Analysis Of Acoustic Scattering Phenomena In Three-dimensional Eddy Current Fields In Different Containers

The application of acoustic treatment in liquid has a history of nearly 100 years,but the large-scale application is still less.The reason why is that the acoustic cavitation activity mainly concentrated on the vicinity of the transducer and the formation of standing waves in the sonochemical reactor leading to the low efficiency of large-scale application.When a f eely moving plane wave encounters a vortex field,the sound wave will be scattered.In addition to the original plane wave,there exists scattering waves around the vortex.The two kinds of sound waves will superpose to form a total sound field.As a result,the standing wave in the sonochemical reactor is reduced.In this paper,Comsol Multiphysics is used to simulate phenomenons of a three-dimensional vortex field scattered on sound wave in different vessels,and the scattering sound field is analyzed.The following conclusions are obtained:1.When the background flow field is a three-dimensional Oseen vortex field,the shape of reactors have an obvious influence on the scattering sound field.Different reactors have a different scattering sound field and the scattering situation on different positions in the same container is also different.Near the vortex center the scattering sound pressure is larger and the directivity is stronger than the position far away from the vortex center.2.When the background flow field is a three-dimensional Oseen vortex field,the scattering sound field in each reactor is completely different at different times.The scattering sound field in cylindrical vessel is less affected by time,and mainly concentrates in the upper of the vessel.The conical vessel takes the second place,and has an effect on the scattering sound field in the whole container,which makes it more uniform and chaotic.The scattering sound pressure of the upper is greater than that of the lower part of the vessel.In spherical vessel,the scattering sound field changes most violent with the advance of time,and the scattering sound field is distributed uniformly finally.3.When the background flow field is a three-dimensional Oseen vortex field,the Mach number also has a great effect on the scattering sound field in the reactor.In the vortex center section,the scattering sound pressure increases obviously with the increase of Mach number,and the directivity increases also obviously.In the region far from the vortex center,the scattering sound pressure gradually increases with the increase of Mach number,but the directivity gradually decreases with the increase of Mach number.And there are several scattering peaks,which makes the sound field more complex.4.When the background flow field is a three-dimensional tornado funnel vortex field,the scattering of the sound wave by the tornado vortex field is still closely related to the shape of the vessel.The scattering sound field becomes more complex away from the center axis.However,in the tornado funnel vortex field,the scattering sound pressure value gets greater away from the center axis.5.When the background flow field is a three-dimensional swirl field of tornado funnel,the distribution of scattering sound field in the reactor becomes more and more complex and uniform with the advance of time.