Numerical Simulation on Internal Flow Field in Nozzle with Cavitations Water Jet

Physical model is established according to the nozzle structure,and the κ-e turbulence model is used to establish mathematical model,the SIMPLEC arithmetic is used for simulation.The result shows that the jet has the maximum velocity value in the cylindrical section,and the negative-pressure is favourable for the cavitations bubble to exist in the diffuser because of the intensely shearing action between jet and surrounding medium.The diffuser angle of the nozzle has great influence on the internal flow field,and has the optimal value of 30°.The diffuser length of the nozzle also has some influence on the internal flow field,the primary value is 12 mm.The cylindrical section length of the nozzle affects the internal flow field less,and the value is 2~10 mm,the initial value is 4 mm.