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Purpose: This paper aims to propose a dedicated measurement methodology able to simultaneously determine the stability derivative Cmα̇ and the pitch damping coefficient sum Cmq + Cmα̇ in a wind tunnel using a single and almost non-intrusive metrological setup called MiRo. Design/methodology/approach: To assess the MiRo method's reliability, repeatability and accuracy, the measurements obtained with this technique are compared to other sources like aerodynamic balance measurements, alternative wind tunnel measurements, Ludwieg tube measurements, free-flight measurements and computational fluid dynamics (CFD) simulations. Two different numerical approaches are compared and used to validate the MiRo method. The first numerical method forces the projectile to describe a pure oscillation motion with small amplitude along the pitch axis during a rectilinear flight, whereas the second numerical approach couples the one degrees of freedom simulation motion equations with CFD methods. Findings: MiRo, a novel and almost non-intrusive technique for dynamic wind tunnel measurements, has been validated by comparison with five other experimental and numerical methodologies. Despite two completely different approaches, both numerical methods give almost identical results and show that the holding system has nearly no impact on the dynamic aerodynamic coefficients. Therefore, it could be assessed that the attitude of MiRo model in the wind tunnel is very close to the free-flight one. Originality/value: The MiRo method allows studying the attitude of a projectile in a wind tunnel with the least possible impact on the flow around a model. [ABSTRACT FROM AUTHOR]

A patent has been issued for data-driven plaque determination in medical imaging by Siemens Healthineers AG. The invention involves using synthetic data to train a machine-learning classifier to estimate hemodynamic metrics and predict plaque characteristics. By generating examples of anatomical arrangements and training classifiers, the technology aims to improve the accuracy of plaque determination in medical imaging. The patent emphasizes the use of synthetic data and machine learning to enhance the prediction of plaque-related characteristics in patients. [Extracted from the article]

A recent study conducted at the City of Hope National Medical Center in Duarte, California has developed a new method for measuring fluid dynamics in tumors using dynamic contrast-enhanced magnetic resonance imaging (DCE-MRI). The researchers used a localized convolutional function regression to simultaneously measure interstitial fluid velocity, diffusion, and perfusion in 3D. The method was validated computationally and experimentally, and when applied to human MRIs, it revealed tissue-specific differences in fluid dynamics between breast cancer and brain cancer. The researchers believe that this new method will contribute to a better understanding of cancer progression and therapeutic response. [Extracted from the article]

A patent has been issued to Philips Image Guided Therapy Corporation for systems and methods that help healthcare providers visualize important parameters in medical images. The invention provides an enhanced graphical display of images that define biological lumens and medical devices, allowing for the emphasis of various parameters through visual, audio, or tactile displays or alerts. The systems and methods are particularly useful for analyzing imaging data sets obtained from optical coherence tomography or ultrasound measurements, and they aim to speed up the review process and reduce potential errors during clinical evaluation. The patent also includes systems and methods for assessing imaging data sets related to biological structures, such as blood vessels, and for aiding in the evaluation of stent placement. [Extracted from the article]

Researchers from the Skolkovo Institute for Science and Technology in Moscow, Russia, have conducted a study on the permeability of gyroid-based porous structures used in bone tissue engineering. The study aimed to understand the relationship between the design parameters of these structures and their permeability. The researchers used in-plane measurements and computational fluid dynamics simulations to predict the properties of the structures before manufacturing them using laser powder bed fusion. The study also included biocompatibility assessments of the gyroid scaffolds using human cell culture experiments. The research was supported by the Russian Foundation for Basic Research and has been peer-reviewed. [Extracted from the article]

Keywords: Taiyuan; People's Republic of China; Asia; Alcohols; Health and Medicine; Hydrogel; Organic Chemicals; Peptide Hormones; Peptide Proteins; Polyethylene Glycols; Proinsulin EN Taiyuan People's Republic of China Asia Alcohols Health and Medicine Hydrogel Organic Chemicals Peptide Hormones Peptide Proteins Polyethylene Glycols Proinsulin 190 190 1 10/30/23 20231030 NES 231030 2023 OCT 30 (NewsRx) -- By a News Reporter-Staff News Editor at Diabetes Week -- A new study on Peptide Proteins - Proinsulin is now available. Keywords for this news article include: Taiyuan, People's Republic of China, Asia, Alcohols, Health and Medicine, Hydrogel, Organic Chemicals, Peptide Hormones, Peptide Proteins, Polyethylene Glycols, Proinsulin, Shanxi Medical University. [Extracted from the article]

A model of the secondary layer of wood cell wall consisting of crystalline cellulose, hemicellulose, and lignin is constructed and investigated with molecular dynamics simulations in the full range of hydration: from dry to saturated state. The model is considered a composite with the cellulose fibrils embedded in hemicellulose and lignin, forming a soft amorphous matrix. Its complex structure leads to nonlinear and anisotropic swelling and mechanical weakening. The water diffusivity through the pores is affected by an interplay between stiff cellulose fibers and weakening amorphous polymers. The formation and breaking of hydrogen bonds within the polymers and at the interfaces is found to be the underlying mechanism of adsorption-induced mechanical softening. The model is tested for adsorption isotherm, mechanical moduli, hydrogen bonds, and water diffusivity that all undergo a substantial change as the hydration increases. The determined physical and mechanical properties, changing with hydration, agree qualitatively with experimental measurements. [ABSTRACT FROM AUTHOR]

A level-set method is presented for computation of droplet impact and penetration into a porous medium. The volume averaged conservation equations of mass and momentum are employed for the porous region including the effects of porosity and drag force caused by the porous solid matrix. They are coupled to the conservation equations in the external fluid region through the matching conditions of velocity and stress on the porous surface. Computations are conducted to investigate the effects of initial droplet radius, impact velocity, contact angles, particle size and porosity on the droplet spreading and penetration. A simple analytical formulation is developed for the initial droplet penetration depth and compared with the numerical results. The present level-set method is also applied to the computation of droplet-droplet interaction in the porous medium. [ABSTRACT FROM AUTHOR]

The system of claim 1, wherein the processor is configured to: identify a first portion of the imaging data representative of the wall of the blood vessel; and identify a second portion of the imaging data representative of the stent. Tomographic imaging systems include, for example, optical coherence tomography systems, ultrasound imaging systems, and computed tomography. [Extracted from the article]

The distribution of porosity was examined on seven drill cores from west-central Alberta encompassing the Belle Fourche and Second White Specks Formations. These Cenomanian-Turonian mudrocks from the Western Canada Sedimentary Basin exhibit good organic richness (>2 wt. % total organic carbon) and marine kerogen type II with limited kerogen type III. With the increasing thermal maturity from approximately 0.43% vitrinite reflectance (R0) to approximately 0.90% Rol the total porosity decreases from approximately 9 to approximately 1 vol. %. This change translates to a reduction in total pore volume from approximately 0.05 to approximately 0.005 cm3/g and is accompanied by changes in relative proportions of micropore, mesopore, and macropore volumes. Variations in total porosity for the seven cores with different thermal maturities across Alberta are mainly related to mesoporosity and macroporosity, although the in-core variations in total porosity are mainly related to microporosity. In general, organic matter micropores contribute to the overall microporosity in the seven cores across the study area. The increase in the total pore volumes is in accordance with an increasing concentration of quartz, although increasing concentrations of chlorite and kaolinite may contribute to greater abundance of micropores in the seven cores. The in-core variations suggest that greater contents of kaolinite and illite may contribute to increasing mesopore volumes. Variations in pore volumes and pore size distribution with depth within individual cores (representing specific thermal maturity level) differ from what is observed laterally, when cores of various thermal maturity levels across Alberta are compared, indicating complex controls on porosity systems. [ABSTRACT FROM AUTHOR]

The Paleoproterozoic Barney Creek Formation (BCF; McArthur Basin, Australia) is one of the oldest active hydrocarbon systems on Earth with oil and gas shows present within organic-rich intervals (up to 7 wt. % total organic carbon). We combine bulk geochemical analyses, pore-space characterization, and high-resolution electron imaging techniques to characterize the evolution of the BCF pore system with maturity. A thermal gradient from the pre-oil window (0.48% calc. Ro) to gas window (1.01% calc. Ro) shows a progressive change in pore networks with the loss of organic-hosted pores dominant in thermally immature samples to porosity increasingly associated with the mineral matrix with thermal maturity. Precipitation of fine-grained, high surface area cements reduced porosity within the oil window, whereas feldspar and dolomite dissolution and creation of secondary pores increased porosity within the gas window. The abundance of feldspar grains (up to 50%) provided a significant potential for secondary pore formation as well as a source of silica and clay cement. This study identifies a first-order linkage between the chemically reactive sediments that are key to the reservoir properties in the BCF and a provenance and/or weathering intensity conducive to supplying fine-grained, mineralogically immature sediments during deposition. These findings likely apply more broadly to other chemically immature mudrocks typical of Precambrian age sediments or Phanerozoic settings subject to limited chemical weathering. [ABSTRACT FROM AUTHOR]

Pore types, pore size, and pore abundance vary systematically across thermal maturity in the Eagle Ford Formation, Maverick Basin, southern Texas. Scanning electron imaging of 20 samples from four wells is used to assess the complex response of pores to chemical and mechanical processes, entailing both destruction of primary porosity and generation of secondary pores. Primary mineral-associated pores are destroyed by compaction, cementation, and infill of secondary organic matter, whereas secondary pores are generated within organic matter (OM). Destruction of primary pores during early burial (to R0~0.5%) occurs by compaction of ductile detrital OM and clays and, to a lesser degree, as a result of cementation and infill of secondary OM. Larger pores are associated with coccolith debris. The dominant OM is spatially isolated detrital OM "stringers." Porosity is volumetrically dominated (average 6.2%) by relatively large, mostly interparticle mineral-associated pores (median size 51.6 nm [0.000002 in.]; detection limit near 3-4 nm [0.00000012-0.00000015 in.]). At low maturity, porosity and pore size correlate directly with calcite abundance and inversely with OM volumes. At higher maturity, further destruction of primary pores occurs through cementation, secondary OM infill, and greater compaction. Mineral-associated pores are present at high-maturity (R0~1.2%-1.3%), but are smaller (median size 30.2 nm [0.0000011 in.]) and less abundant (average of 2.5%) than at low maturity. A large portion of OM within high-maturity samples is diagenetic in origin and has pervaded into primary pore space, coating cement crystals, and filling intraparticle pores. Substantial mineral-associated porosity is locally present in samples where incursion of primary pore space by secondary OM has not occurred. Abundant secondary porosity is generated as OM matures into the wet-gas window. Porosity in most high-maturity samples is volumetrically dominated (average of 1.3%) by smaller, OM-hosted pores (median size 13.2 nm [0.00000051 in.]). [ABSTRACT FROM AUTHOR]

The 3D porosity obtained at different cooling rates in permanent mold castings was investigated. First, an aluminum alloy (1 0 .4% silicon) was poured into The 3D porosity obtained at different cooling rates in permanent mold castings was investigated. First, an aluminum alloy (10.4% silicon) was poured into permanent mold castings, and tensile samples that had solidified at different cooling rates were extracted from different areas of the molds. The porosity of these tensile samples was evaluated by computed tomography scanning, and the effect of the cooling rate on percentage volumetric porosity and tensile properties was investigated. The 3D volumetric porosity ranged between 0.004 and 0.023% in L-shaped samples with higher cooling rates, while it was between 0.012 and 0.066% in L-shaped samples with lower cooling rates. It was found that the cooling rate profoundly affected the volumetric porosity, and better mechanical properties were reported for higher cooling rates. This research is one of the first investigations into quantifying the 3D porosity of permanent mold aluminum alloy castings. [ABSTRACT FROM AUTHOR]

The article focuses on implementation of mutiparameter chemical analyzer in liquid analyzer that improves efficacy of measurement, prevents damage to analytical sensor and reduces cost per point of measurands. Topics discussed include requirement of signal card input to be scaled in the analyzer featuring HART transmissions, analyzer control function include propotional integral derivative, and requirement of an input-output port for association of secondary measurement with main measurement.

We measured the permeability of 30 samples extracted from 6 sets of compaction bands and the adjacent host rocks of the Jurassic aeolian Aztec Sandstone exposed in the Valley of Fire State Park in Nevada using core flooding experiments. The results show that the permeability within the high-angle compaction bands (three sets) is consistently three orders of magnitude lower than that of the host rocks. For the bed-parallel compaction bands, the measured permeability reduction is about half an order to three orders of magnitude for two sets of bands, and there is no detected permeability reduction for the samples from one set. For the samples that show permeability reduction within high-angle and bed-parallel compaction bands, the results are generally consistent with the data estimated from two-dimensional segmented image analyses in previous studies. Permeability of the samples used in the laboratory experiments was also obtained numerically based on three-dimensional tomographic images scanned from micro-samples and lattice-Boltzmann flow simulations. In addition, backscatter electron images (BEI) and energy dispersive spectroscopy images (EDSI) of thin sections were used to estimate the clay content inside and outside the bands. Large differences exist between the lab-based and image-based permeability and porosity measurements of compaction bands and host rocks. Possible factors causing these differences are different sample sizes and heterogeneities within the host rocks, calibration on the image segmentation, and incomplete characterization of clay minerals and fines migration during lab-based experiments. Given the wide range of permeability reductions within compaction bands of different orientations by different investigators, their impact on fluid flow should be evaluated case by case, one should consider their dimensions and distributions. [ABSTRACT FROM AUTHOR]

The article reports on the use of concepts of aerodynamics for the design of Formula 1 cars. The usage of computational fluid dynamics (CFD) and the balancing between computational fluid dynamics and the wind tunnels is discussed. It is mentioned that wind tunnel test could be replicated in pixels using CFD. Topics discussed also includes optimization challenge and data and translation and Additive Manufacturing and high-performance computing.

Purpose – The purpose of this paper is to study the effects of Angle of Attack (AOA), Axis Ratio (AR) and Reynolds number (Re) on unsteady laminar flow over a stationary elliptic cylinder. Design/methodology/approach – The governing equations of fluid flow over the elliptic cylinder are solved numerically on a Cartesian grid using Projection method based Immersed Boundary technique. This numerical method is validated with the results available in open literature. This scheme eliminates the requirement of generating a new computational mesh upon varying any geometrical parameter such as AR or AOA, and thus reduces the computational time and cost. Findings – Different vortex shedding patterns behind the elliptic cylinder are identified and classified using time averaged centerline streamwise velocity profile, instantaneous vorticity contours and instantaneous streamline patterns. A parameter space graph is constructed in order to reveal the dependence of AR, AOA and Re on vortex shedding. Integral parameters of flow such as mean drag, mean lift coefficients and Strouhal number are calculated and the effect of AR, AOA and Re on them is studied using various pressure and streamline contours. Functional relationships of each of integral parameters with respect to AR, AOA and Re are proposed with minimum percentage error. Practical implications – The results obtained can be used to explain the characteristics of flow patterns behind slender to bluff elliptical cylinders which found applications in insect flight modeling, heat exchangers and energy conservation systems. The proposed functional relationships may be very useful for the practicing engineers in those fields. Originality/value – The results presented in this paper are important for the researchers in the area of bluff body flow. The dependence of AOA on vortex shedding and flow parameters was never reported in the literature. These results are original, new and important. [ABSTRACT FROM AUTHOR]

The article offers information on a study conducted by Wouter Bos at the École Centrale de Lyon in France and his colleagues regarding the movements of the football players. Topics include the movement in a chaotic fluid flow, turbulent flow based on the faster and slower movement and higher or lower pressure, and calculation of how particles change directions.

Scanning acoustic microscopy (SAM) is a modern, powerful technology for visualizing the internal structure of solid samples. It uses high frequency ultrasonic waves to get information from inside in homogeneities and, therefore, is a sensitive, precise and safe technique for material characterization. It can be successfully used in scientific and research practices but has the greatest potential as a technology used in nondestructive quality evaluation. The present paper describes the methodology and different aspects of ultrasonic testing performed on a variety of industrial samples with a scanning acoustic microscope. The samples came from different areas of manufacturing and were intentionally chosen as revealing specific characteristics for different discontinuities. Acoustical images (B- and C-scans) were obtained with an optimized configuration of the microscope and analyzed for each sample. It was demonstrated that SAM technology can effectively detect, evaluate and classify imperfections: porosity in aluminum casting, undersized and cavernous resistance spot welds, low penetration depth of laser weld seams, insufficient or damaged areas of adhesive bonding of metals and fiber reinforced composites, and so on. The precision and value of the obtained acoustic images in some cases were proven by destructive testing. [ABSTRACT FROM AUTHOR]

Chalk constitutes challenging low-permeability reservoirs with porosity variations attributable to complex interactions between numerous processes. The influence of depositional processes, and thus the value of depositional models to predict porosity, is subject to continuing debate. In this study, a new approach is applied to investigate the influence of depositional and early post-depositional processes on chalk porosity, based on the 303 m thick Upper Cretaceous chalk succession in the Mona-1 core from the Danish North Sea. The influence of depositional processes on porosity is isolated by a mathematical correction of porosity data. Results confirm that mass-transport deposits are on average more porous than pelagites, whereas turbidites are less porous, given similar composition, burial history, and hydrocarbon migration history. The porosity variation between 12 chalk facies suggests that grain packing of the sediment in the consolidated state caused the facies-dependent porosity variation. Bioturbation caused a relatively tight grain packing compared with deposits that escaped bioturbation. Early plastic shear deformation of tightly packed bioturbated units resulted in dilative behaviour, which increased porosity, whereas more loosely packed units responded contractively, resulting in decreased porosity preservation. A firm understanding of chalk facies and thorough facies analyses are thus considered instrumental in chalk reservoir prediction. [ABSTRACT FROM AUTHOR]

Motivated by recent field observations, a laboratory model estuary experiment was conducted for the study of its flow and stratification. We find that a small inflow of cold freshwater, on top of warm saline water can lead to a large counter flow in the lower layer. This counter flow is part of a large aspect ratio convective cell driven by the horizontally varying diffusive cooling from above. Particle Image Velocimetry (PIV) measurement of the Reynolds stresses associated with transient tilted plumes embedded in this convective cell show that the viscous dissipation of the large-scale cellular flow is largely balanced by the Reynolds stress divergence of the tilted plumes. Using Optical Rotation measurements along with the PIV derived mean flow we find that the internal "salt" flux has Nusselt number (the ratio of convective to diffusive transport) of order 10³. Although the convection is vertically forced, the flow is essentially horizontal, and there is very little vertical mixing across the interface between the two layers. [ABSTRACT FROM AUTHOR]

Abstract: This study reports an experimental investigation of the non-linear phenomena of regular (classical) and irregular streaming patterns generated in an air-filled rigid-walled square channel subjected to the acoustic standing waves of different frequencies and intensities. The interaction of acoustic waves and thermoviscous fluids is responsible for these phenomena. The resonator’s walls are maintained at isothermal condition. Synchronized particle image velocimetry (PIV) technique has been used to measure the streaming velocity fields. The experimental results show that at a given excitation frequency, regular streaming flow patterns are observed up to a certain value of the excitation amplitude. As the amplitude increases beyond this limit, the regular streaming is distorted to an irregular flow structure. The regular and irregular streaming are classified in terms of streaming Reynolds number . It is found that for , classical streaming flow patterns are established and then deform to irregular and complex shapes as exceeds 50. [Copyright &y& Elsevier]

Abstract: This work is aimed at developing numerical methods to model the effects that particle deposit collected by fibrous filters has upon the flow field within the filter and hence upon further deposition. A numerical model of the flow field has been developed using the Boundary Element Method. The model contains a two-dimensional single fibre with the boundary conditions applied on the computational domain accounting for the neighbouring fibres. A layer of porous material is assumed to cover the fibre modelling deposited particulate. The width of the porous layer, which varies along the fibre surface, is defined by particle behaviour determined in earlier work, [Dunnett SJ, Clement CF, A numerical study of the effects of loading from diffusive deposition on the efficiency of fibrous filters. J Aerosol Sci 2006; 37: 1116–1139]. Once the flow field is known the motion of the particles in the flow is modelled. Small particles are considered where diffusion is the main mechanism by which they are captured by the fibres. Various situations are considered and the flow and particle behaviour investigated. In particular the effect of existing porous deposit on the fibres upon further deposition is studied. [Copyright &y& Elsevier]

Abstract: A computer program based on a potential-flow panel method was developed to evaluate the hydrodynamic forces acting on a harmonically heaving and pitching two-dimensional rigid foil. A new formulation of the unsteady Kutta condition, postulating a finite pressure difference at the trailing edge of the oscillating foil, is proposed and implemented in the numerical procedure. A comparison with published experimental data [Anderson JM, Streitlien K, Barrett DS, Triantafyllou MS. Oscillating foils of high propulsive efficiency. J Fluid Mech 1998;360(1):41–72; Read DA, Hover FS, Triantafyllou MS. Forces on oscillating foils for propulsion and maneuvering. J Fluids Struct 2003;17(1):163–83; Schouveiler L, Hover FS, Triantafyllou MS. Performance of flapping foil propulsion. J Fluids Struct 2005;20(7):949–59] showed good agreement with the computational results. The analysis of the experimental results indicates clearly that robust computational procedures are necessary for reliable data processing in terms of calibration, noise removal, correction factors, etc. The proposed two-dimensional approach to the problem is currently being developed as a three-dimensional procedure that will address the unsteady flow effects such as inertia-related ones that are currently omitted. [Copyright &y& Elsevier]

Abstract: The problem of unsteady compressible fluid flow in an enclosure induced by thermoacoustic waves is studied numerically. Full compressible set of Navier–Stokes equations are considered and numerically solved by boundary-domain integral equations approach coupled with wavelet compression and domain decomposition to achieve numerical efficiency. The thermal energy equation is written in its most general form including the Rayleigh and reversible expansion rate terms. Both, the classical Fourier heat flux model and wave heat conduction model are investigated. The velocity–vorticity formulation of the governing Navier–Stokes equations is employed, while the pressure field is evaluated from the corresponding pressure Poisson equation. Material properties are taken to be for the perfect gas, and assumed to be pressure and temperature dependent. [Copyright &y& Elsevier]

Abstract: The present study will give rise to better understanding of the airflow behaviour in a ceiling-slot ventilated enclosure partially filled with slotted porous boxes under isothermal conditions. Boxes were filled randomly with spheres of the same diameter. Laser Doppler velocimetry (LDV) measurements and computational fluid dynamics (CFD) predictions were carried out to characterize air velocity inside packed vented boxes. An original approach was also developed to evaluate the internal macroscopic velocities within the boxes by means of thermal sphere-shaped probes. LDV measurements and CFD predictions related to the main turbulent flow developed by the jet above the boxes were presented in the part I. Special attention was paid to the strong aerodynamic interactions observed on the top faces of the slotted boxes, between the external main flow and the return flow which predominate inside the boxes. Numerical and experimental data make it possible to evaluate the air ventilation levels and their heterogeneity for the different boxes. The RSM turbulence model gives reasonable agreement with experiments. [Copyright &y& Elsevier]

Abstract: A reduced-scale model and CFD predictions were used to investigate experimentally and numerically the airflow patterns within a ceiling slot-ventilated enclosure partially loaded with vented boxes filled by spherical objects. The experiments were carried out using laser Doppler velocimetry. Airflows around and inside porous boxes were predicted taking into account their aerodynamic interactions. This work is divided into two parts. This paper presents part I and concerns the air velocity characteristics within the jet above the boxes, while Part II deals with the air velocity characteristics inside the boxes. The results highlight the confinement effect due to the enclosure and the influence of load porosity on jet penetration, its development and hence the heterogeneity of ventilation within the enclosure. The numerical predictions obtained with the computational fluid dynamics Fluent package using the RSM turbulence model show reasonable agreement with experimental data. Predicted velocity profiles were generally within an error of 3–30% of the measured velocities. [Copyright &y& Elsevier]

Abstract: Computational fluid dynamic (CFD) studies of the flow inside a modelled human extra-thoracic airway (ETA) were conducted to evaluate the performance of several turbulence models in predicting flow inside this complex geometry. Veracity of the computational models is assessed for physiologically accurate flow rates of 10, 15, and 30l/min by comparison of numerical results with hot-wire [Johnstone A, Uddin M, Pollard A, Heenan A, Finlay WH. The flow inside an idealised form of the human extra-thoracic airway. Exp Fluids 2004;37(5):673–89] and particle image velocimetry (PIV) [Heenan AF, Matida E, Pollard A, Finlay WH. Experimental measurements and computational modelling of the flow field in an idealised extra-thoracic airway. Exp Fluids 2003;35:70–84] mean velocity data for the central sagittal plane of the ETA. Furthermore, flow features predicted by numerical models are compared to those from experimental flow-visualisation studies [Johnstone et al., 2004]. The flow in the ETA is shown to be highly three-dimensional, having strong secondary flows. [Copyright &y& Elsevier]

The article investigates the efficacy of a B-spline based higher order panel method (Hipan) over existing constant panel method in predicting flow quantities related with marine hydrodynamic problems. It provides a background of the Hipan and outlines the features of the B-spline representations and numerical formulations. The Hipan method was applied to two marine hydrodynamic problems, namely the flow around marine propellers and the flow around floating bodies including square box for the case of the sharp corner flow.

The article presents a paper which investigates the flow structure around short free and cylinders using 2- and 3-Component Particle Image Velocimetry (PIV). According to the article, the study discusses the three-dimensional flow field and how it was affected by inclination and porosity. It mentions the significant role to be played by integrated multi-trophic aquaculture for the aquaculture industry.

The article focuses on the approximation of irregular waves with elevated surface through interaction with sums of Stokes waves. The particle image velocimetry (PIV) system is noted to be used to measure wave kinematics in waves with freak origins. Topics about Yura wave, wave train and breaking wave are also discussed. Results of the study noted that the present analytical wave theories does not include the kinematics of breaking waves.

Abstract: The mixed-nonlinear Kosović, Leray and LANS-α subgrid scale models are contrasted with linear Smagorinsky and Yoshizawa large-eddy simulations for a Re =4000 plane jet simulation. Comparisons are made with direct numerical simulation data and reliable measurements. Global properties of the jet such as the spreading and centerline velocity decay rates are investigated. The mean-flow and turbulence parameters in the self-similar region are also studied. Mixed models developed for boundary layers compare well with the benchmark jet data and the linear model predictions. Differences between the models are minor and none showed any clear advantage in all the data comparisons. [Copyright &y& Elsevier]

Abstract: Sound generated by an airfoil in the wake of a rod is predicted numerically by using a Detached-Eddy Simulation (DES) unsteady flow field and a Ffowcs Williams and Hawkings acoustic analogy formulation for the far field computation. Volume sources from the rod wake are found to play a non-negligible role at high frequencies and surface contributions might be flawed if the surfaces cross highly turbulent flow regions even if surrounding volume terms are accounted for. The DES approach is based on a novel cubic explicit algebraic stress turbulence model which is built on a two-equation k–ε model from Lien and Lechziner. This DES has been recently implemented at the Berlin University of Technology in the compressible Navier–Stokes flow solver ELAN. The aerodynamic results are compared to experimental data obtained at the ECL by Jacob et al., as well as to previous Large Eddy Simulations results from the Proust/Turbflow code by Boudet et al. and DES simulations from Greschner et al. based on standard turbulence models. The acoustic analogy is applied both with and without volume terms to rigid and permeable control surfaces surrounding the rod–airfoil system. Aeroacoustic results are compared to experimental data from the literature, showing that the inclusion of volume terms improves the aeroacoustic prediction in the broadband high frequency range. [Copyright &y& Elsevier]

Abstract: Particle tracking in turbulent flows in complex domains requires accurate interpolation of the fluid velocity field. If grids are non-orthogonal and curvilinear, the most accurate available interpolation methods fail. We propose an accurate interpolation scheme based on Taylor series expansion of the local fluid velocity about the grid point nearest to the desired location. The scheme is best suited for curvilinear grids with non-orthogonal computational cells. We present the scheme with second-order accuracy, yet the order of accuracy of the method can be adapted to that of the Navier–Stokes solver. An application to particle dispersion in a turbulent wavy channel is presented, for which the scheme is tested against standard linear interpolation. Results show that significant discrepancies can arise in the particle displacement produced by the two schemes, particularly in the near-wall region which is often discretized with highly-distorted computational cells. [Copyright &y& Elsevier]

Abstract: The effectiveness of a sensor configuration for feedback flow control on the wake of a circular cylinder is investigated in both direct numerical simulation as well as in a water tunnel experiment. The research program is aimed at suppressing the von Kármán vortex street in the wake of a cylinder at a Reynolds number of 100. The design of sensor number and placement was based on data from a laminar two-dimensional simulation of the Navier–Stokes equations for the unforced condition. A low-dimensional proper orthogonal decomposition (POD) was applied to the vorticity calculated from the flow field and sensor placement was based on the intensity of the resulting spatial eigenfunctions. The numerically generated data was comprised of 70 snapshots taken over three cycles from the steady state regime. A linear stochastic estimator (LSE) was employed to map the velocity data to the temporal coefficients of the reduced order model. The capability of the sensor configuration to provide accurate estimates of the four low-dimensional states was validated experimentally in a water tunnel at a Reynolds number of 108. For the experimental wake, a sample of 200 particle image velocimetry (PIV) measurements was used. Results show that for experimental data, the root mean square estimation error of the estimates of the first two modes was within 6% of the desired values and for the next two modes was within 20% of the desired values. This level of error is acceptable for a moderately robust controller. [Copyright &y& Elsevier]

Deals with a study which presented a two-dimensional particle image velocimetry (PIV) system installed in a large-sized wind tunnel to examine the natural ventilation of fully open roof and Venlo-type multi-span greenhouses. Materials and methods; Ability to see flow patterns in and around a device under investigation; Comparisons of x-directional wind velocities computed by PIV and measured by an anemometer in the wind tunnel.

We report several new DØ measurements related to issues in QCD. Because of its large reach in x-Q2 and due to a thorough analysis of correlated systematic errors, the rapidity-dependent inclusive jet cross section has had a significant impact on the extraction of parton distribution functions. The ratios of jet and photon production at √s = 1800 and 630 GeV, although in general agreement with theory, indicate that not all aspects of these processes are fully understood. Studies of multiple jet production at moderate and low ET values have provided means to explore QCD scales and to tune the related aspects of event generators. A definitive signal for diffractive production of W bosons has been established, providing a new probe of the quark structure of the Pomeron. And, following on a great effort to bring up the experiment after a long shut-down and extensive upgrades, DØ is accumulating and analyzing new data at 2 TeV. The preliminary results for inclusive jet pT and dijet mass spectra are just the first steps in exploiting the opportunities that Run II of the Tevatron will provide. [Copyright &y& Elsevier]

The ability to simulate wall-bounded channel flows with second- and third-order shock-capturing schemes is tested on both subsonic and supersonic flow regimes, respectively at Mach 0.5 and 1.5. Direct numerical simulations (DNSs) and large-eddy simulations (LESs) are performed at Reynolds number 3000.In both flow regimes, results are compared with well-documented DNS, LES or experimental data.At Ma0=0.5, a simple second-order centred scheme provides results in excellent agreement with incompressible DNS databases, while the addition of artificial or subgrid-scale (SGS) dissipation decreases the resolution accuracy giving just satisfactory results. At Ma0=1.5, the second-order space accuracy is just sufficient to well resolve small turbulence scales on the chosen grid: without any dissipation models, such accuracy provides results in good agreement with reference data, while the addition of dissipation models considerably reduces the turbulence level and the flow appears almost laminar. Moreover, the use of explicit dissipative SGS models reduces the results accuracy.In both flow regimes, the numerical dissipation due to the discretization of the convective terms is also interpreted in terms of SGS dissipation in an LES context, yielding a generalised dynamic coefficient, equivalent to the dynamic coefficient of the Germano et al. [Phys. Fluids A 3(7) (1991) 1760] SGS model. This new generalised coefficient is thus developed to compare the order of magnitude of the intrinsic numerical dissipation of a shock-capturing scheme with respect to the SGS dissipation. [Copyright &y& Elsevier]

Discusses the use of molecular tagging velocimetry (MTV) in mapping the behavior of fluid flows. How MTV works; Uses of MTV in liquid-phase flows and gas-phase applications; Other applications of MTV.

Presents a computation of the consequences of the assumption of infinitesimal scales of turbulence on the estimates of dispersion for simple flows with oceanographic scales. Comparison of two models; Eddy-diffusion model; Homogeneous turbulence.

Discusses thermal and chemical methods in overcoming fluid behavior problems caused by hydrate and fluid constituents in subsea multiphase flow. Subsea production; Possible problems; Discussion on nucleation, growth and deposition; Preventing deposition; Thermal methods; Chemical inhibitors; Hydrate predictions; Multiphase flow; Hydrate inhibition.

Details an innovative calculation method that can easily determine the state of fluid flow and pressure losses in drilling and cementing operations. Importance of correct evaluation of the type of flow; Hydraulic parameters; Flow regimes for a circular and annular sections; Reynolds number; Evaluation criteria; Correlation between pressure loss gradient and GC; Rheological model.

• A new data assimilation technique for RANS simulation is presented. • The presented data assimilation technique is based on a state observer algorithm. • Both proportional and proportional-integral observers are considered. • The flow around a simplified car mirror geometry is used to evaluate the effectiveness of the proposed methodology. State observer techniques are investigated for the assimilation of three-dimensional velocity measurements into computational fluid dynamics simulations based on Reynolds-averaged Navier–Stokes (RANS) equations. The method relies on a forcing term, or observer, in the momentum equation, stemming from the difference between the computed velocity and the reference value, obtained by measurements or high-fidelity simulations. Two different approaches for the forcing term are considered: proportional and integral-proportional. This technique is demonstrated considering an experimental database that describes the time-average three-dimensional flow behind a generic car-mirror model. The velocity field is obtained by means of Robotic Volumetric PIV measurements. The effects of the different forcing terms and the spatial density of the measurement input to the numerical simulation are studied. The state observer approach forces locally the solution to comply with the reference value and the extent of the region modified by the forcing input is discussed. The velocity distribution and flow topology obtained with data assimilation are compared with attention to the object wake and the reattachment point where the largest discrepancy is observed between the different approaches. The results show that the integral term is more effective than the proportional one in reducing the mismatch between simulation and the reference data, with increasing benefits when the density of forced points, or forcing density, is increased. [ABSTRACT FROM AUTHOR]

The article reports on a study which examines the impact of a new fluid dynamic measurement tool on the development of consumer goods. Findings reveal that the said device can help monitor the rheology of liquids change during the manufacturing process which can lead to better control of liquid properties. The study notes that the device can also predict the flow of fluids under different conditions.

In a previous work, the feasibility of coupling magnetic resonance imaging (MRI) measurements and computational fluid dynamics (CFD) was presented, called CFD-MRI. Using a lattice Boltzmann based topology optimisation approach, the method can be described as a Navier–Stokes filter for flow MRI measurements. The main objective of this article is the analysis and quantification of CFD-MRI for its ability to reduce statistical measurement noise. For this, MRI data was analysed and used as basis for synthetic data, where noise was added to a simulation result. Thus, the noise-free data is known and a thorough analysis can be performed. The results show a very high agreement with the original data, even with high statistical noise in the input data and limited information available. • Coupling of computational fluid dynamics and magnetic resonance images using topology optimisation. • Analysis of noise in MRI data to create synthetic data. • Quantitative analysis of noise reduction capabilities. • Application to real data. [ABSTRACT FROM AUTHOR]