A Comparison of Four Velocity Bias Correction Techniques in Laser Doppler Velocimetry

Abstract

Data from a two-component dual-beam laser-Doppler Velocimeter were used to evaluate four different velocity bias correction methods. The data were collected over a range of valid data rates from 100 Hz to 20 kHz at four flow locations in a shear layer. Turbulence intensities ranged from 15 to 100 percent. Flow statistics were calculated using these proposed velocity bias correction techniques. The results were compared to the unbiased values, which were obtained using an approximated equal-time sampling technique. Some of the correction schemes performed well at low turbulence levels, but became ineffective at high turbulence levels. One ad hoc empirical correction scheme showed relatively good results throughout.