The Simulation Research Of The Hige-pressure Abrasive Water Jet Cutting

This paper is based on FLUNENT6.3package of the CFD simulation software. Theresearch is a simulation of single-phase flow and two-phase flow about the Jet of premixedabrasive, which is in the non-submerged state. Through the simulation analysis of the impactof changes the parameters of the nozzle structure and jet cutting process parameters on the jetflow field. At the non-flooded condition, exploring the law of the structural parameters,abrasive parameters and operating parameters of nozzle influence the flow field of abrasivejet cutting nozzle. Finally, using orthogonal experiment optimizes the process parameters ofcone straighter nozzle, and the results of optimize simulation is consistent with theoreticalanalysis.This paper has a simulation analysis of the jet flow field, from inlet diameter, thediameter of nozzle, contraction angle, the contraction length of cone straight nozzle and themixing tube length of nozzle. The main results are following: When the purpose of jetmachining is cutting, we found that the cutting ability is more powerful when the nozzlecontraction angle between13°~16°. The change of mixing tube length is almost nocontribution to improve the speed of the jet. Increase the mixing tube length of the jet alongthe resistance also increased the difficulty of the nozzle manufacturing; the nozzle diameterand the size of the inlet diameter have a great impact on the jet speed.Jet cutting process parameters mainly include target distance, angle of incidence, andabrasive parameters. The target distance study shows the cutting ability is stronger than anyother target distance, the result between5d-10d. And the results of incidence anglesimulation show that the cutting ability is the strongest when the incidence angle is90°,because all the kinetic energy of cutting convert ton the stagnation pressure. Throughsimulation studies on the concentration of abrasives and abrasive particle size, When theabrasive volume accounted for the entire fluid volume70%, the cutting capacity is strongest.Abrasive size has no effect on jet velocity, but abrasive too big to plug the nozzle and toosmall one will reduce the kinetic energy.Last, using orthogonal experiment to design the simulation experiments, and analyzefour independent process parameters of cone straight nozzle. Besides, this paper designed aexperimental form which content3levels and4factors, and analyze that each parameterinfluence to the fluid velocity of the nozzle exit. what’s more, we get each parameterrelationship and which influence the velocity of the nozzle exit, and get the trend which eachparameter impacts the velocity. Finally, we get the simulation results by choosing the best structure parameter combination of the nozzle which is consistent with theoretical analysis.In short, this thesis has an important significance on nozzle design and jet cutting processparameter selection.