Numerical Simulation And Optimization Design Of High-Pressure Nozzle Of Marine Aquaculture Net Washing Machine

Aiming at the problems that my country’s marine aquaculture cages are mainly concentrated in the harbor and near the coast,the water flow exchange is poor,and the algae adhesion is more serious and easy to block the mesh of the cage.The core component nozzle is numerically simulated.At the same time,the cavitation jet technology is a commonly used technology in cleaning equipment and is widely used in various cleaning environments.As the core component of the cavitation jet,the nozzle can not only convert the water flow under an atmospheric pressure into a high-pressure water flow,but also ensure the good fluidity and cavitation effect of the cavitation jet.Firstly,understand the offshore working environment of the marine aquaculture net washing machine under aquaculture conditions,analyze and learn the theoretical knowledge of this topic:cavitation and cavitation jet technology,and take two cavitation jet nozzles of angle and shrink tube type as the main research objects.The relative dimensions of the two nozzles are designed to pave the way and prepare for the next simulation study and orthogonal experiment.Secondly,analyze the characteristics and applicable conditions of various numerical calculation models of CFD,namely turbulent flow model,mixing model,cavitation model,etc.,combined with the working conditions of cavitation nozzle s,and finally determine the numerical model of the nozzle in the submerged state:multiphase flow The model adopts the Mixture model,the turbulence model adopts the RNG k-ε turbulence model,and the cavitation model adopts the Zwart-Gerber-Belamri model.Thirdly,using the flow field analysis software,ANSYS FLUENT to analyze the internal flow field of the angle nozzle and the constricted tube nozzle,through the preliminary mesh division and the internal pressure field,velocity field,and gas content of the two cavitation nozzles to compare and analyze,Then,the cavitation effect of the angle nozzle is better,which is more in line with the working state of the submerged working condition of this subject.In order to obtain the optimal structure design of the angular nozzle,the singlevariable method is used to analyze and compare the flow field of different structures that have a great influence on the cavitation effect under the submerged state of the nozzle,and the relatively optimal parameters among different parameters of the same structure are analyzed,and then the nozzle structure is obtained.The optimal value of the parameter.The calculation results show that when the diffusion angle θ is 60°,the length of the cylindrical section is 6 mm,the diameter of the cylindrical section is 1 mm,and the length of the diffusion section is 8 mm,the jet cavitation effect of the nozzle is the best.The analysis found that with the continuous increase of the nozzle inlet pressure,the jet cavitation effect will gradually increase.Finally,The orthogonal test of the cavitation jet nozzle was carried out,and the final result was consistent with the value of the optimized structure obtained by the flow field analysis based on ANSYS FLUENT,which verified the authenticity and rationality of the research on this topic.