Improving SNR of Doppler signal and expanding dynamic measurement range of single-mode VCSEL self-mixing laser Doppler velocimetry

2005 ◽  
Author(s):  
Jun Xu ◽  
Deyong He ◽  
Liang Lv ◽  
Huaqiao Gui ◽  
Tianpeng Zhao ◽  
...  
Keyword(s):  
Laser Doppler Velocimetry ◽  
Single Mode ◽  
Dynamic Measurement ◽  
Measurement Range ◽  
Laser Doppler ◽  
Doppler Signal ◽  
Doppler Velocimetry

Laser Doppler Velocimetry Signal Processing Based on Spectral Refinement and Correction

2011 ◽  
Vol 383-390 ◽  
pp. 6319-6323
Author(s):  
Nian Long Song ◽  
Da Zhang ◽  
Qi Li
Keyword(s):  
Signal Processing ◽  
Laser Doppler Velocimetry ◽  
Operation Time ◽  
Laser Doppler ◽  
Doppler Signal ◽  
Doppler Velocimetry ◽  
Basic Principles ◽  
Doppler Signals ◽  
Sinusoidal Signals ◽  
Ratio Correction

In order to improve the accuracy of signal processing in Laser Doppler Velocimetry, a method based on the association of spectral refinement and correction is presented. Zoom-FFT and ratio correction are adopted to realize this method. Basic principles of zoom-FFT and ratio correction are expounded. FFT and the method are adopted to process sinusoidal signals and simulated laser Doppler signals with different frequencies separately in circumstance of MATLAB 7.0. Comparisons between the results of FFT and the method are carried out. The comparisons show that this method has the capability to improve the accuracy of laser Doppler signal processing significantly and the operation time is acceptable for LDV system.

scholarly journals Investigation of Internal Flow in Centrifugal Pump Diffuser using Laser Doppler Velocimetry (LDV) and Computational Fluid Dynamics

2021 ◽  
Vol 1909 (1) ◽  
pp. 012075
Author(s):  
Daisuke Sugiyama ◽  
Asuma Ichinose ◽  
Tomoki Takeda ◽  
Kazuyoshi Miyagawa ◽  
Hideyo Negishi ◽  
...  
Keyword(s):  
Fluid Dynamics ◽  
Computational Fluid Dynamics ◽  
Centrifugal Pump ◽  
Laser Doppler Velocimetry ◽  
Internal Flow ◽  
Laser Doppler ◽  
Doppler Velocimetry

scholarly journals Laser-Doppler Velocimetry Measurements Inside a Backward Curved Centrifugal Fan

2001 ◽  
Vol 7 (3) ◽  
pp. 173-181
Author(s):  
Tong-Miin Liou ◽  
Meng-Yu Chen
Keyword(s):  
Flow Rate ◽  
Turbulence Intensity ◽  
Laser Doppler Velocimetry ◽  
Reverse Flow ◽  
Flow Region ◽  
Design Flow ◽  
Laser Doppler ◽  
Centrifugal Fan ◽  
Doppler Velocimetry ◽  
Flow Rates

Laser-Doppler velocimetry (LDV) measurements are presented of relative mean velocity and turbulence intensity components inside the impeller passage of a centrifugal fan with twelve backward curved blades at design, under-design, and over-design flow rates. Additional LDV measurements were also performed at the volute outlet to examine the uniformity of the outlet flow for the three selected flow rates. Complementary flow visualization results in the tongue region are further presented. It is found that the number of characteristic flow regions and the average turbulence level increase with decreasing air flow rate. For the case of under-design flow rate, there are a through-flow region on the suction side, a reverse flow region on the pressure side, and a shear layer region in between. The corresponding average turbulence intensity is as high as 9.1% of blade tip velocity.

scholarly journals Imaging laser Doppler velocimetry

2011 ◽  
Vol 52 (4) ◽  
pp. 1017-1026 ◽  
Author(s):  
Alexander H. Meier ◽  
Thomas Roesgen
Keyword(s):  
Laser Doppler Velocimetry ◽  
Laser Doppler ◽  
Doppler Velocimetry
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