Comparison of Particle Image Velocimetry and Laser Doppler Anemometry Measurements in Turbulent Fluid Flow

2000 ◽  
Vol 28 (11) ◽  
pp. 1393-1394 ◽  
Author(s):  
M. P. Wernet ◽  
A. Subramanian ◽  
H. Mu ◽  
J. R. Kadambi
Keyword(s):  
Particle Image Velocimetry ◽  
Fluid Flow ◽  
Particle Image ◽  
Laser Doppler Anemometry ◽  
Laser Doppler ◽  
Turbulent Fluid Flow ◽  
Turbulent Fluid ◽  
Image Velocimetry

Particle image velocimetry and laser Doppler anemometry experimental studies of a compressible short take-off and vertical landing ground vortex flow

2002 ◽  
Vol 216 (4) ◽  
pp. 171-187 ◽  
Author(s):  
N J Lawson ◽  
J M Eyles ◽  
K Knowles
Keyword(s):  
Particle Image Velocimetry ◽  
Vortex Flow ◽  
Particle Image ◽  
Laser Doppler Anemometry ◽  
Cross Flow ◽  
Laser Doppler ◽  
Data Set ◽  
Image Velocimetry ◽  
Vertical Landing ◽  
Dominant Frequencies

A particle image velocimetry (PIV) and laser Doppler anemometry (LDA) study of a scaled short take-off and vertical landing (STOVL) ground vortex flow is presented. The scaled flow features a compressible impinging jet in cross-flow with a moving ground plane. Mean and transient PIV and LDA velocity data are recorded from the ground vortex about the jet centre-line over a range of nozzle pressure ratios (NPR s) from 2.3 to 3.7, nozzle height—diameter ratios ( h/dn) from 3 to 10 (where dn = 12.7 mm) and cross-flow velocities (V∞) from 10 to 20 m/s, corresponding to effective velocity ratios of 19 < Ve−1 < 38. For each condition, 72 PIV vector maps were taken from the ground vortex region to generate an instantaneous and time-average data set. From the instantaneous data, a cinematic sequence was used to track the ground vortex position, which was found to fluctuate longitudinally by a root mean square distance of up to 4.47 dn and vertically by up to 2.18 dn. From the time-averaged PIV measurements, selected LDA pointwise data were taken at the average ground vortex core. Subsequent spectral analysis of the PIV time series showed the ground vortex position to fluctuate at dominant frequencies of between 2.5 and 5 Hz while the LDA data showed the velocity to fluctuate by dominant frequencies ranging between 1 and 30 Hz.

An Experimental Study of the Effect of Drag Reducing Additive on the Structure of Turbulence in Concentric Annular Pipe Flow Using Particle Image Velocimetry Technique

2013 ◽  
Author(s):  
Fabio Ernesto Rodriguez Corredor ◽  
Majid Bizhani ◽  
Ergun Kuru
Keyword(s):  
Particle Image Velocimetry ◽  
Fluid Flow ◽  
Pipe Flow ◽  
Particle Image ◽  
Polymer Concentration ◽  
Velocity Fluctuations ◽  
Polymer Fluid ◽  
Image Velocimetry ◽  
Drag Reducing Additive ◽  
Annular Pipe

The effect of drag reducing additive on the structure of turbulence in concentric annular pipe flow was investigated using Particle Image Velocimetry (PIV) technique. Experiments were conducted using a 9m long horizontal flow loop with concentric annular geometry (inner to outer pipe radius ratio = 0.4). The drag reducing additive was a commercially available partially hydrolyzed polyacrylamide (PHPA). The experiments were conducted using 0.1% V/V polymer concentration, giving a drag reduction of 26% at a solvent Reynolds number equal to 56400. Near wall local fluctuating velocity values were determined by analysing the PIV data. The root mean square (RMS) values of radial velocity fluctuations showed a significant decrease with the use of drag reducing additive. The RMS values of axial velocity fluctuations near the wall (Y+<10) were similar for both water and polymer fluid flow; though, higher peaks were obtained during the polymer fluid flow. As compared to water flow, a strong reduction in vorticity was observed during polymer fluid flow. The degree of vorticity reduction on the inner wall was higher than that of the outer wall. Results of the viscous dissipation and the shear production terms in the kinetic energy budget showed that less energy was produced and dissipated by the route of turbulence when using polymer fluid.

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