scholarly journals Fluid Dynamic Assessment of Three Polymeric Heart Valves Using Particle Image Velocimetry

2006 ◽  
Vol 34 (6) ◽  
pp. 936-952 ◽  
Author(s):  
Hwa Liang Leo ◽  
Lakshmi Prasad Dasi ◽  
Josie Carberry ◽  
Hélène A. Simon ◽  
Ajit P. Yoganathan
Keyword(s):  
Particle Image Velocimetry ◽  
Heart Valves ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Dynamic Assessment ◽  
Image Velocimetry

An Experimental Study on the Performance of Drag-Reducing Polymers in Single- and Multiphase Horizontal Flow Using Particle Image Velocimetry

2018 ◽  
Vol 140 (5) ◽  
Author(s):  
Ihab H. Alsurakji ◽  
A. Al-Sarkhi ◽  
M. Habib ◽  
Hassan M. Badr
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Pipe Wall ◽  
Fluid Dynamic ◽  
Water Soluble ◽  
Experimental Investigations ◽  
Two Phase ◽  
Image Velocimetry ◽  
Flow Field Characteristics ◽  
Phase Water

This paper presents experimental investigations conducted to understand the influence of water-soluble drag-reducing polymers (DRPs) in single- and two-phase (stratified wavy) flow on flow-field characteristics. These experiments have been presented for water and air–water flowing in a horizontal polyvinyl chloride 22.5-mm ID, 8.33-m long pipe. The effects of liquid flow rates and DRP concentrations on streamlines and the instantaneous velocity were investigated by using particle image velocimetry (PIV) technique. A comparison of the PIV results was performed by comparing them with the computational results obtained by fluent software. One of the comparisons has been done between the PIV results, where a turbulent flow with DRP was examined, and the laminar–computational fluid dynamic (CFD) prediction. An agreement was found in the region near the pipe wall in some cases. The results showed the powerfulness of using the PIV techniques in understanding the mechanism of DRP in single- and two-phase flow especially at the regions near the pipe wall and near the phases interface. The results of this study indicate that an increase in DRP concentrations results in an increase in drag reduction up to 45% in single-phase water flow and up to 42% in air–water stratified flow.

Particle Image Velocimetry Used to Qualitatively Validate Computational Fluid Dynamic Simulations in an Oxygenator: A Proof of Concept

2015 ◽  
Vol 6 (3) ◽  
pp. 340-351 ◽  
Author(s):  
Peter C. Schlanstein ◽  
Felix Hesselmann ◽  
Sebastian V. Jansen ◽  
Jeannine Gemsa ◽  
Tim A. Kaufmann ◽  
...  
Keyword(s):  
Particle Image Velocimetry ◽  
Computational Fluid Dynamic ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Proof Of Concept ◽  
Dynamic Simulations ◽  
Image Velocimetry

Particle Image Velocimetry Measurements in a Representative Gas-Cooled Prismatic Reactor Core Model: Distribution of Flow From the Upper Plenum to the Fuel Block Arrangement

2013 ◽  
Author(s):  
Thomas E. Conder ◽  
Ralph S. Budwig ◽  
Richard S. Skifton
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Fluid Dynamic ◽  
National Laboratory ◽  
Reactor Core ◽  
Flow Distribution ◽  
Flow Rates ◽  
Image Velocimetry ◽  
Direct Support ◽  
Block Arrangement

An experiment was conducted at Idaho National Laboratory to investigate the bypass flow associated with a Gas Turbine-Modular Helium Reactor in direct support of Computational Fluid Dynamic validation [1]. Velocity fields within a representative quartz model, consisting of an upper plenum, upper block, and lower block, were measured using Particle Image Velocimetry; after which, flow rates were calculated in each section. The present study was carried out to determine flow distribution from the upper plenum to the fuel block assembly. It was found that the flow rates in the lower six coolant channels varied from their average only by 2.4, 4.6, and 2.5% for the low, medium, and high flow cases, respectively. Consequently, it was concluded that the non-uniform inlet velocity condition in the upper plenum had insignificant effect on flow distribution to the coolant channels and interstitial gap.

Flow Structures in a U-Shaped Fuel Cell Flow Channel: Quantitative Visualization Using Particle Image Velocimetry

2004 ◽  
Vol 2 (1) ◽  
pp. 70-80 ◽  
Author(s):  
J. Martin ◽  
P. Oshkai ◽  
N. Djilali
Keyword(s):  
Particle Image Velocimetry ◽  
Fuel Cell ◽  
Cross Sections ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Vortex Formation ◽  
Image Velocimetry ◽  
Quantitative Visualization ◽  
Image Density ◽  
Transport Channels

Flow through an experimental model of a U-shaped fuel cell channel is used to investigate the fluid dynamic phenomena that occur within serpentine reactant transport channels of fuel cells. Achieving effective mixing within these channels can significantly improve the performance of the fuel cell and proper understanding and characterization of the underlying fluid dynamics is required. Classes of vortex formation within a U-shaped channel of square cross section are characterized using high-image-density particle image velocimetry. A range of Reynolds numbers, 109⩽Re⩽872, corresponding to flow rates encountered in a fuel cell operating at low to medium current densities is investigated. The flow fields corresponding to two perpendicular cross sections of the channel are characterized in terms of the instantaneous and time-averaged representations of the velocity, streamline topology, and vorticity contours. The critical Reynolds number necessary for the onset of instability is determined, and the two perpendicular flow planes are compared in terms of absolute and averaged velocity values as well as Reynolds stress correlations. Generally, the flow undergoes a transition to a different regime when two recirculation zones, which originally develop in the U-bend region, merge into one separation region. This transition corresponds to generation of additional vortices in the secondary flow plane.

Particle Image Velocimetry Measurement and Computational Fluid Dynamic Simulations of the Unsteady Flow Within a Rotating Disk Cavity

2014 ◽  
Vol 136 (11) ◽  
Author(s):  
Xiang Luo ◽  
Dongdong Liu ◽  
Hongwei Wu ◽  
Zhi Tao
Keyword(s):  
Particle Image Velocimetry ◽  
Computational Fluid Dynamic ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Three Dimensional ◽  
Rotating Disk ◽  
Turbine Rotor ◽  
Dynamic Simulations ◽  
Image Velocimetry ◽  
The Impact

In this article a combined experimental and numerical investigation of the unsteady mixing flow of the ingestion gas and rim sealing air inside a rotating disk cavity was carried out. A new test rig was set up, and the experiments were conducted on a 1.5-stage turbine rotor disk and included pressure measurements. The flow structure of the mixing region of the ingestion gas and sealing air in cavity was measured using the particle image velocimetry (PIV) technique. To complement the experimental investigation and to aid in understanding the flow mechanism within the cavity, a three-dimensional (3D) unsteady computational fluid dynamic (CFD) analysis was undertaken. Both simulated and experimental results indicated that near the rotating disk, (i) a large amount of the ingestion gas will turn around and flow out the cavity due to the impact of the centrifugal force and the Coriolis force, (ii) a small amount of ingestion gas will mix transiently with the sealing air inside the cavity, whereas near the static disk, (iii) the ingestion gas will flow into the cavity along the static wall and mix with the sealing air.

scholarly journals Particle Image Velocimetry Measurements in a Representative Gas-Cooled Prismatic Reactor Core Model: Flow in the Coolant Channels and Interstitial Bypass Gaps

2012 ◽  
Author(s):  
Thomas E. Conder ◽  
Richard S. Skifton ◽  
Ralph S. Budwig
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Fluid Dynamic ◽  
Reactor Core ◽  
Index Of Refraction ◽  
Bypass Flow ◽  
Model Flow ◽  
Image Velocimetry ◽  
Key Issues ◽  
Representative Model

Core bypass flow is one of the key issues with the prismatic Gas Turbine-Modular Helium Reactor, and it refers to the coolant that navigates through the interstitial passages between the graphite fuel blocks instead of traveling through the designated coolant channels. To determine the bypass flow, a double scale representative model was manufactured and installed in the Matched Index-of-Refraction flow facility; after which, stereo Particle Image Velocimetry (PIV) was employed to measure the flow field within. PIV images were analyzed to produce vector maps, and flow rates were calculated by numerically integrating the velocity field. It was found that the bypass flow varied between 6.9–15.8% for channel Reynolds numbers of 1,746 and 4,618 with a 6mm gap. The results were compared to computational fluid dynamic (CFD) pre-test simulations. When compared to these pretest calculations, the CFD analysis appeared to under predict the flow through the gap.

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