Turbulence Measurements Using the Laser Doppler Velocimeter

Although the laser Doppler velocimeter has been used for turbulence measurements in the past, no set of measurements in practical turbulent flows has been available to evaluate the instrument. In this work we examine in detail the photomultiplier signal representing the axial velocity of water within a glass pipe. We show that with proper analysis of the photomultiplier signal, the turbulent information that can be obtained in liquid flows is equivalent to recent hot-film studies. In shear flows the signal from the laser Doppler velocimeter contains additional information which may be related to the average shear