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实验研究了真空环境液体排放过程(特别是出口射流)的热动力学特征,分析了3种不同射流形态(连续液体射流、部分闪蒸射流和完全闪蒸射流)间的转换条件,发现基于气泡生长机制的Cleary模型低估了闪蒸所需过热度,较早预测了闪蒸射流的发生;而基于核化机制的Lamanna模型会高估闪蒸所需化学势差,预测的闪蒸发生晚于实验观测结果。闪蒸引起的流量壅塞效应对真空液体排放流量的影响依赖于初始过冷比RP,0=P_0/P_(sat)(T_0),除非初始过冷比远大于1,一般需要考虑闪蒸引起的实际排放流量变化,即明显低于不可压理论的估算结果。
The thermodynamic characteristics of liquid discharge in vacuum environment (especially the exit jet) were experimentally studied. The conditions of transition between three different jet modes (continuous liquid jet, partial flash jet and complete flash jet) were analyzed. The Cleary model of the growth mechanism underestimates the superheat required for flash and earlier predicts the flash jet. The Lamanna model based on the nucleation mechanism overestimates the chemical potential difference required for flash. The predicted flash occurs later than Experimental observation results. Flash-induced flow congestion effects on vacuum liquid discharge flow depend on the initial subcooling ratio RP, 0 = P_0 / P_ (sat) (T_0) unless the initial subcooling ratio is much greater than 1, generally due to flash-related The actual change in discharge flow, which is significantly lower than the theory of incompressible estimates.