 6. Clean water, Vortex, Mechanics of Materials, 040103 agronomy & agriculture, symbols, 0401 agriculture, forestry, and fisheries
Abstract

The baffle-fitted labyrinth-channel is largely used in drip irrigation systems. The existing baffles, which play an important role for generating head losses and ensure the flow regulation on the irrigation network, produce vorticity regions where the velocity is low or equal to zero. These vortices are likely to favor the deposition of particles or biochemical development causing dripper clogging which drastically reduces its performance. Flow topology in the dripper labyrinth-channel must be described to analyze dripper clogging sensibility and the effect on irrigation efficiency. Also, a question remains about the regime of this low Reynolds number flow. In the present study, the flow is characterized experimentally by micro-particle image velocimetry (micro-PIV) technique on ten-pattern repeating baffles used in drip irrigation dripper. Square cross-section is of about 1.4 mm $$^2$$ . Studied inlet Reynolds number varies from 345 to 690, which is equivalent to 1.4–2.8 l h $$^{-1}$$ . The mean velocity distribution and turbulence quantities within the labyrinth-channel flow are presented and discussed in this paper. The results underline that flow regime is turbulent and non-isotropic.

Published
2018

12. Eulerian atomization modeling of a pressure-atomized spray for sprinkler irrigation

Author

Muriel Amielh, Fabien Anselmet, Séverine Tomas, Ariane Vallet, C. Stevenin, Archéologies et Sciences de l'Antiquité (ArScAn), Université Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Information – Technologies – Analyse Environnementale – Procédés Agricoles (UMR ITAP), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Université Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Institut national de recherches archéologiques préventives (Inrap)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), and Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)

Subjects
Fluid Flow and Transfer Processes, Coalescence (physics), Materials science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph], Turbulence, Mechanical Engineering, Sauter mean diameter, Nozzle, Thermodynamics, 02 engineering and technology, Condensed Matter Physics, 01 natural sciences, 6. Clean water, Atomization, 010305 fluids & plasmas, Physics::Fluid Dynamics, 020303 mechanical engineering & transports, 0203 mechanical engineering, 0103 physical sciences, Turbulence kinetic energy, Volume fraction, Fluid dynamics, Convection–diffusion equation
Abstract

International audience; Abstract The objective of this study is the modeling of the atomization and dispersion of an irrigation water jet, from the nozzle outlet to the region of full development of the spray. The use of an Eulerian model, developed for high Reynolds and Weber numbers fluid flow, provides a continuous description of the process. In this model, the conservation equations are written for a two phase mixture. A transport equation for the volume density of the interface represents fragmentation/coalescence mechanisms and gives mean liquid fragments size. The numerical results obtained by this model were compared to experimental measurements of mean velocity, turbulent kinetic energy, liquid volume fraction and Sauter Mean Diameter. The model overestimates the decrease of the longitudinal velocity on the axis, but successfully predicts the volume fraction and mean droplet size profiles.

Published
2016

13. Experimental analysis of the flow characteristics of a pressure-atomised spray

Author

Séverine Tomas, Muriel Amielh, Ariane Vallet, Fabien Anselmet, Francisco Felis, Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), Information – Technologies – Analyse Environnementale – Procédés Agricoles (UMR ITAP), Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE)-Institut Agro - Montpellier SupAgro, and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Materials science, Nozzle, Flow (psychology), 02 engineering and technology, Reynolds stress, 01 natural sciences, 010305 fluids & plasmas, Spray, Physics::Fluid Dynamics, 0203 mechanical engineering, 0103 physical sciences, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Fluid Flow and Transfer Processes, Turbulence, Mechanical Engineering, Mechanics, Velocimetry, Condensed Matter Physics, Atomization, Droplet Tracking Velocimetry, Laser Doppler Velocimetry, 020303 mechanical engineering & transports, Optical probe, Turbulence kinetic energy, Volume fraction, Seeding, Experiments
Abstract

International audience; An experimental setup has been created to allow measurements of the properties of the gas phase, the liquid phase and the mixture in a pressure-atomised spray of water, in terms of both mean quantities and Reynolds stresses. This setup involves laser Doppler velocimetry for determining the velocity of either the gas or liquid phase, according to the parameters used, such as seeding or no-seeding of the ambient air, laser source power, or photo-multiplier gains, droplet tracking velocimetry for determining the velocity and characteristic size of the droplets, and a single optical probe for determining the mean volume fraction of the liquid, from which the liquid mean mass fraction and the mean density of the mixture are inferred. The experimental conditions, in particular in terms of liquid and gas Weber numbers, were chosen in a range for which the liquid phase turbulent kinetic energy should be mainly responsible for the liquid jetprimary break-up, these flow conditions lying within the second wind-induced atomization regime. Results reported herein are more specifically focused on the region ranging from 400 nozzle diameters to 800 nozzle diameters, where the liquid core is disrupted. They provide new information about the formation and properties of such pressure-atomised sprays, in particular in terms of the role played by the Reynolds stresses resulting from the slip velocity between the liquid and the gas. The mean slip velocity is directly related to the turbulent flux of liquid. Such information will be used in the future to develop new turbulence models since very limited experimental information is so far available for these terms.

Published
2020

14. Experimental and Numerical Investigations of the Aeroacoustics in a Corrugated Pipe Flow

Author

Pierre-Olivier Mattei, Gaëtan Galeron, Daniel Mazzoni, Fabien Anselmet, Muriel Amielh, Anselmet, Fabien, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), École Centrale de Marseille (ECM), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Sons, Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Mazzoni, Daniel, and ANR-10-EQPX-0029,EQUIP@MESO,Equipement d'excellence de calcul intensif de Mesocentres coordonnés - Tremplin vers le calcul petaflopique et l'exascale(2010)

Subjects
Engineering, Turbulence, business.industry, Acoustics, [SPI.FLUID]Engineering Sciences [physics]/Reactive fluid environment, Flow (psychology), Lattice Boltzmann methods, [SPI.FLUID] Engineering Sciences [physics]/Reactive fluid environment, 01 natural sciences, 010305 fluids & plasmas, Pipe flow, [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], Computer Science::Sound, 0103 physical sciences, Aeroacoustics, Physics::Accelerator Physics, [PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Boundary value problem, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], 010306 general physics, Sound pressure, business, [PHYS.MECA.ACOU] Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], ComputingMilieux_MISCELLANEOUS, Communication channel
Abstract

International audience; Our study is focused on the singing risers phenomenon which is encountered in corrugated channels under flow. Internal corrugations are responsible for flow instabilities that synchronize with longitudinal acoustic modes of the channel giving powerful pure tones. Experiments are performed in a specifically designed facility. Numerical simulations of the flow based on a lattice Boltzmann method (LBM) are faced to the experimental results. They aimed at investigating the ability of a LBM based simulation to predict the aeroacoustics of corrugated channels. Acoustic modes and turbulence in the corrugated channel are quite well predicted except the sound pressure levels that need better description of the acoustic boundary conditions.

Published
2018

15. An improved image processing method for particle characterization by shadowgraphy

Author

Séverine Tomas, Francisco Felis, Fabien Anselmet, Hua Wang, Muriel Amielh, DANTEC DYNAMICS SKOVLUNDE DNK, Partenaires IRSTEA, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)

Subjects
020301 aerospace & aeronautics, SHADOWGRAPHY, business.industry, Computer science, Process (computing), Particle characterization, Image processing, 02 engineering and technology, Shadowgraphy, 01 natural sciences, 010305 fluids & plasmas, Characterization (materials science), Image (mathematics), 0203 mechanical engineering, Simplicity (photography), 0103 physical sciences, Shadow, [SDE]Environmental Sciences, Particle, Computer vision, Artificial intelligence, business
Abstract

[EN] Shadowgraphy is one of the most popular imaging techniques to characterize moving particles by their size, geometry as well as velocity, due to its simplicity. However, it requires advanced image processing to handle various image defects such as non-uniform illumination, overlapped particles, etc., which are normally only solved for individual applications. This study proposes a robust image processing method for particle shadowgraphy, aiming to process imperfect particle shadow images. The proposed method first detects qualified particles from particle shadow images, and then processes detected particles individually. Therefore different defects from different particles can be handled separately and locally. An overlapped particles detection and separation algorithm is also implemented to improve the accuracy of size and geometry characterization. The proposed method is first proved by synthetic generated particle shadow images, followed by a proof test with shadow images from a transparent dot pattern target. Finally this method is successfully applied to a shadow image acquired from a water spray and proved to be able to handle various issues of shadowgraphy., This work is supported by a collaboration project among IRSTEA, IRPHE and Dantec Dynamics A/S, aiming to improve characterization of moving irregular particles by shadowgraphy measurements.

Published
2017

16. Dry deposition velocities of submicron aerosols on water surfaces: Laboratory experimental data and modelling approach

Author

Nevenick Calec, Alain Mailliat, Muriel Amielh, Fabien Anselmet, Patrick Boyer, Hubert Branger, Laboratoire de Modélisation Environnementale (DEI/SECRE/LME), Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Laboratoire de Modélisation Environnementale (IRSN/DEI/SECRE/LME), Service d'Etude du Comportement des Radionucléides dans les Ecosystèmes (IRSN/DEI/SECRE), Institut de Radioprotection et de Sûreté Nucléaire (IRSN)-Institut de Radioprotection et de Sûreté Nucléaire (IRSN), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Fluid Flow and Transfer Processes, Atmospheric Science, Environmental Engineering, Turbulent diffusion, 010504 meteorology & atmospheric sciences, Chemistry, Mechanical Engineering, Mechanics, 010501 environmental sciences, Atmospheric sciences, 01 natural sciences, Pollution, Thermophoresis, Aerosol, Deposition (aerosol physics), 13. Climate action, Diffusiophoresis, Relative humidity, Shear velocity, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], ComputingMilieux_MISCELLANEOUS, 0105 earth and related environmental sciences, Wind tunnel
Abstract

This article presents new experimental values of deposition velocities of submicron and hygroscopic aerosols of uranine with the objective to analyze dry deposition mechanisms of submicron aerosols on water surfaces in function of wind, water current and differences between air and water temperatures. A special attention is paid to phoretic effects which have been poorly considered by previous experimental studies. Experiments were performed in a laboratory wind tunnel for different conditions precisely characterized in function of aerosol size distribution, air turbulence, water current, water surface deformations, air and water temperatures and relative humidity. The experimental results do not allow detecting any effects of water current nor water surface deformation. The deposition velocity dimensionless with the friction velocity varies according to a V curve as a function of the air-water temperature difference. The minimum of this curve (≈ 2.0×10−5) is reached when the air-water temperature difference is equal to − 7.5 ° C . To analyse these experimental results, appropriate models of hygroscopicity growth, diffusiophoresis and thermophoresis are implemented in the Slinn resistance model ( Slinn & Slinn, 1980 ). Comparisons between experimental and modelling results confirm that the dry deposition velocity of submicron aerosol over water surface is mainly influenced by the turbulent diffusion and show that the influence of hygroscopicity growth is negligible. Furthermore, it is shown that adding the diffusiophoresis and thermophoresis velocities in the deposition layer transfer coefficient greatly improves the agreement between the experimental deposition velocity and the model. Particularly, these results reveal the important role of the thermophoresis when the air-water temperature difference becomes lower than -3 °C.

Published
2017

17. Méthode LSE appliquée à la résonance acoustique d'un tuyau corrugué sous écoulement

Author

Gaëtan Galeron, Muriel Amielh, Pierre-Olivier Mattei, Daniel Mazzoni, Fabien Anselmet, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Galeron, Gaëtan

Subjects
[PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.ACOU] Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph], [PHYS.MECA.ACOU]Physics [physics]/Mechanics [physics]/Acoustics [physics.class-ph]
Abstract

International audience; La dynamique de l'écoulement dans un tuyau corrugué est étudiée par des mesures par PIV couplées à des mesures de niveau de pression acoustique par microphones et de vitesse par fils chauds. L'objectif est d'utiliser la méthode LSE (Linear Stochastic Estimation) pour combiner la haute résolution spatiale des mesures par PIV à la haute résolution temporelle des mesures ponctuelles de vitesse et de pression par capteurs. On caractérise ainsi le lien entre l'aérodynamique et l'acoustique qui conduit à un sifflement intense sous certaines conditions d'écoulement dans le tuyau corrugué.

Published
2016

18. Acoustics, Aeroacoustics and Vibrations

Author

Fabien Anselmet and Pierre-Olivier Mattei

Subjects
Vibration, Physics, Acoustics, 0103 physical sciences, Aeroacoustics, 010306 general physics, 01 natural sciences, 010305 fluids & plasmas
Published
2016

20. Basic Theoretical Aeroacoustics Models

Author

Fabien Anselmet and Pierre-Olivier Mattei

Subjects
Physics, Classical mechanics, Acoustics, Aeroacoustics, Computational aeroacoustics, Acoustic wave, Noise level
Published
2016

22. Fluid Acoustics

Author

Fabien Anselmet and Pierre-Olivier Mattei

Published
2016

23. Vibrations of Thin Structures

Author

Fabien Anselmet and Pierre-Olivier Mattei

Subjects
Vibration, Materials science, Composite material
Published
2016

24. A Bit of History

Author

Fabien Anselmet and Pierre-Olivier Mattei

Subjects
Bit (horse), Computer science, Acoustics, Speech recognition, Sound propagation, Aeroacoustics, Sound production
Published
2016

25. Wave Propagation in Elastic Media

Author

Pierre-Olivier Mattei and Fabien Anselmet

Subjects
Physics, Lamb waves, Ground wave propagation, Wave propagation, Surface wave, Acoustics
Published
2016

26. Radiation, Diffraction, Enclosed Space

Author

Fabien Anselmet and Pierre-Olivier Mattei

Subjects
Diffraction, Physics, Optics, business.industry, Acoustics, Acoustic radiation, Radiation, Room acoustics, Space (mathematics), business
Published
2016

27. Acoustic Radiation of Thin Plates

Author

Fabien Anselmet and Pierre-Olivier Mattei

Subjects
Physics, Optics, Normal mode, business.industry, Acoustics, Plane wave, Acoustic wave equation, Fluid coupling, Acoustic wave, Acoustic radiation, business
Published
2016

29. Elements of Continuum Mechanics

Author

Fabien Anselmet and Pierre-Olivier Mattei

Subjects
Physics, Momentum, Conservation law, symbols.namesake, Classical mechanics, Peridynamics, Continuum mechanics, Analytical mechanics, symbols, Newton's laws of motion, Hamilton's principle, Control volume
Published
2016

30. Modeling a weak turbulent flow in a narrow and wavy channel: case of micro-irrigation

Author

Fabien Anselmet, Jafar Al-Muhammad, Séverine Tomas, Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Laboratoire des Essais et Recherches des Matériaux d'Irrigation, and Irstea

Subjects
Pressure drop, business.industry, Turbulence, Soil Science, Order (ring theory), Laminar flow, 04 agricultural and veterinary sciences, 02 engineering and technology, Mechanics, Computational fluid dynamics, Pipe flow, Physics::Fluid Dynamics, 020303 mechanical engineering & transports, Classical mechanics, 0203 mechanical engineering, Flow (mathematics), 040103 agronomy & agriculture, 0401 agriculture, forestry, and fisheries, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], business, Agronomy and Crop Science, Water Science and Technology, Mathematics, Common emitter
Abstract

[Departement_IRSTEA]Eaux [TR1_IRSTEA]GEUSI; International audience; The baffle-fitted labyrinth channel is commonly used in micro-irrigation systems. The flow in this labyrinth channel has a rather low-Reynolds number. In addition, emitter clogging, which is the major drawback of the micro-irrigation technique, is significantly related to flow characteristics. In order to design an anti-clogging emitter with a good performance, the hydrodynamics must be understood and analyzed. As CFD modeling is nowadays the most efficient approach for improving emitter geometry, this paper presents assessment of several k― \\\backslashvarepsilon\\ \epsilon turbulence models for computation of micro-irrigation emitter hydrodynamics. The objective is to determine the simplest and most efficient model to improve emitter conception, in terms of both discharge/pressure loss and limitation of the areas where low velocity is likely to generate emitter clogging. Low-Reynolds number k― \\\backslashvarepsilon\\ \epsilon models are often assumed to be more suitable for the labyrinth-channel flow since these models have no wall functions, they can take into account low turbulence levels and they account for the effect of damped turbulence. The low-Reynolds number k― \\\backslashvarepsilon\\ \epsilon models used in the present study are compared to high-Reynolds number k― \\\backslashvarepsilon\\ \epsilon models. Very different trends are observed between low-Reynolds number k― \\\backslashvarepsilon\\ \epsilon models. Some models reproduce a turbulent behavior, while others reproduce a laminar behavior. The head loss analysis reveals that, contrary to classical smooth pipe flow, the contribution of turbulent dissipation cannot be neglected since its contribution is larger than wall friction ones. This feature explains why different models can induce quite different flow behavior.

Published
2016

31. Flow characteristics of a large-size pressure-atomized spray using DTV

Author

Muriel Amielh, C. Stevenin, Ariane Vallet, Fabien Anselmet, Séverine Tomas, Archéologies et Sciences de l'Antiquité (ArScAn), Université Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Institut national de recherches archéologiques préventives (Inrap)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Gestion de l'Eau, Acteurs, Usages (UMR G-EAU), Institut de Recherche pour le Développement (IRD)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro)-AgroParisTech-Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad), Information – Technologies – Analyse Environnementale – Procédés Agricoles (UMR ITAP), Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-AgroParisTech-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut de Recherche pour le Développement (IRD), Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro)-Institut national d'enseignement supérieur pour l'agriculture, l'alimentation et l'environnement (Institut Agro), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Centre National de la Recherche Scientifique (CNRS), Centre de Coopération Internationale en Recherche Agronomique pour le Développement (Cirad)-Institut de Recherche pour le Développement (IRD)-AgroParisTech-Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA)-Institut national d’études supérieures agronomiques de Montpellier (Montpellier SupAgro), and Université Paris 1 Panthéon-Sorbonne (UP1)-Université Paris 8 Vincennes-Saint-Denis (UP8)-Université Paris Nanterre (UPN)-Ministère de la Culture et de la Communication (MCC)-Institut national de recherches archéologiques préventives (Inrap)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Fluid Flow and Transfer Processes, Jet (fluid), Materials science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph], Turbulence, business.industry, Mechanical Engineering, Nozzle, General Physics and Astronomy, Velocimetry, 01 natural sciences, 010305 fluids & plasmas, Spray nozzle, Atomization, 010309 optics, Physics::Fluid Dynamics, Optics, 0103 physical sciences, Dispersion (optics), Particle, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Anisotropy, business
Abstract

International audience; Abstract The purpose of this study is to characterize the atomization of a jet of water sprayed into the air at high velocity through a commercial nozzle widely used for sprinkler irrigation. The typical diameter of the droplets present in the spray is in the range of several tens of micrometers to several millimeters. They are visualized by ombroscopy. A specific Droplet Tracking Velocimetry (DTV) technique is developed to estimate the size and velocity of these highly polydispersed droplets that are distinctly non spherical. This analysis is performed from the rupture of the liquid core region (about a distance of 550 nozzle diameters) to the dispersed zone (about a distance of 900 nozzle diameters). With this technique, we obtain joint size-velocity measurements that are rarely produced. Especially two velocity components and also a large diameter range are characterized at the same time; while with other techniques, such as Particle Doppler Anemometry (PDA), the diameter range is quite reduced and requires specific settings. Additional measurements of the liquid volume fraction are performed using a single mode fiber-optic probe. In the light of our experimental data, it appears that the turbulent droplet motion in the spray is strongly anisotropic. This anisotropy is quite unexpected because other studies on sprays (generally concerned with engine applications) show a relatively low anisotropy. We attribute this increase of anisotropy to the fact that, for this type of spray, the droplet relaxation time is long in comparison to the characteristic time of the turbulence and that biggest droplets are still submitted to atomization process. This strong anisotropy is responsible for the poor radial dispersion of the spray.

Published
2016

32. Shape influence on mean forces applied on a ground vehicle under steady cross-wind

Author

Fabien Anselmet, Marc Gohlke, Muriel Amielh, and Jean-François Beaudoin

Subjects
Engineering, Renewable Energy, Sustainability and the Environment, business.industry, Mechanical Engineering, Flow (psychology), Context (language use), Mechanics, Structural engineering, Aerodynamics, Vortex, Aerodynamic force, Flow velocity, Moment (physics), business, Civil and Structural Engineering, Crosswind
Abstract

In this paper the flow around a vehicle under constant cross-wind is studied. The influence of shape changes on aerodynamic forces and moments as well as on flow structures is studied experimentally in a wind-tunnel. Tests are run at a flow velocity of 40 m/s on a 1/5th model of a mini-van type vehicle, which is yawed to an angle of − 30 ∘ . It is shown that small variations of the A-pillar radius have an important effect on the side-force and yawing moment. A link is made to the A-pillar vortex and its changes in intensity. The use of wind-tunnels represents a quite high budget in aerodynamic development. It is therefore quite important to limit the use of sophisticated measurement techniques to a strict minimum. In this context, the PIV-plane position proposed in this paper yields useful additional information to analyse the impact of form changes for example on cars under side-wind influence.

Published
2010

33. Experimental analysis of flow structures and forces on a 3D-bluff-body in constant cross-wind

Author

Jean-François Beaudoin, Marc Gohlke, Muriel Amielh, Fabien Anselmet, Anselmet, Fabien, PSA Peugeot-Citroen, PSA Peugeot Citroën (PSA), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)

Subjects
Flow visualization, Flow (psychology), Computational Mechanics, General Physics and Astronomy, [SPI.MECA.MEFL] Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], 02 engineering and technology, 01 natural sciences, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], 010305 fluids & plasmas, Physics::Fluid Dynamics, symbols.namesake, 0203 mechanical engineering, 0103 physical sciences, [PHYS.MECA.MEFL] Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Fluid Flow and Transfer Processes, Aerodynamics, Mechanics, Vortex, Euler angles, 020303 mechanical engineering & transports, Particle image velocimetry, Mechanics of Materials, Moment (physics), symbols, Geology, Crosswind
Abstract

The effect of cross-wind on a bluff-body in ground proximity is analysed experimentally. A recently introduced wind-tunnel model is used to analyse the effect of flow structures on the global forces and global moments. This study aims at creating a large database of the flow produced in the proximity of this bluff-body and giving some new insight into the physical mechanisms responsible for the increase in force in cross-wind situations. The importance of the model's lee side to the global yawing moment is put forward. Two vortices are identified and changes in the slope of the yawing moment versus yaw angle are attributed to their presence.

Published
2007

34. Numerical modelling of concentrated leak erosion during Hole Erosion Tests

Author

Fabien Anselmet, Pierre Philippe, Roland Borghi, Frederic Golay, Stéphane Bonelli, Florian Mercier, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Institut de Mathématiques de Toulon - EA 2134 (IMATH), Université de Toulon (UTLN), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), École Centrale de Marseille (ECM), ANR-08-COSI-0002,CARPEINTER,Grilles cartésiennes, pénalisation et suivi d'interface pour la simulation et l'optimisation d'écoulements complexes(2008), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), Risques, Ecosystèmes, Vulnérabilité, Environnement, Résilience (RECOVER), Aix Marseille Université (AMU)-Institut National de Recherche pour l’Agriculture, l’Alimentation et l’Environnement (INRAE), and Aix Marseille Université (AMU)

Subjects
Engineering, Turbulent flow modelling, Piping, business.industry, Turbulence, Laminar flow, Erosion coefficient, [SPI.MECA]Engineering Sciences [physics]/Mechanics [physics.med-ph], Geotechnical Engineering and Engineering Geology, Critical shear stress, 6. Clean water, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], [SPI]Engineering Sciences [physics], Critical resolved shear stress, Concentrated leak erosion, Solid mechanics, Fluid–structure interaction, Fluid-structure interaction, Earth and Planetary Sciences (miscellaneous), Erosion, Internal erosion, Geotechnical engineering, business
Abstract

This study focuses on the numerical modelling of concentrated leak erosion of a cohesive soil by a turbulent flow in axisymmetrical geometry, with application to the Hole Erosion Test (HET). The numerical model is based on adaptive remeshing of the water/soil interface to ensure accurate description of the mechanical phenomena occurring near the soil/water interface. The erosion law governing the interface motion is based on two erosion parameters: the critical shear stress and the erosion coefficient. The model is first validated in the case of 2D piping erosion induced by a laminar flow. Then, the numerical results are compared with the interpretation model of the Hole Erosion Test. Three HETs performed on different soils are modelled with a rather good accuracy. Lastly, a parametric analysis of the influence of the erosion parameters on erosion kinetics and evolution of channel diameter is conducted. Finally, after this validation by comparison with both the experimental results and the interpretation of Bonelli et al. [2], our model is now able to reproduce accurately the erosion of a cohesive soil by a concentrated leak. It also gives access to a detailed description of all the averaged hydrodynamic flow quantities. This detailed description is essential in order to achieve a better understanding of the erosion processes.

Published
2015

35. Settling classes for fine suspended particles

Author

Fabien Ternat, Muriel Amielh, Christophe Brach-Papa, Patrick Boyer, and Fabien Anselmet

Subjects
Marketing, Suspended solids, Work (thermodynamics), 010504 meteorology & atmospheric sciences, Strategy and Management, 0207 environmental engineering, Fluid mechanics, 02 engineering and technology, Mechanics, 01 natural sciences, 6. Clean water, Settling, Granulometry, Media Technology, Particle, Environmental science, General Materials Science, Two-phase flow, Turbidity, 020701 environmental engineering, 0105 earth and related environmental sciences
Abstract

The modelling of pollutant transfer in freshwater systems can be refined by considering the heterogeneities of the sedimentary dynamics and of the chemical reactivities of fine suspended particles. One of the first steps is the fractionation of these fine particles into effective settling classes. Although several methods exist, most of them are based on either granulometric considerations and/or arbitrary threshold criteria. This article presents the bases of an experimental method focusing on the direct measurement of the settling velocities without considering the granulometry and/nor any threshold criteria. The experimental work consists in recording the temporal evolution of the vertical distribution of the suspended solid concentration in a settling tank. A mathematical analysis provides the number of particle groups, and the mass contribution and the settling velocity for each This procedure is described and applied for validation, as a first step, to calibrated suspensions. Additional work is needed for a further analysis of the physical constraints involved in the model, as well as for more extensive experimental validation.

Published
2006

36. A dynamic box model to predict the radionuclide behaviour in rivers for medium and long-term periods

Author

Fabien Ternat, Patrick Boyer, Fabien Anselmet, Karine Beaugelin-Seiller, Muriel Amielh, Institut de Radioprotection et de Sûreté Nucléaire (IRSN), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)

Subjects
Abiotic component, Radionuclide, Biotic component, 010504 meteorology & atmospheric sciences, Consolidation (soil), Renewable Energy, Sustainability and the Environment, Health, Toxicology and Mutagenesis, Public Health, Environmental and Occupational Health, Soil science, 010501 environmental sciences, 01 natural sciences, Zooplankton, 6. Clean water, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], Water column, Nuclear Energy and Engineering, Macrobenthos, Phytoplankton, Environmental science, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Safety, Risk, Reliability and Quality, Waste Management and Disposal, 0105 earth and related environmental sciences
Abstract

This paper presents a dynamic box model for the radionuclide behaviour in rivers on medium- and long-term periods (several days to several years). The river is described as a succession of boxes representative of its different reaches. In each reach, the compartments are the water column and three bottom sediment layers. Called interface, the first layer plays a fundamental role for the vertical exchanges of solid radionuclide phases between the water column and the sediment. The second layer results from the consolidation of the previous one. Its interstitial water is mobile and the dissolved radionuclide phases can be exchanged with the water column. It is called active. The last layer results from the consolidation of the active layer. Its interstitial water is slightly mobile and it is assumed that its dissolved radionuclide phases cannot be exchanged. It is called passive. In each compartment, the model computes the temporal evolution of the radionuclide activities in the main abiotic and biotic components. The abiotic components are the water and different matter classes classified according to their deposit kinetics. The biotic components are phytoplankton, zooplankton, and fish distributed in planktonivorous and omnivorous species, in water column and macrobenthos in bottom sediment.

Published
2005

37. Turbulent Energy Scale-Budget Equations for nearly Homogeneous Sheared Turbulence

Author

Fabien Anselmet, Luminita Danaila, Tongming Zhou, Complexe de recherche interprofessionnel en aérothermochimie (CORIA), Université de Rouen Normandie (UNIROUEN), Normandie Université (NU)-Normandie Université (NU)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Nanyang Technological University [Singapour], Centre National de la Recherche Scientifique (CNRS)-Institut national des sciences appliquées Rouen Normandie (INSA Rouen Normandie), Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Normandie Université (NU)-Institut National des Sciences Appliquées (INSA)-Université de Rouen Normandie (UNIROUEN), Normandie Université (NU), and School of Mechanical and Aerospace Engineering [Singapore] (MAE)

Subjects
fully developed channel flow, K-epsilon turbulence model, General Chemical Engineering, General Physics and Astronomy, 01 natural sciences, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph], 010305 fluids & plasmas, Physics::Fluid Dynamics, hot-wire measurements, symbols.namesake, 0103 physical sciences, scale-by-scale energy budget equations, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Statistical physics, Physical and Theoretical Chemistry, 010306 general physics, Physics, Turbulent diffusion, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph], Turbulence, Kolmogorov microscales, Reynolds number, Mechanics, Open-channel flow, Turbulence kinetic energy, nearly homogeneous sheared turbulence, symbols, Shear flow
Abstract

For moderate Reynolds numbers, the isotropic relation between second-order and third-order moments for velocity increments (Kolmogorov's equation) is not respected, reflecting a non-negligible correlation between the scales responsible for the injection, transfer and dissipation of the turbulent energy. For (shearless) grid turbulence, there is only one dominant large-scale phenomenon, which is the non-stationarity of statistical moments resulting from the decay of energy downstream of the grid. In this case, the extension of Kolmogorov's analysis, as carried out by Danaila, Anselmet, Zhou and Antonia, J. Fluid Mech. 391, 1999 359–369) is quite straightforward. For shear flows, several large-scale phenomena generally coexist with similar amplitudes. This is particularly the case for wall-bounded flows, where turbulent diffusion and shear effects can present comparable amplitudes. The objective of this work is to quantify, in a fully developed turbulent channel flow and far from the wall, the influence of these two effects on the scale-by-scale energy budget equation. A generalized Kolmogorov equation is derived. Relatively good agreement between the new equation and hot-wire measurements is obtained in the outer region (40 < x+3 < 150) of the channel flow, for which the turbulent Reynolds number is Rlambda asymp 36.

Published
2004

38. Variable Density Fluid Turbulence

Author

P. Chassaing, R.A. Antonia, Fabien Anselmet, L. Joly, S. Sarkar, P. Chassaing, R.A. Antonia, Fabien Anselmet, L. Joly, and S. Sarkar

Subjects
Physics, Mechanics
Abstract

The first part aims at providing the physical and theoretical framework of the analysis of density variations in fully turbulent flows. Its scope is deliberately educational. In the second part, basic data on dynamical and scalar properties of variable density turbulent flows are presented and discussed, based on experimental data and/or results from direct numerical simulations. This part is rather concerned with a research audience. The last part is more directly devoted to an engineering audience and deals with prediction methods for turbulent flows of variable density fluid. Both first and second order, single point modeling are discussed, with special emphasis on the capability to include specific variable density / compressibility effects.

Published
2013

39. Sur l'évolution du taux moyen de dissipation de l'énergie cinétique de la turbulence dans une turbulence de grilleTransport equation for the homogeneous mean energy dissipation rate in decaying grid turbulence

Author

Tongming Zhou, Fabien Anselmet, Luminita Danaila, and R. A. Antonia

Subjects
Physics, Turbulence, Mechanical Engineering, Isotropy, Reynolds number, 02 engineering and technology, Mechanics, Dissipation, Vorticity, 01 natural sciences, Industrial and Manufacturing Engineering, Physics::Fluid Dynamics, symbols.namesake, 020303 mechanical engineering & transports, 0203 mechanical engineering, Flow (mathematics), 0103 physical sciences, Turbulence kinetic energy, symbols, General Materials Science, 010306 general physics, Convection–diffusion equation
Abstract

Grid turbulence is, from an academic viewpoint, a flow which permits various relations based on the assumption of local isotropy to be tested with a good deal of confidence if not rigour. However, in an experimental context, and for rather low Reynolds numbers, this flow does exhibit non-negligible departures from isotropy. This is why general relations based on weakly restrictive assumptions are required to provide a better description of the mechanisms involved in turbulence. The present paper presents an analytical work on the evolution behind the grid of the mean dissipation rate of the turbulent kinetic energy. More specifically, and for the sake of generality, we will consider the homogeneous form of this quantity, hom. The decay of hom mainly depends on two parameters, one representing the generation of vorticity by the action of the turbulent strain rate, and the other its destruction through molecular viscosity. Our equation is evaluated through the use of experimental data obtained in a low-Reynolds number grid turbulence, 32

Published
2003

41. A radioecological water quality model including a multi-class sedimentary dynamics approach. Presentation and comparison with a global approach

Author

Patrick Boyer, O. El Ganaoui, and Fabien Anselmet

Subjects
medicine.medical_specialty, Renewable Energy, Sustainability and the Environment, Hydraulics, Health, Toxicology and Mutagenesis, Public Health, Environmental and Occupational Health, Context (language use), Soil science, law.invention, Radioecology, Nuclear Energy and Engineering, Settling, law, medicine, Erosion, Environmental science, Sedimentary rock, Water quality, Safety, Risk, Reliability and Quality, Waste Management and Disposal, Deposition (chemistry)
Abstract

The assessment of the radionuclides transfers in the physical components of rivers (water, suspended sediments, bottom sediments) involves three disciplines : hydraulics, sedimentary dynamics and radioecology. In freshwater radioecological quality models, the radioecology is linked to the sedimentary dynamics through the adsorption / desorption process and the deposition / erosion fluxes. The assessment of these fluxes requires in-situ and laboratory experiments to determine their relating parameters (settling velocity, critical shear stress of deposition and erosion, etc.). The models do not usually distinguish the different mineral particle classes and make the assumption that deposition and erosion processes cannot occur simultaneously. However, natural water flow is characterized by a wide and continuous range of different mineral particle classes. As a consequence, the assumed threshold between deposition and erosion is reduced. For example, the deposition of one class can come along with the erosion of another class. In this context, we present a radioecological model which includes a multi-class sedimentary dynamics model. To show the difference between this approach and a global one (obtained for a single average class of matter), a comparison between these two approaches concludes this paper.

Published
2002

42. On the numerical modelling of the Hole Erosion Test

Author

Fabienne Mercier, Stéphane Bonelli, Pierre Philippe, Frederic Golay, Fabien Anselmet, Patrick Pinettes, Jean Jacques Fry, Institut national de recherche en sciences et technologies pour l'environnement et l'agriculture (IRSTEA), Ouvrages hydrauliques et hydrologie (UR OHAX), Institut de Mathématiques de Toulon - EA 2134 (IMATH), Université de Toulon (UTLN), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), geophyConsult (geophyConsult), GeophyConsult, EDF CIH, L. Cheng, S. Draper, H. An, and Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)

Subjects
[SPI]Engineering Sciences [physics], [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Mechanics of the fluids [physics.class-ph], Modelling and Simulation, [PHYS.MECA.MEFL]Physics [physics]/Mechanics [physics]/Fluid mechanics [physics.class-ph], Erosion and sedimentation, ComputingMilieux_MISCELLANEOUS
Abstract

International audience

Published
2014

43. Contrôle du sifflement d’un tuyau corrugué sous écoulement : analyse des données expérimentales

Author

Pierre-Olivier Mattei, Daniel Mazzoni, Cedric Pinhede, Muriel Amielh, Fabien Anselmet, Jiang Yan, Ulf Kristiansen, Laboratoire de Mécanique et d'Acoustique [Marseille] (LMA ), Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Sons, Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS), Institut de Recherche sur les Phénomènes Hors Equilibre (IRPHE), Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), NTNU Acoustics Research Center, Norwegian University of Science and Technology [Trondheim] (NTNU), Norwegian University of Science and Technology (NTNU)-Norwegian University of Science and Technology (NTNU), Institut Carnot STAR, Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM)-Centre National de la Recherche Scientifique (CNRS)-Aix Marseille Université (AMU)-École Centrale de Marseille (ECM), and Mattei, Pierre-Olivier

Subjects
[SPI.ACOU]Engineering Sciences [physics]/Acoustics [physics.class-ph], [SPI.ACOU] Engineering Sciences [physics]/Acoustics [physics.class-ph]
Abstract

International audience; Notre étude se concentre sur un phénomène souvent rencontré dans les tuyaux qui transportent des écoulements de gaz. Les instabilités de l'écoulement provoquées par les singularités géométriques internes au tuyau peuvent exciter les modes propres des tuyaux et induire des sons purs de forte puissance. Les exemples les plus usuels se rencontrent dans les jouets musicaux comme le ``Hummer'' ou dans les conduites de gaz des plates-formes de production de gaz naturel. Les expériences présentées dans cette communication visent à étudier plus en détail le couplage entre l'écoulement dans la conduite, la fluctuation d’écoulement induite par un champ acoustique basse fréquence et le bruit qui en résulte. Pour ce faire, un dispositif expérimental, équipé d'une source infrasonore dédiée et de parois rectangulaires en plexiglas transparent, a été spécialement conçu. Les mesures anémométriques à fil chaud et microphoniques prises au sein de l'écoulement ont été réalisées avec et sans oscillations acoustiques basse fréquence. Le traitement des signaux enregistrés a permis de situer la source d'instabilité à l'origine du sifflement à l'entrée du tuyau ainsi que le mécanisme d'établissement du sifflement par couplage avec les réflexions successives des fluctuations de pression aux extrémités du tuyau.

Published
2014

46. Modeling of Cauchy Tensor of Sliding Contacts

Author

Roland Borghi and Fabien Anselmet

Subjects
Cauchy elastic material, Cauchy stress tensor, Cauchy momentum equation, Mathematical analysis, Cauchy distribution, Tensor, Mathematics
Published
2014

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