scholarly journals Possible Limitations of the Particle Image Velocimetry Method in the Presence of Strong Electric Fields

Processes ◽  
2021 ◽  
Vol 9 (10) ◽  
pp. 1790
Author(s):  
Michal Malík ◽  
Jiří Primas ◽  
Petr Schovanec ◽  
Josef Novák ◽  
Pavel Pokorný ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Electric Fields ◽  
Particle Image ◽  
Negative Influence ◽  
Piv Method ◽  
Tracer Particles ◽  
Piv Measurement ◽  
Image Velocimetry ◽  
Measurement Results ◽  
Strong Electric Fields

While examining the airflow generated between the asymmetrical electrodes connected to high voltage, the authors investigated the possible limitations of the particle image velocimetry (PIV) method in the presence of strong electric fields. The tracer particles used in the PIV method in these conditions are affected by electromagnetic forces; therefore, it is necessary to determine whether these forces have any non-negligible negative influence on the measurement results. For this purpose, the authors theoretically analyzed all the possible forces and measured the generated airflow using PIV and constant temperature anemometry methods. The experimental and theoretical results clearly show the viability of the PIV measurement method even in these very specific conditions.

Comparison Between PIV Results and CFD Simulations of Air Flows in a Thin Electronics Casing Model

2012 ◽  
Author(s):  
Masaru Ishizuka ◽  
Tomoyuki Hatakeyama ◽  
Risako Kibushi ◽  
Yasushi Nishino ◽  
Shinji Nakagawa
Keyword(s):  
Fluid Dynamics ◽  
Particle Image Velocimetry ◽  
Particle Image ◽  
Electronic Equipment ◽  
Cfd Simulations ◽  
Cooling Performance ◽  
Piv Measurement ◽  
Image Velocimetry ◽  
Measurement Results ◽  
Good Agreement

The aim of this study was to acquire benchmark test data for simulating computational fluid dynamics in thin electronic equipment. Flow in the model of thin electronic equipment was measured by using particle image velocimetry PIV). Dummy components were placed in the model and their configurations altered. The temperature rise of a heat source in the model was also measured and the cooling performance examined. The PIV measurement results revealed the changes in flow with changes in the configuration of the components. Comparison of the experimental results with numerical results showed good agreement in terms of the overall velocity field.

scholarly journals Measurement of Air Flow Outside a Burning Cigarette during a Puff using Particle Image Velocimetry

2004 ◽  
Vol 21 (4) ◽  
pp. 216-222
Author(s):  
A Nagao ◽  
K Miura ◽  
S Kitao ◽  
M Horio
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Air Flow ◽  
Maximum Velocity ◽  
Flow Distribution ◽  
Combustion Mechanism ◽  
Air Flow Rate ◽  
Tracer Particles ◽  
Image Velocimetry ◽  
Cigarette Paper

AbstractIn order to clarify the mechanism for the generation of cigarette smoke, the combustion mechanism of a burning cigarette during a puff was investigated by focusing on air transfer. In particular, the air flow distribution outside a burning cigarette was observed and related to the aerodynamic effects of the cigarette paper and the puffing rate. The air flow rate was measured by Particle Image Velocimetry (PIV), using olive oil droplets as the tracer particles. It was found that air does not flow into the tip of the burning cigarette and that the air flow was concentrated at the region -2 to 2 mm around the cigarette paper char-line. This behavior was independent of the cigarette paper basis weight. When the puffing rate was changed from 2.5 to 35 mL/s, the air flow was concentrated at a region close to the cigarette paper char-line and the maximum velocity around the cigarette paper char-line increased with the puffing rate.

A Method of Measuring Turbulent Flow Structures With Particle Image Velocimetry and Incorporating Into Boundary Conditions of Large Eddy Simulations

2018 ◽  
Vol 140 (7) ◽  
Author(s):  
Puxuan Li ◽  
Steve J. Eckels ◽  
Garrett W. Mann ◽  
Ning Zhang
Keyword(s):  
Particle Image Velocimetry ◽  
Large Eddy Simulation ◽  
Boundary Conditions ◽  
Particle Image ◽  
Advantages And Disadvantages ◽  
Eddy Simulation ◽  
Piv Measurement ◽  
Image Velocimetry ◽  
Large Eddy ◽  
Inlet Conditions

The setup of inlet conditions for a large eddy simulation (LES) is a complex and important problem. Normally, there are two methods to generate the inlet conditions for LES, i.e., synthesized turbulence methods and precursor simulation methods. This study presents a new method for determining inlet boundary conditions of LES using particle image velocimetry (PIV). LES shows sensitivity to inlet boundary conditions in the developing region, and this effect can even extend into the fully developed region of the flow. Two kinds of boundary conditions generated from PIV data, i.e., steady spatial distributed inlet (SSDI) and unsteady spatial distributed inlet (USDI), are studied. PIV provides valuable field measurement, but special care is needed to estimate turbulent kinetic energy and turbulent dissipation rate for SSDI. Correlation coefficients are used to analyze the autocorrelation of the PIV data. Different boundary conditions have different influences on LES, and their advantages and disadvantages for turbulence prediction and static pressure prediction are discussed in the paper. Two kinds of LES with different subgrid turbulence models are evaluated: namely dynamic Smagorinsky–Lilly model (Lilly model) and wall modeled large eddy simulation (WMLES model). The performances of these models for flow prediction in a square duct are presented. Furthermore, the LES results are compared with PIV measurement results and Reynolds-stress model (RSM) results at a downstream location for validation.

scholarly journals Data assimilation method to de-noise and de-filter particle image velocimetry data

2019 ◽  
Vol 877 ◽  
pp. 196-213 ◽  
Author(s):  
Jurriaan J. J. Gillissen ◽  
Roland Bouffanais ◽  
Dick K. P. Yue
Keyword(s):  
Particle Image Velocimetry ◽  
Data Assimilation ◽  
Particle Image ◽  
Particle Image Velocimetry Data ◽  
Reconstruction Error ◽  
Integration Time ◽  
Piv Measurement ◽  
Image Velocimetry ◽  
The Difference ◽  
Filter Particle

We present a variational data assimilation method in order to improve the accuracy of velocity fields $\tilde{\boldsymbol{v}}$, that are measured using particle image velocimetry (PIV). The method minimises the space–time integral of the difference between the reconstruction $\boldsymbol{u}$ and $\tilde{\boldsymbol{v}}$, under the constraint, that $\boldsymbol{u}$ satisfies conservation of mass and momentum. We apply the method to synthetic velocimetry data, in a two-dimensional turbulent flow, where realistic PIV noise is generated by computationally mimicking the PIV measurement process. The method performs optimally when the assimilation integration time is of the order of the flow correlation time. We interpret these results by comparing them to one-dimensional diffusion and advection problems, for which we derive analytical expressions for the reconstruction error.

Flow Field Analysis of Dielectrophoretically-Suspended Particles

2007 ◽  
Author(s):  
Stuart J. Williams ◽  
Steven T. Wereley
Keyword(s):  
Electric Fields ◽  
Particle Image ◽  
Fluid Velocity ◽  
Microfluidic Channel ◽  
Velocity Fields ◽  
Field Analysis ◽  
Tracer Particles ◽  
Image Velocimetry ◽  
Flow Field Analysis ◽  
Complete Investigation

Understanding the fluid dynamics around a particle in suspension is important for a complete investigation of many hydrodynamic phenomena, including microfluidic models. A novel tool that has been used to analyze fluid velocity fields in microfluidics is micro-resolution particle image velocimetry (μPIV) [1]. Dielectrophoresis (DEP) is a technique that can translate and trap particles by induced polarization in the presence of nonuniform electric fields. In this paper, DEP has been used to capture and suspend a single 10.1μm diameter spherical particle in a microfluidic channel. μPIV is then used with smaller tracer particles (0.5μm) to investigate the hydrodynamics of fluid flow past the trapped particle.

Hydrodynamic Investigations of a Dielectrophoretically Trapped and Agitated Microparticle

2009 ◽  
Author(s):  
Stuart J. Williams ◽  
Steven T. Wereley
Keyword(s):  
Fluid Dynamics ◽  
Particle Image Velocimetry ◽  
Spherical Particle ◽  
Electric Fields ◽  
Particle Image ◽  
Suspended Particle ◽  
Microfluidic Channel ◽  
Induced Polarization ◽  
Image Velocimetry ◽  
Complete Investigation

Understanding the fluid dynamics of a particle in suspension is important for a complete investigation of many hydrodynamic phenomena, including microfluidic models. Dielectrophoresis (DEP) is a technique that can translate and trap particles through induced polarization when in the presence of non-uniform electric fields. Here, DEP has been used to capture and suspend a single 10.1 μm diameter spherical particle in a microfluidic channel. Procedures and results for controlled, oscillatory dielectrophoretic agitation of the suspended particle are shown. Hydrodynamic investigations are discussed including the incorporation of micron-resolution particle image velocimetry (μPIV).

scholarly journals Application of particle image velocimetry (PIV) to measure the displacement of sandy soil in laboratory

2021 ◽  
Vol 63 (3) ◽  
pp. 70-77
Keyword(s):  
Grain Size ◽  
Particle Image Velocimetry ◽  
Sandy Soil ◽  
Laboratory Tests ◽  
Particle Image ◽  
Degree Of Saturation ◽  
Grain Sizes ◽  
Piv Method ◽  
Soil Displacement ◽  
Image Velocimetry

Particle image velocimetry (PIV) has been heavily used to measure the displacement and flow velocity in fluid mechanics. However, applications of this method to determining soil displacement in geotechnical laboratory tests are rare. This paper aims to verify the applicability of this method in determining the displacement of sandy soil under different saturation conditions and soil grain sizes. The results showed that this method could effectively determine soil displacement with an accuracy of 0.13 mm. Furthermore, the degree of saturation of soil did not influence the PIV results whereas the homogeneity of soil, as indicated by grain size distribution, reduced the precision of the PIV method.

Development of 3-D Printed Optically Clear Rigid Anatomical Vessels for Particle Image Velocimetry Analysis in Cardiovascular Flow

2019 ◽  
Author(s):  
Nicholas Stanley ◽  
Ashley Ciero ◽  
William Timms ◽  
Rodward L. Hewlin
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Flow Analysis ◽  
Index Of Refraction ◽  
Working Fluid ◽  
Post Processing ◽  
Anatomical Models ◽  
Tracer Particles ◽  
Image Velocimetry ◽  
Flow Tracer

Abstract In recent years, blood flow analysis of diseased arterial mock vessels using particle image velocimetry (PIV) has been hampered by the inability to fabricate optically clear anatomical vessel models that realistically replicate the complex morphology of arterial vessels and provide highly resolved flow images of flow tracer particles. The aim of the present work is to introduce an approach for producing optically clear rigid anatomical models that are suitable for PIV analysis using a common 3-D SLA inkjet printing process (using a Formlabs Form 2 3-D printer) and stock clear resin (RS-F2-GPCL-04). By matching the index of refraction (IOR) of the working fluid to the stock clear resin material, and by printing the part in a 45-degree print orientation, a clear anatomical model that allows clear visualization of flow tracer particles can be produced which yields highly resolved flow images for PIV analyses. However, a 45-degree print orientation increases the need for post processing due to an increased amount of printed support material. During post processing, the part must be wet sanded in several steps and surface finished with Novus Plastic Polish 3 Step System to achieve the final surface finish needed to yield high quality flow images. The fabrication methodology of the clear anatomical models is described in detail.

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