二级节流阀口空化特性表征研究

探讨了二级节流阀口空化概率的表征，并在经典空化数σ基础上提出了适用于二级节流阀口空化剧烈程度表征的空化指数计算式。在节流阀口空化表征基础上研究了U形和V形节流阀口的空化特性曲线,得出如下结论：U形和V形节流阀口的空化气蚀剧烈区始终集中在较小过流截面A2上，并且当阀口体积流量方向反转时节流空化特性表现出明显差异；当流体流入过流截面A1时A2截面上的空化指数要大于流体流出过流截面A1时A2截面上的空化指数,从宏观上则反映为流入截面A1时的体积流量要小于流出A1时的体积流量。

Study on Two-stage Throttle Port Cavitation Characterization

The cavitation characterization of two stage throttle port was studied,and using classical cavitation definition σ,new-form cavitation characterization index  was obtained,which was applicable,to two stage throttle port.In the calculation formulae of new-form  cavitation  characterization index,all design parameters needed by two-stage throttle port  were included.Applying the calculation formule,cavitation characterization curves of  U  and  V  throttle ports were plotted,and it is observed from the plots that whether U or V throttle port, cavitation concentration region is always around section A2,and that the cavitation characterization index of section A2  when liquid flows into section A1  is always larger than that of  A2 when liquid flows out from section A1;the macroscopic phenomena is that flow rates of different flow directions are different, and also flow rate out of section A1  is  larger   than that of  flow rate into section A1.