The Scattering Characteristics Of Two-dimensional Plane Acoustic Waves In The Oseen Vortex Field

The traditional phonochemical reactor is easy to generate standing wave sound field,which is not conducive to improving the efficiency of processing.The method commonly used to eliminate the standing wave sound field in the sonochemical reactor is to change the sound field distribution in the reactor from the sound wave radiation method,but it is mostly used in small acoustic chemical reactors.lt is also possible to increase the transducer method to improve the processing effect,but it causes a certain waste of resources.In this paper,staggered-grid finite-difference time-domain(FDTD)method and absorption boundary are used to solve the acoustic perturbation equation,which simulates the propagation characteristics of sound in vortex field and multiple vortex fields.It can be used to improve the sound field distribution in a phonochemical reactor and eliminate the standing wave sound field.The results have shown that:1.The direction of the sound wave after it passes through the vortex field is related to the direction of the vortex.When the vortex rotates in the clockwise direction,the sound wave is deflected downward under the action of the vortex.When the vortex is rotated counterclockwise,the sound waves are deflected upward.The deflection angle of the acoustic wave increases as the Mach number increases,and is finally scattered in all directions.2.When the background vortex field is a counter-rotating vortex pair,the effect of the vortex field on the acoustic wave changes with the incident angle.When two vortices are arranged horizontally with respect to the incident acoustic wave,the reverse vortex minimizes the scattering of sound waves by the flow field.When the two vortices are arranged vertically with respect to the incident sound wave,the counter-rotating vortex pair has the largest scattering effect on the sound wave and has more directivity.When the upper vortex rotates in the counterclockwise direction and the lower vortex rotates in the clockwise direction,the sound pressure between the two vortices decreases,and the upper and lower parts of the two vortices increase in sound pressure.When the upper vortex rotates in the clockwise direction and the lower vortex rotates in the counterclockwise direction,the sound pressure between the two vortexes increases with each other,and the sound pressure amplitude also increases.3.When the background vortex field is a co-rotating vortex pair,the vortex field has almost the same scattering effect on sound waves at different incident angles,but the scattering effect is stronger than the counter-rotating vortex pair.The scattering effect of the co-occurrence vortex pair on the sound wave gradually decreases as the distance between the two vortices increases.Therefore,we can increase the number of vortices in the sonochemical inverter so that the vortices rotate in the same direction and are aligned perpendicular to the direction of the incident wave,which scatter the sound waves in all directions to eliminate the standing wave sound field.