An Approximate Mathematical Model of Ultrasonic Wave Modulated by Von Karman Vortex Street in a Liquid Fluid

摘要

It is known that both phase and amplitude of an ultrasonic wave passing through Von Karman vortex street perpendicular on the bluff body axis, are modulated. Modulation is result of natural fluid flow in the Von Karman vortex street, absorption and dispersion of ultrasonic wave. This paper is intended to present influence of vortex shedding on the amplitude modulation of ultrasonic wave which is caused by movement of vortices in vortex street. Mathematical model of the amplitude modulation of ultrasonic wave in Von Karman street and influence of ultrasonic wave absorption in vortices on the amplitude modulation have also been presented. Experimental results of testing prototype based on amplitude modulation developed for this research, and comparative analysis with result of vortex meter prototype based on phase modulation of ultrasonic wave have been done also. Test results obtained on a vortex meter prototype based on amplitude modulation, developed for this research and comparative analysis of these results and results obtained on a vortex meter prototype based on phase modulation of ultrasonic wave have been presented in the paper.