Spatial resolution sufficient for calculation of vorticity.In laser-speckle velocimetry, pulsed or chopped laser beam expanded in one dimension by cylindrical lens to illuminate thin, fan-shaped region of flow measured. Flow seeded by small particles. Lens with optical axis perpendicular to illuminating beam forms image of illuminated particles on photographic plate. Speckle pattern of laser-illuminiated, seeded flow recorded in multiple-exposure photographs and processed to extract data on velocity field. Technique suited for study of vortical flows like those about helicopter rotor blades or airplane wings at high angles of attack.
Measuring Flow With Laser-Speckle Velocimetry
NASA Tech Briefs ; 12 , 9
1988-10-01
Miscellaneous
No indication
English
Digital Correlation In Laser-Speckle Velocimetry
NTRS | 1992
|The Reduction of Laser Speckle Noise in Planar Doppler Velocimetry Systems
British Library Conference Proceedings | 1998
|