Cinematographic system for high-image-density particle image velocimetry

1994 ◽  
Vol 17 (1-2) ◽  
pp. 110-114 ◽  
Author(s):  
J. C. Lin ◽  
D. Rockwell
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Image Velocimetry ◽  
Image Density

Effect of inlet port on the flow in the cylinder of an internal combustion engine

2006 ◽  
Vol 220 (1) ◽  
pp. 73-82 ◽  
Author(s):  
A Yasar ◽  
B Sahin ◽  
H Akilli ◽  
K Aydin
Keyword(s):  
Particle Image Velocimetry ◽  
Velocity Distribution ◽  
Particle Image ◽  
Combustion Engine ◽  
Flow Characteristics ◽  
Intake Port ◽  
Intake Valve ◽  
Piv Technique ◽  
Image Velocimetry ◽  
Image Density

In this study, the characteristics of flow emerging from the inlet of the intake port in the cylinder were investigated experimentally. A particle image velocimetry (PIV) technique was used to measure the velocity distribution in order to observe and analyse the flow behaviour. High-image-density PIV provided acquisition of patterns of instantaneous and averaged vorticity and velocity, revealing the detail of the flow characteristics in the cylinder cavity. With this measuring technique, it is possible to study the effect of intake valve geometry on the flow behaviours. The results showed that the flow structure changed substantially along the cylinder stroke due to the geometry of the intake valve port.

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.

High image-density particle image velocimetry using laser scanning techniques

1993 ◽  
Vol 14 (3) ◽  
pp. 181-192 ◽  
Author(s):  
D. Rockwell ◽  
C. Magness ◽  
J. Towfighi ◽  
O. Akin ◽  
T. Corcoran
Keyword(s):  
Particle Image Velocimetry ◽  
Laser Scanning ◽  
Particle Image ◽  
Image Velocimetry ◽  
Image Density

Flow Structure in a Radial Flow Pumping System Using High-Image-Density Particle Image Velocimetry

1994 ◽  
Vol 116 (3) ◽  
pp. 538-544 ◽  
Author(s):  
O. Akin ◽  
D. Rockwell
Keyword(s):  
Particle Image Velocimetry ◽  
Particle Image ◽  
Substantial Reduction ◽  
Source Terms ◽  
Ensemble Averaging ◽  
Pressure Source ◽  
Pumping System ◽  
Image Velocimetry ◽  
Image Density ◽  
Instantaneous Pressure

Use of high-image-density particle image velocimetry (PIV) allows characterization of the instantaneous structure of wake and wake-blade interactions in a simulated rotating machine. The distribution of vorticity over an entire plane within the pumping system is related to the instantaneous pressure source terms in the wake of the impeller. Comparison of instantaneous and ensemble-averaged vorticity contours shows that limited ensemble-averaging can produce a substantial reduction in vorticity levels associated with the instantaneous pressure source terms. When the wake from the impeller interacts with a stationary diffuser blade, the instantaneous processes of flow separation and reattachment can be effectively characterized using combinations of instantaneous streamline patterns and contours of constant vorticity. Moreover, active control of the inflow into the pumping system allows substantial modification of these vorticity distributions.

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