The ultrasonic doppler control of the inhomogeneous open liquid flow

The experimental and theoretical results obtained by complex (doppler and pulse) ultrasonic sounding of the open liquid flow is considered. The accuracy of the doppler measurements taking into account the inhomogeneous and depth of the liquid flow is estimated. Doppler signal, detected after scattering, has amplitude modulation which depends on phase inclusions (bubbles) concentration in the liquid and therefore the width of the doppler spectrum varies. Digital spectral processing of the ultrasonic signals allows to reduce a statistical error of the flow measurements. The analysis of spectral width gives us the possibility to determine the low level of the doppler flowmeter sensitivity and the application limits for traditional formulas for flow speed profile.