中文摘要：

喷嘴结构及射流运动参数对液体空化流动状态有重要影响。基于空化泡溃灭的雾化机理和自激振荡脉冲喷嘴出口流道空化过程,分析空化效应对自激振荡脉冲射流雾化效果的影响。依据自激振荡脉冲雾化喷嘴结构,分析射流来流速度和脉动压力对喷嘴出口流道空化效应的影响,提出利用来流雷诺数和脉动特征值表征喷嘴出口流道空化程度,并根据自激振荡脉冲喷嘴有限元分析得到喷嘴出口流道较好空化状态的来流雷诺数和喷嘴腔室长径比。研究结果表明：当来流雷诺数在2.14×10~5~3.05×10~5内逐渐增大时,自激振荡脉冲雾化喷嘴出口流道液相体积分数先减小后增大,相应的空化程度先增大后减小。雷诺数在2.44×10~5~2.75×10~5内可以使喷嘴出口流道形成较好空化效应,尤其在2.44×10~5附近时喷嘴出口流道出现最好的空化状态;脉动特征值与喷嘴出口流道处脉动压力幅值差成正比,随着自激振荡脉冲雾化喷嘴腔室长径比增大,脉动压力幅值差值先减小后增大。当喷嘴腔室长径比为0.60~0.70时,喷嘴出口流道空化状态较好。计算结果为自激振荡脉冲射流雾化喷嘴设计提供了理论依据。

英文摘要：

The nozzle structure and jet motion parameters play the important role in the liquid＇s cavitation flow state. Based on the atomization theory caused by cavitation bubble breaking and the cavitation forming process of self-excited oscillation pulsed nozzle＇s outlet channel, the jet cavitation effect on the self-excited oscillation pulsed jet atomization effect is analyzed. On the basis of self-excited oscillation pulsed atomization nozzle structure, the influence of the jet velocity and fluctuating intensity for the cavitation effect of nozzle＇s outlet channel are analyzed, meanwhile, the flow Reynolds number and fluctuating pressure are raised for demonstrating the outlet channel cavitation degree, and the Reynolds number and the nozzle chamber aspect ratio are acquired which could guarantee better cavitation state of nozzle＇s outlet channel based on the self-excited oscillation pulsed nozzle finite element analysis. The results show that：When the coming flow Reynolds number increases gradually within 2.14×10~5-3.05×10~5, the liquid volume fraction of the self-excited oscillation pulsed atomization nozzle＇s outlet channel decreases firstly, and then increases, the corresponding cavitation degree enhance firstly and then weaken. The better cavitation effect in self-excited oscillation pulsed atomization nozzle＇s outlet channel is formed when Reynolds number is in 2.44×10~5-2.75×10~5, the best cavitation state in the outlet channel will appears when the Reynolds number is about 2.44×10~5. Fluctuating characteristic value is proportional to the nozzle outlet channel fluctuating pressure amplitude difference, when the self-excited oscillation pulsed atomization nozzle chamber aspect ratio increases, the fluctuating pressure amplitude difference increase firstly, and then decrease. When the nozzle chamber aspect ratio is 0.60-0.70, the nozzle＇s outlet channel cavitation state is better. The results provide theoretical basis for the design of self-excited oscillation pulsed atomization nozzle.