Hydrodynamic Analysis Of Ultra-high Pressure Water Jet Of Marine Rotate Derusting Nozzle

The surface treatment process has a great influence on the adhesion performance and life of the substrate coating.At present,the vast majority of domestic ship repair companies mainly adopt manual shot blasting and rust removal.Not only the work efficiency is low,the rust removal effect is poor,but also there are a series of problems such as serious pollution to the air environment.The ultra-high pressure water jet can be used to cut materials and remove various surface attachments,basically without affecting the mechanical properties of the processed materials,and has the characteristics of low energy consumption,low pollution,high efficiency,low cost,and easy operation.So far,the design parameters of the nozzle used in many complete sets of equipment are generally determined by referring to the relevant parameters of similar foreign products and combining on-site experience,so it is difficult to ensure the jet efficiency.At present,while optimizing jet performance and increasing cleaning efficiency,it has become a top priority to select appropriate working parameters to reduce various costs.In this paper,the influence of the characteristic parameters of the single fixed angle of attack and the multi-beam rotating jet in the ultra-high pressure water jet on the jet effect,as well as the simulation analysis of the nozzle layout on the rotating nozzle during the working process.First,according to the working characteristics of the ultra-high pressure water jet rust removal nozzle,considering the compressibility and cavitation effect of water,a three-dimensional model of a single-beam fixed angle of attack and multiple-beam rotating nozzle was established,and the model validity and grid dependence were determined.Through the verification of simulation data and experimental data,it can be seen that the numerical calculation results and the experimental data show good consistency,and the numerical error is within the ideal range.Then,by changing the relevant characteristic parameters,such as the length-to-diameter ratio and convergence angle of the nozzle inside the nozzle in the single-beam fixed-angle of attack model,the target distance and incident angle outside the nozzle,and the rotation speed of the nozzle in the multi-beam rotating nozzle model,the super The hydrodynamic performance of the high-pressure water jet rust removal nozzle structure is simulated and calculated,and the flow field characteristics of the ultra-high pressure water jet under multiple working conditions are obtained.Finally,track the sweep trajectory of the multiple rotating nozzles in the working process,and analyze the sweep situation at different positions in the sweep area,so as to coordinate the nozzle position,nozzle translation speed and other parameters that affect the cleaning effect,and get the basic nozzle layout Ideas and layout d esign of a rotating plane cleaning nozzle.The results of the study preliminarily explained the mechanism of jet impact stripping,clarified the influence of the characteristic parameters of a single fixed angle of attack and multiple rotating jets on the jet effect,and provided a method for analyzing high-speed rotating jets,as well as ultra-high pressure rust removal.And put forward suggestions on the design and assembly of ultra-high pressure derusting nozzles.