Search

Your search keyword '"Soulhac, Lionel"' showing total 126 results
Start Over Author "Soulhac, Lionel"
126 results on '"Soulhac, Lionel"'

1. High resolution wind-tunnel investigation about the effect of street trees on pollutant concentration and street canyon ventilation

Author

Fellini, Sofia, Marro, Massimo, Del Ponte, Annika Vittoria, Barulli, Marilina, Soulhac, Lionel, Ridolfi, Luca, and Salizzoni, Pietro

Subjects
Physics - Atmospheric and Oceanic Physics
Abstract

Greening cities is a key solution to improve the urban microclimate and mitigate the impact of climate change. However, the effect of tree planting on pollutant dispersion in streets is still a debated topic. To shed light on this issue, we present a wind-tunnel experiment aimed at investigating the effect of trees on street canyon ventilation. An idealized urban district was simulated by an array of blocks, and two rows of model trees were arranged at the sides of a street canyon oriented perpendicularly with respect to the wind direction. Reduced scale trees were chosen to mimic a realistic shape and aerodynamic behaviour. Three different spacings between the trees were considered. A passive scalar was injected from a line source placed at ground level and concentration measurements were performed in the whole canyon. Results show that the presence of trees alters the concentration pattern in the street with a progressive shift from a nearly two-dimensional to a three-dimensional field depending on tree density. Despite the significant change of the concentration field induced by trees, the average level of pollution in the street, and thus the overall ventilation efficiency, does not show a specific trend with the density of trees.

Published
2022
Full Text
View/download PDF

2. Simple photochemical modelling of NOX pollution in a street canyon

Author

Soulhac, Lionel, Fellini, Sofia, Nguyen, Chi Vuong, and Salizzoni, Pietro

Subjects
Physics - Atmospheric and Oceanic Physics
Abstract

To predict pollutant concentration in urban areas, it is crucial to take into account the chemical transformations of reactive pollutants in operational dispersion models. In this work, we derive and discuss different NO-NO2-O3 chemical street canyon models with increasing complexity and we analytically evaluate their applicability in different urban contexts. We then evaluate the performance of the models in predicting NO2 concentration at different locations within an urban district by comparing their predictions with measurements acquired in a field campaign. The results are in line with analytical speculations and give indications as to which model to use according to the conditions of the urban street canyon. In courtyards with limited ventilation and without direct emissions, the performance of the photostationary model is satisfactory. On the other hand, the application of a non-photostationary model significantly improves the predictions in urban canyons with direct vehicular emissions. The applicability of the proposed models in operational tools at the city scale is finally discussed.

Published
2022

5. UrMapSens: Joint Mapping-Sensing Design of Wireless Sensor Networks for Urban Environmental Monitoring

Author

Boubrima, Ahmed, Bechkit, Walid, Rivano, Herve, and Soulhac, Lionel

Abstract

In this article, we focus on the application of air quality monitoring where wireless sensor networks (WSNs) collect pollution measurements to estimate ground-truth pollution maps. We present UrMapSens, a novel WSN design strategy that aims to optimize the deployment locations of sensor nodes and the estimation of urban pollution maps. Unlike prior work, UrMapSens performs the optimization of both sensor deployment locations and pollution maps’ estimation in a joint way. We design our UrMapSens approach based on data assimilation by combining physical models’ simulations and expected sensor measurements in the estimation process of air pollution maps. We ensure a joint mapping-sensing design by determining the optimal number and locations of sensor nodes at the same time, in addition to finding the best way of assimilating the measurements that will be collected. Moreover, we use enhanced linearization techniques to provide a convex mathematical model based on mixed integer programming, which can be solved efficiently using numerical solvers. To validate UrMapSens in real-life scenarios, we designed an air pollution monitoring platform and used it to collect a dataset of nitrogen dioxide (NO2) concentrations in Lyon, France. Based on the experimentally collected dataset, we perform extensive evaluations of the proposed approach and show that our joint mapping-sensing design outperforms the prior work in which the optimization of sensor deployment locations and pollution maps’ estimation are performed independently.

Published
2024
Full Text
View/download PDF

10. DEVELOPING A RESEARCH STRATEGY TO BETTER UNDERSTAND, OBSERVE, AND SIMULATE URBAN ATMOSPHERIC PROCESSES AT KILOMETER TO SUBKILOMETER SCALES

Author

Barlow, Janet, Best, Martin, Bohnenstengel, Sylvia I., Clark, Peter, Grimmond, Sue, Lean, Humphrey, Christen, Andreas, Emeis, Stefan, Haeffelin, Martial, Harman, Ian N., Lemonsu, Aude, Martilli, Alberto, Pardyjak, Eric, Rotach, Mathias W, Ballard, Susan, Boutle, Ian, Brown, Andy, Cai, Xiaoming, Carpentieri, Matteo, Coceal, Omduth, Crawford, Ben, Di Sabatino, Silvana, Dou, Junxia, Drew, Daniel R., Edwards, John M., Fallmann, Joachim, Fortuniak, Krzysztof, Gornall, Jemma, Gronemeier, Tobias, Halios, Christos H., Hertwig, Denise, Hirano, Kohin, Holtslag, Albert A. M., Luo, Zhiwen, Mills, Gerald, Nakayoshi, Makoto, Pain, Kathy, Schlünzen, K. Heinke, Smith, Stefan, Soulhac, Lionel, Steeneveld, Gert-Jan, Sun, Ting, Theeuwes, Natalie E, Thomson, David, Voogt, James A., Ward, Helen C., Xie, Zheng-Tong, and Zhong, Jian

Published
2017

19. Investigation of a Gaussian Plume in the Vicinity of an Urban Cyclotron Using Helium as a Tracer Gas

Author

Laguionie, Philippe, primary, Connan, Olivier, additional, Tien, Thinh Lai, additional, Vecchiola, Sophie, additional, Chardeur, Johann, additional, Cazimajou, Olivier, additional, Solier, Luc, additional, Charvolin-Volta, Perrine, additional, Chen, Liying, additional, Korsakissok, Irène, additional, Guellec, Malo Le, additional, Soulhac, Lionel, additional, Tripathi, Amita, additional, and Maro, Denis, additional

Published
2022
Full Text
View/download PDF

29. Retrospective Modeling of NO2 and PM10 Concentrations over the Lyon Metropolitan Area (France), 1990–2010—Performance Evaluation, Exposure Assessment and Correlation between Pollutants

Author

Coudon, Thomas, Nguyen, Chi Vuong, Volta, Perrine, Grassot, Lény, Couvidat, Florian, Soulhac, Lionel, Gulliver, John, Mancini, Francesca Romana, Fervers, Béatrice, Salizzoni, Pietro, Département cancer environnement (Centre Léon Bérard - Lyon), Centre Léon Bérard [Lyon], Laboratoire de Mecanique des Fluides et d'Acoustique (LMFA), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), Institut National de l'Environnement Industriel et des Risques (INERIS), University of Leicester, Centre de recherche en épidémiologie et santé des populations (CESP), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Assistance publique - Hôpitaux de Paris (AP-HP) (AP-HP)-Hôpital Paul Brousse-Institut National de la Santé et de la Recherche Médicale (INSERM)-Université Paris-Saclay, and Civs, Gestionnaire

Subjects
[SDE] Environmental Sciences, particulate matter, long-term exposure, exposure assessment, nitrogen dioxide, [SDE]Environmental Sciences, air pollution, lcsh:Meteorology. Climatology, lcsh:QC851-999, complex mixtures
Abstract

Numerous cancers develop years after subjects have been exposed to chemical compounds. Thus, environmental epidemiological studies need to accurately reconstruct exposures over long periods. To estimate exposure to NO2 and PM10 concentrations, we modelled ground-level air concentrations, at very fine temporal (1 h) and spatial (10 m) resolutions, over a large European metropolitan area and at subject’s address of a French national cohort, for five different years (1990, 1995, 2000, 2005 and 2010). Model performances were assessed by comparing the annual modelled concentration against monitoring station measurements. As input data, we used background concentrations from a large-scale dispersion model. The relevance of our approach was assessed by comparing results in 2010, with a modelling using monitoring values as background data. The comparison with measurement data showed good performance of the model for the majority of the period, with a performance declined in 1990. Concentrations at the subject’s residence decreased by 45% for PM10 and 38% for NO2. The proportion of subjects exposed above the WHO recommendations declined from 100% to 50% for PM10 and from 79% to 16% for NO2. The results of this study would provide a reference for future models to assess chronic exposures to PM10 and NO2 on a larger scale.

Published
2021
Full Text
View/download PDF

35. Development of BUILD (Building Urban and Industrial Lagrangian Dispersion), a new operational dispersion model for accidental or deliberate releases in complex area

Author

Soulhac, Lionel, Lamaison, Guillevic, Volta, P., Slimani, Mehdi, Armand, Patrick, Patryl, Luc, Laboratoire de Mecanique des Fluides et d'Acoustique (LMFA), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and Commissariat à l'énergie atomique et aux énergies alternatives (CEA)

Subjects
[SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph]
Abstract

International audience; The release of CBRN toxic substances (Chemical, Biological, Radiological and Nuclear) into the atmosphere is an important issue for the safety of people and the protection of infrastructures, more specifically in the case of accidental or deliberate release within an urban or industrial complex-built area. In order to be able to react quickly and take decisions, first responders, public authorities and industrial companies need operational simulation tools for emergency situations. This paper presents the development and the physical parameterizations of a new operational dispersion model, called BUILD (Building Urban and Industrial Lagrangian Dispersion model), which is dedicated to simulate the transport of CBRN pollutants in complex built area. The BUILD model uses a geometrical preprocessor which converts 3D urban geometrical databases into 2D tiles of pre-calculated information on the street canyons, their connectivity and the recirculations in the wake of buildings. The BUILD flow model is based on a “SIRANE like” parametrization for the dense part of an urban area (Soulhac et al., 2011, 2012). Nevertheless, the flow model has been enhanced to consider the recirculating transverse component of the flow in each street and a three-dimensional diagnostic flow model in the roughness sublayer, to take into account the deviation by buildings and obstacles. In order to represent obstacles and buildings in sparse areas (isolated roughness regime), the BUILD model uses an analytical building wake parametrization to describe the recirculating flow downwind of a building. The transport and dispersion of pollutants are solved using a Lagrangian particles stochastic approach coupled with the simplified flow defined above. This new operational model is able to simulate the dispersion from a point source in a complex built area in a computational time less than one minute on a laptop. The present paper describes the physical parameterizations of the model and their calibration. A companion paper (Slimani et al., Harmo20) presents in more detail the validation against wind tunnel data and CFD RANS and LES simulations on obstacles and streets network configurations. © 2020 HARMO. All rights reserved.

Published
2020

36. CFD Rans and les simulations for the validation of the BUILD (Building Urban and Industrial Lagrangian Dispersion) model

Author

Slimani, Mehdi, Soulhac, Lionel, Lamaison, Guillevic, Armand, Patrick, Patryl, Luc, Donnat, Ludovic, Duclaux, Olivier, Commissariat à l'énergie atomique et aux énergies alternatives (CEA), Laboratoire de Mecanique des Fluides et d'Acoustique (LMFA), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS), and TOTAL Refining and Chemical

Subjects
Operational, Atmospheric dispersion model, Emergency response, Network of streets, Street canyon, [SPI.MECA.MEFL]Engineering Sciences [physics]/Mechanics [physics.med-ph]/Fluids mechanics [physics.class-ph]
Abstract

International audience; The atmospheric dispersion of CBRN (Chemical, Biological, Radiological and Nuclear) toxic substances, of accidental or intentional origin, on an urban or industrial complex built area, is a subject of major concern for the safety of people and the protection of infrastructures. In order to face these different types of risks and threats, industrial companies and public authorities need operational simulation tools for assessing, in advance or in emergency, the health consequences of harmful discharges on the population and on first responders. In this context, a new software called BUILD (Building, Urban and Industrial Lagrangian Dispersion model) has been developed to simulate the atmospheric dispersion of gases and particles in a complex built environment. In order to validate this new model, simulations have been performed on the wind tunnel experimental test case of continuous and instantaneous releases behind a 2D square obstacle (Gamel, 2015) and in a regular network of streets (Cierco et al., 2010, Ben Salem et al., 2015). Results of the operational BUILD model are compared with experimental data and with detailed CFD calculations.

Published
2020

42. Development of a new operational urban Lagrangian dispersion model for emergency response

Author

Slimani, Mehdi, Soulhac, Lionel, Lamaison, Guillevic, Armand, Patrick, Patryl, Luc, CEA DAM ILE-DE-FRANCE - Bruyères-le-Châtel [Arpajon] (CEA DAM IDF), Laboratoire de Mecanique des Fluides et d'Acoustique (LMFA), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

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

International audience

Published
2019

43. Developing a research strategy to better understand, observe and simulate urban atmospheric processes at kilometre to sub-kilometre scales

Author

Barlow, Janet, Best, Martin, Bohnenstengel, Sylvia I., Clark, Peter, Grimmond, Sue, Lean, Humphrey, Christen, Andreas, Emeis, Stefan, Haeffelin, Martial, Harman, Ian N., Lemonsu, Aude, Martilli, Alberto, Pardyjak, Eric, Rotach, Mathias W., Ballard, Susan, Boutle, Ian, Brown, Andy, Cai, Xiaoming, Carpentieri, Matteo, Coceal, Omduth, Crawford, Ben, Di Sabatino, Silvana, Dou, Junxia, Drew, Daniel R., Edwards, John M., Fallmann, Joachim, Fortuniak, Krzysztof, Gornall, Jemma, Gronemeier, Tobias, Halios, Christos H., Hertwig, Denise, Hirano, Kohin, Holtslag, Albert A. M., Luo, Zhiwen, Mills, Gerald, Nakayoshi, Makoto, Pain, Kathy, Schlünzen, K. Heinke, Smith, Stefan, Soulhac, Lionel, Steeneveld, Gert-Jan, Sun, Ting, Theeuwes, Natalie E., Thomson, David, Voogt, James A., Ward, Helen C., Xie, Zheng-Tong, and Zhong, Jian

Subjects
Earth sciences, ddc:550
Published
2017
Full Text
View/download PDF

44. Planification urbaine, environnement et santé : une étude sur Strasbourg

Author

Payre, Camille, Bardeau, Guillaume, Schillinger, Charles, Volta, Perrine, Soulhac, Lionel, Guillossou, Gaëlle, Piotrowski, Aleksandra, Guidici, Pascal, Laboratoire de Mecanique des Fluides et d'Acoustique (LMFA), École Centrale de Lyon (ECL), Université de Lyon-Université de Lyon-Université Claude Bernard Lyon 1 (UCBL), Université de Lyon-Institut National des Sciences Appliquées de Lyon (INSA Lyon), and Université de Lyon-Institut National des Sciences Appliquées (INSA)-Institut National des Sciences Appliquées (INSA)-Centre National de la Recherche Scientifique (CNRS)

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

International audience; no abstract

Published
2017
Full Text
View/download PDF

48. Poster

Author

Boubrima, Ahmed, primary, Bechkit, Walid, additional, Rivano, Hervé, additional, and Soulhac, Lionel, additional

Published
2017
Full Text
View/download PDF

49. Source Apportionment and Data Assimilation in Urban Air Quality Modelling for NO2: The Lyon Case Study.

Author

Nguyen, Chi Vuong, Soulhac, Lionel, and Salizzoni, Pietro

Subjects
*AIR quality, *AIR pollution, *DISPERSION (Atmospheric chemistry), *ATMOSPHERIC models, *METROPOLITAN areas, ENVIRONMENTAL conditions
Abstract

Developing effective strategies for reducing the atmospheric pollutant concentrations below regulatory threshold levels requires identifying the main origins/sources of air pollution. This can be achieved by implementing so called source apportionment methods in atmospheric dispersion models. This study presents the results of a source apportionment module implemented in the SIRANE urban air-quality model. This module uses the tagged species approach and includes two methods, named SA-NO and SA-NOX, in order to evaluate the sources' contributions to the NO2 concentrations in air. We also present results of a data assimilation method, named SALS, that uses the source apportionment estimates to improve the accuracy of the SIRANE model results. The source apportionment module and the assimilation method have been tested on a real case study (the urban agglomeration of Lyon, France, for the year 2008) focusing on the NO2 emissions and concentrations. Results of the source apportionment with the SA-NO and SA-NOX models are similar. Both models show that traffic is the main cause of NO2 air pollution in the studied area. Results of the SALS data assimilation method highlights its ability in improving the predictions of an urban atmospheric models. [ABSTRACT FROM AUTHOR]

Published
2018
Full Text
View/download PDF

Catalog

Books, media, physical & digital resources
See catalog results