Optical Doppler method for investigating turbulent flow by spectral analysis of a signal

A method for determining the parameters of turbulent flow of a gas or liquid from the energy spectrum of a signal obtained in an optical Doppler velocity meter is described. An analysis is made of the limits of validity of a method suggested for measuring the distribution of the local velocity density. Apparatus is described and the results are given of measurements of the average velocity and intensity of turbulence in an axisymmetic submerged water stream of initially small diameter.