Studying the thermal effect in a swirled acoustic flow

Abstract

The mechanism of generation of acoustic oscillations associated with the formation of stable vortex structures in a moving medium is considered on the example of impact swirl flow. A self-regulation effect was detected for condition, when the limiting flow rate of a swirl flow has been reached. This effect is expressed in resonance amplification of the amplitude of the natural frequencies of the hydromechanical system due to the absorption of the component of the spectrum of acoustic oscillations generated by the vortex structure of the flow. A redistribution mechanism for the energy of an open system at resonance, associated with the influx of air from the external medium is considered. Temperature distributions on the lower surface of the obstacle were obtained using the thermal imager, and the energy losses associated with the flow cooling due to expansion were estimated.