Increasing the Accuracy of Measurements of Air Flow Velocity with an Acoustic Anemometer

The physical principles of the operation of an acoustic anemometer are considered. An improved model of the anemometer channel, which takes into account the thickness of the waveguide-air duct walls is described. The results of a calculation of the reflection coefficient of the open end of a waveguide with rectangular flanges for one of the normal modes when there is an air flow are presented. The acoustic pressure field on the wall of the anemometer channel is calculated and the effect of the wall thickness on the choice of the optimum acoustic anemometer parameters is estimated.