Simulation Study On Oscillating Cavitation Nozzle Based On FLUENT

Nowadays, the cavitating water jet technology has a rapid development. It is a new type of water jet technology with many advantages like low working pressure, strong impact pressure, environmental protection and energy saving. But the study of cavitating water jet still need improvement, such as the specific structure parameters and how to improve the power of impact of cavitating water jet. This thesis will study on these problem.In cavitation water jet system, the key component for the jet performance is nozzle. In this thesis, the numerical simulation of flow field of the nozzle interior was carried out and analyzed by FLUENT in Workbench from ANSYS. The influence of the nozzle structure parameters on the internal flow field was studied. Based on the results, a centralized and rotary cavitation jet nozzle was designed.The basis structure of self-oscillating cavitation jet nozzle based on theory study was put forward in the thesis. It includes the diffusion angle, the diffusion length and the cylindrical length of jet nozzle. During the numerical simulation,, a mixture model and RNG k ?? model was utilized based on FLUENT. After meshing, setting up physical model, cavitation model, initial conditions and boundary conditions(entrance pressure of nozzle is 20MPa) on structure with different parameters, The the simulation and analysis was initialized. By stimulation and analysis, a profile along the X axis direction was created. By comparing the pressure contours and velocity contours in x-y plot, the optimized structure parameters of self-oscillating cavitation jet nozzle was obtained.This thesis designs a centralized rotary cavitation jet nozzle and constructs 3D model of the nozzle which is special to increase the gas flow structure and set the entrance pressure of vent-inlet about 10 MPa. This thesis focus on analysing the main structure parameter of centralized rotary cavitation jet nozzle such as air inlet quantity, slope angle and spacing between different structure, which have influence on the performance of the nozzle. According to orthogonal experiment research, we get the centralized rotary cavitation jet nozzle with the optimal parameter combination, which provides a theoretical guidance for the application of this type of nozzle.