A multiscale method for producing homogenized drag laws of a permeable medium by conflating experimental data with Lattice-Boltzmann simulations

2019 ◽  
Vol 29 (11) ◽  
pp. 4394-4407 ◽  
Author(s):  
Alejandro Clausse ◽  
Nicolás Silin ◽  
Gustavo Boroni
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Lattice Boltzmann ◽  
Particle Image ◽  
Numerical Calculations ◽  
Scale Model ◽  
Content Type ◽  
Micro Scale ◽  
Drag Forces ◽  
Image Velocimetry

Purpose The purpose of this paper is to obtain a permeability law of a gas flow through a permeable medium using particle image velocimetry experimental data as primal information, which is conflated with numerical calculations by means of a multi-scale method. Design/methodology/approach The D2Q9 single-relaxation-time Lattice Boltzmann model (LBM) implemented in GPU is used for the numerical calculations. In a first homogenized micro-scale, the drag forces are emulated by means of an effective Darcy law acting only in the close neighborhood of the solid structures. A second mesoscopic level of homogenization makes use of the effective drag forces resulting from the first-scale model. Findings The procedure is applied to an experiment consisting of a regular array of wires. For the first level of homogenization, an effective drag law of the individual elemental obstacles is produced by conflating particle image velocimetry measurements of the flow field around the wires and numerical calculations performed with a GPU implementation of the LBM. In the second homogenization, a Darcy–Forchheimer correlation is produced, which is used in a final homogenized LBM model. Research limitations/implications The numerical simulations at the first level of homogenization require a substantial amount of calculations, which in the present case were performed by means of the computational power of a GPU. Originality/value The homogenization procedure can be extended to other permeable structures. The micro-scale-level model retrieves the fluid-structure forces between the flow and the obstacles, which are difficult to obtain experimentally either from direct measurement or by indirect assessment from velocity measurements.

scholarly journals Experimental Validation of Falling Liquid Film Models: Velocity Assumption and Velocity Field Comparison

Polymers ◽  
2021 ◽  
Vol 13 (8) ◽  
pp. 1205
Author(s):  
Ruiqi Wang ◽  
Riqiang Duan ◽  
Haijun Jia
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Velocity Field ◽  
Experimental Validation ◽  
Particle Image ◽  
Velocity Fields ◽  
Number Range ◽  
Comparison Results ◽  
Image Velocimetry ◽  
Experimental Particle

This publication focuses on the experimental validation of film models by comparing constructed and experimental velocity fields based on model and elementary experimental data. The film experiment covers Kapitza numbers Ka = 278.8 and Ka = 4538.6, a Reynolds number range of 1.6–52, and disturbance frequencies of 0, 2, 5, and 7 Hz. Compared to previous publications, the applied methodology has boundary identification procedures that are more refined and provide additional adaptive particle image velocimetry (PIV) method access to synthetic particle images. The experimental method was validated with a comparison with experimental particle image velocimetry and planar laser induced fluorescence (PIV/PLIF) results, Nusselt’s theoretical prediction, and experimental particle tracking velocimetry (PTV) results of flat steady cases, and a good continuity equation reproduction of transient cases proves the method’s fidelity. The velocity fields are reconstructed based on different film flow model velocity profile assumptions such as experimental film thickness, flow rates, and their derivatives, providing a validation method of film model by comparison between reconstructed velocity experimental data and experimental velocity data. The comparison results show that the first-order weighted residual model (WRM) and regularized model (RM) are very similar, although they may fail to predict the velocity field in rapidly changing zones such as the front of the main hump and the first capillary wave troughs.

scholarly journals AN ATHEROSCLEROTIC CORONARY ARTERY PHANTOM FOR PARTICLE IMAGE VELOCIMETRY

2011 ◽  
Author(s):  
Jean Brunette ◽  
Rosaire Mongrain ◽  
Rosaire Mongrain ◽  
Adrian Ranga ◽  
Adrian Ranga ◽  
...  
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Heart Attack ◽  
Computational Models ◽  
Particle Image ◽  
Flow Analysis ◽  
Novel Technique ◽  
Image Velocimetry ◽  
Inflammatory Processes ◽  
Injection Molded

Myocardial infarction, also known as a heart attack, is the single leading cause of death in North America. It results from the rupture of an atherosclerotic plaque, which occurs in response to both mechanical stress and inflammatory processes. In order to validate computational models of atherosclerotic coronary arteries, a novel technique for molding realistic compliant phantom featuring injection-molded inclusions and multiple layers has been developed. This transparent phantom allows for particle image velocimetry (PIV) flow analysis and can supply experimental data to validate computational fluid dynamics algorithms and hypothesis.

Application of Long-Distance Forward-Scattering Particle Image Velocimetry in Micro-Scale Turbulent Jet Flow Tests

2006 ◽  
Author(s):  
Lichuan Gui ◽  
Bernard J. Jansen ◽  
John M. Seiner
Keyword(s):  
Particle Image Velocimetry ◽  
High Speed ◽  
Particle Image ◽  
Forward Scattering ◽  
Particle Image Velocimetry System ◽  
Central Plane ◽  
Long Distance ◽  
Micro Scale ◽  
Air Jet ◽  
Image Velocimetry

A new particle image velocimetry system is applied to measure turbulent air jet flows from a micro-scale nozzle. The applied MPIV system includes a long-distance microscope that enables not only a long working distance, but also a forward-scattering optical setup. By using a high repeating rate Nd:YAG laser and an advanced digital camera, particle image recordings can be captured at 60 fps, i.e. 30 PIV recording pairs per second, with an interframing time of 180 ns, so that a high-speed flow measurement is enabled in micro scale. Measurements were conducted in the central plane of an air jet from a nozzle of 500 μm in diameter at flow velocity up to 110 m/s. Mean velocity and Reynolds stress distributions were determined with statistical analyses of thousands of instantaneous velocity maps.

scholarly journals Development of the optical electronic setup for carrying out measurements by multicolor Particle Image Velocimetry

2021 ◽  
Vol 2127 (1) ◽  
pp. 012018
Author(s):  
S S Usmanova ◽  
N M Skornyakova ◽  
Yu S Belov ◽  
M V Sapronov ◽  
A V Kuchmenko ◽  
...  
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Computer Model ◽  
Vortex Structure ◽  
Test Object ◽  
3D Model ◽  
Particle Image ◽  
Velocity Fields ◽  
Laboratory Sample ◽  
Image Velocimetry

Abstract The paper is devoted to development of the optical electronic setup for carrying out measurements by multicolor particle image velocimetry. The main advantage of this method is the ability to visualize vector velocity fields in several planes simultaneously. As a result a 3D model of a setup was developed, a laboratory sample was assembled and series of testing experiments were performed. As a test object, vortex structure formed by a chemical stirrer in a cuvette with liquid has been considered. The experimental data were compared with the computer model developed in SolidWorks and FlowVision software.

Some Experience on Particle Image Velocimetry of Near-Wall Shear Layers at Subsonic Velocities

2010 ◽  
Vol 5 (2) ◽  
pp. 55-68
Author(s):  
Andrey V. Boiko Boiko ◽  
Vasily N. Gorev ◽  
Aleksandr V. Dovgal ◽  
Aleksandr M. Sorokin ◽  
Hein Stefan ◽  
...  
Keyword(s):  
Experimental Data ◽  
Particle Image Velocimetry ◽  
Particle Image ◽  
Shear Layers ◽  
Linear Instability ◽  
Wind Tunnel Testing ◽  
Mean Velocity ◽  
Separating Flow ◽  
Image Velocimetry ◽  
Near Wall

Experimental data on linear instability of the laminar separating flow and mean velocity characteristics of the turbulent boundary layer are reported. The results are obtained through wind-tunnel testing of Particle Image Velocimetry (PIV) performed at DLR, Goettingen. Details of the method, as applied to the above problems of fluid mechanics, are considered. The present findings seem helpful during experimental work on subsonic near-wall layers, when focusing on their instantaneous and time-mean velocity characteristics.

Experimental Measurements and Numerical Simulations in Isothermal Turbulent Flows

2012 ◽  
Author(s):  
Florin G. Florean ◽  
Jeni A. Popescu ◽  
Ionut Porumbel ◽  
Cristian Carlanescu ◽  
Gheorghe Dumitrascu
Keyword(s):  
Experimental Data ◽  
Numerical Simulation ◽  
Particle Image Velocimetry ◽  
Bluff Body ◽  
Particle Image ◽  
Experimental Measurements ◽  
Combustion System ◽  
Gas Generator ◽  
Turbine Engine ◽  
Image Velocimetry

The paper presents Particle Image Velocimetry experimental measurements and an ANSYS CFX numerical simulation of the mean and fluctuating velocity field in a turbulent, isothermal flow downstream of a V-shaped bluff body flame stabilizer equipping a post-combustion system installed downstream of a Garrett 30-67 gas turbine engine. The post-combustion system used as experimental model is described in detail, and the main characteristics of the Garrett 30-67 gas generator are included in the paper. Also, the instrumentation used on the experimental rig, including the Particle Image Velocimetry equipment, is briefly described. The presence of a bluff body inside the high speed flow creates a re-circulating wake structure, clearly seen in the experimental data. In the near field, the re-circulating region’s length and width of are captured reasonably well by the numerical simulation, but the momentum rate transfer further downstream is over-predicted, as the grid resolution worsens. An overall over prediction of the axial velocity by the numerical simulation is noted by comparing the numerical simulation results to the experimental data, explained by an over estimated inlet velocity in the numerical simulation, provided by Particle Image Velocimetry experimental measurements in the free exhaust jet behind the gas generator, without the installation of the post-combustion system, thus neglecting the effect of the latter on the operating regime of the gas turbine engine.

URANS Models for the Simulation of Full Load Pressure Surge in Francis Turbines Validated by Particle Image Velocimetry

2017 ◽  
Vol 139 (12) ◽  
Author(s):  
J. Decaix ◽  
A. Müller ◽  
A. Favrel ◽  
F. Avellan ◽  
C. Münch
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Electrical Power ◽  
Operating Conditions ◽  
Scale Model ◽  
Load Pressure ◽  
Vortex Rope ◽  
Full Load ◽  
Operating Range ◽  
Image Velocimetry

Due to the penetration of alternative renewable energies, the stabilization of the electrical power network relies on the off-design operation of turbines and pump-turbines in hydro-power plants. The occurrence of cavitation is however a common phenomenon at such operating conditions, often leading to critical flow instabilities which undercut the grid stabilizing capacity of the power plant. In order to predict and extend the stable operating range of hydraulic machines, a better understanding of the cavitating flows and mainly of the transition between stable and unstable flow regimes is required. In the case of Francis turbines operating at full load, an axisymmetric cavitation vortex rope develops at the runner outlet. The cavity may enter self-oscillation, with violent periodic pressure pulsations. The flow fluctuations lead to dangerous electrical power swings and mechanical vibrations, dictating an inconvenient and costly restriction of the operating range. The present paper reports an extensive numerical and experimental investigation on a reduced scale model of a Francis turbine at full load. For a given operating point, three pressure levels in the draft tube are considered, two of them featuring a stable flow configuration and one of them displaying a self-excited oscillation of the cavitation vortex rope. The velocity field is measured by two-dimensional (2D) particle image velocimetry (PIV) and systematically compared to the results of a simulation based on a homogeneous unsteady Reynolds-averaged Navier–Stokes (URANS) model. The validation of the numerical approach enables a first comprehensive analysis of the flow transition as well as an attempt to explain the onset mechanism.

Particle image velocimetry experiments on a macro-scale model for bacterial flagellar bundling

2004 ◽  
Vol 37 (6) ◽  
pp. 782-788 ◽  
Author(s):  
Min Jun Kim ◽  
Mun Ju Kim ◽  
James. C. Bird ◽  
Jinil Park ◽  
Thomas. R. Powers ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Scale Model ◽  
Image Velocimetry ◽  
Macro Scale
Sign in / Sign up

Export Citation Format

Share Document