空化射流喷嘴性能分析与试验研究OA北大核心CSTPCD

In order to enhance the impact effect of cavitation jet,the impact performance of cavitation nozzle jet was studied by using the method of combining numerical simulation and experimental research.The cavitation impact effect of conical nozzle,contraction and expansion nozzle,Helmholtz nozzle and organ pipe nozzle was compared,and the impact of impact standoff distance on the impact performance of nozzle was deeply studied.The results show that the cavitation bubbles generated in the nozzle will go through three stages:initial,development and collapse.The cavitation bubbles are initially generated in the nozzle,and finally develop to the limit state in the external flow field,and then collapse near the impact target,thus producing a strong impact force.Compared with conical nozzle,contraction and expansion nozzle and Helmholtz nozzle,organ pipe nozzle has the best cavitation impact effect.Under the same working conditions,the time for the organ pipe nozzle to penetrate the sleeve is the shortest,and the impact time is shortened by 90%compared to the conical nozzle.The size of the impact hole formed is expanded by 80%compared to the conical nozzle;The impact standoff distance has a significant impact on the impact performance of nozzle cavitation.Within a certain range,with the increase of the impact standoff distance,the impact performance of cavitation jet shows a trend of first increasing and then decreasing.Compared to the impact standoff distance of 5 mm,the sleeve piercing time of the organ pipe nozzle is shortened by 41.4%when the impact standoff distance is 10 mm.The results of this study can provide a theoretical basis for the application of cavitation jets.