ass日本风韵熟妇pics男人扒开女人屁屁桶到爽|扒开胸露出奶头亲吻视频|邻居少妇的诱惑|人人妻在线播放|日日摸夜夜摸狠狠摸婷婷|制服 丝袜 人妻|激情熟妇中文字幕|看黄色欧美特一级|日本av人妻系列|高潮对白av,丰满岳妇乱熟妇之荡,日本丰满熟妇乱又伦,日韩欧美一区二区三区在线

For researching phenomena of the cavitation and the air ingestion in the nozzle under different ambient pressures, a visualization experiment with a transparent injector nozzle was carried out, which used the stroboscope, long-distance microscope, CCD camera, high-pressure spray chamber etc. The VOF method and the overset grid technology were used to simulate transient state flow in the spray orifice and the sac. The simulation results showed that the strong cavitation phenomenon would happen in the orifice and the sac of nozzle after the end of injection. The void volume of the cavitation bubble collapsing was filled with ingested air. And the cavitation volume was roughly equal to the ingested air volume based on the calculated data which can prove the conclusion. This showed that the cavitation collapse was the main cause of air ingestion. The cavitation collapse in the sac was a necessary condition for the ingestion air further flowing into the sac. And the smaller the cavitation area in the sac was, the less hot combustion gas was ingested into the sac. The cavitation number was proposed which represented the degree of cavitation in the nozzle after the end of injection. Further studies found that an increase in ambient pressure can cause the cavitation number to increase which led to the cavitation volume and the ingested air volume tend to decrease. And the cavitation number explained the influence of ambient pressure on air ingestion, and this was consistent with the experiment and simulation results.