Study On Cavitation Characteristics Of Hydraulic Cavitators Based On Different Structures

Along with the rapid development of modern industry,the sewage generated also intensifies environmental pollution.Effective treatment of wastewater and its ability to recycle are important for promoting sustainable social development and alleviating water shortages.Countries around the world attach great importance to sewage treatment and actively explore new methods and processes for wastewater treatment.At present,the hydrodynamic cavitation technology with clean,low energy consumption and high cost as a new type of sewage treatment technology has attracted much attention and has become a hot spot in academic and engineering circles at home and abroad.This paper is based on the principle of hydrodynamic cavitation,based on the characteristics of venturi and damper,the Fluent simulation software is used to simulate the hydrodynamic cavitation process of venturi cavitation and squirt cavitation,and The gas content rate is used as the basis for judging the strength of the cavitation effect.The cavitation effect under different parameters was simulated and analyzed,and the related laws affecting the cavitation effect of the cavitation were explored.The research conclusions are as follows:(1)The inlet pressure plays a decisive role in the cavitation intensity of the venturi cavitation and the choking cavitation.Increasing the pressure gradient in the inlet pressure cavitation increases,indicating that the cavitation effect is better as the inlet pressure increases.(2)The throat diameter and inlet angle of the venturi are changed.When the throat gas diameter is in the range of 10 mm to 16 mm,the void fraction increasesgradually with the increase of the throat diameter,at a diameter of 14 mm,the void fraction reaches a maximum.And the venturi tube has the best cavitation effect when the inlet angle is 50°and the throat diameter is 14 mm.(3)The inlet diameter has a decisive influence on the cavitation effect of the cavitation.The inlet diameter of the venture tube is too small,which is not conducive to the collapse of cavitation;when the inlet diameter is too large,the void fraction is low,the degree of cavitation is low and the kinetic energy loss is too large.The cavitation effect of the venturi tube cavitation achieves the best effect when the inlet diameter is 50 mm.As the inlet diameter of the choking cavitation increases,the value of the maximum void fraction in the choking tube also increases,which can generate cavitation bubbles in a larger range of water bodies and enhance cavitation;Moreover,the maximum pressure gradient in the choking tube also increases,and the damming section moves downstream,which is favorable for cavitation.(4)When a relatively uniform gas-liquid mixed two-phase flow is generated in the choking cavitation,the number of Ma of the gas-liquid two-phase flow slowly increases from the central position of the choking tube to the position of the damming section along the axis line.When the pressure gradient reaches the pole value,the number of Ma reaches its maximum,its maximum value is 0.97,which is almost 1.