Optimization Of Structural Parameters Of Cavitation Jet Nozzle

Cavitation jet technology combines water jet technology with the phenomenon of cavitation.It enhances the strength of the water jet with the use of powerful impact of bubbles collapse.It is widely used in situation of industrial cleaning,drilling and material damage because of erosion energy and work efficiency.It is a promising hot area of academic research at home and abroad.In this paper,based on the cavitation theory,the cavitation process of submerged water jet is simulated by Fluent.And the difference between different nozzle models is compared.Finally,cavitation experiments is carried out,and a set of optimal nozzle parameters is optimized to verify the efficiency of cavitation jet and the feasibility of the experiment.Specific work includes the following:(1)The numerical model of Fluent fluid is used to calculate the internal flow field of cavitating jet in nozzle model,namely the multiphase model is the Mixture model,the cavitation model is the Singhal model,the turbulence model is RNG and the transient time step is 1e-4s.Through the numerical simulation of Fluent,the data of liquid cloud,pressure cloud and velocity distribution of different nozzle models are obtained,which can provide a strong support for the optimization design of nozzle structure parameters.(2)The nozzle with different size parameters is designed and manufactured,the entrance pressure is 35MPa,and the experimental material is 1600 aluminum alloy.The best experimental parameters are found by analyzing the striking effect under different parameters and changing the nozzle matching parameters.The main experimental results are as follows:1)The center erosion spot is caused by the high velocity water impact,and the outer crater of the erosion ring is cavitation.2)In the reasonable range of erosion target distance S,the erosion effect is better,and the S range is 70mm-120mm.3)Considering the erosion outside diameter,erosion area and erosion ring pit density,when the nozzle diameter were 1.2mm,1.4mm and 1.5mm,the best parameters of the nozzle combination optimization(nozzle parameters as d-D-L-dc-Ds-Ls)are 1.2-9.6-9.6-2-6-6,1.4-12-12-3-12-12 and 1.5-12-12-3-6-6.4)Through the analysis of a large number of experimental results,it is concluded that the nozzle parameters affecting nozzle B erosion effect are d,D and L,followed by Dc,Ds and Ls.5)By comparing the optimum nozzle parameter combinations with different nozzle diameters,it is concluded that the d:D:L approximation is equal to 1:8:8.