诱导轮内部液氢空化流动特性

为了研究以液氢作为流动介质的诱导轮的空化特性,采用数值模拟方法分别计算了诱导轮内部液氢和水的空化流动.计算中采用一种基于Kubota模型自开发的且考虑热力学效应影响的空化模型,湍流模型采用SST k-ω双方程模型,计算模型和方法通过试验进行了验证.通过对比计算,获得了2种介质在不同空化条件下诱导轮内部的空化流场,分析了2种介质下诱导轮的能量性能和空化性能.结果表明:修正的Kubota空化模型能够很好地模拟考虑空化热力学效应的诱导轮内部液氢的空化特性;相比水体而言,液氢为流动介质时诱导轮扬程有所提高,临界空化数变小,空化区域减小,这是由于介质特性特别是热力学效应的影响;以液氢为介质时,诱导轮的空化性能相对于水介质将有明显的改善,初生空化数将减小.

Characteristics of cavitating flow of liquid hydrogen in inducer

A revised Kubota cavitation model to consider the thermal effect and the SST k-ω two-equation turbulence model were applied into the simulation of cavitating flows of liquid hydrogen and water in an inducer to study its cavitation characteristics. Not only the cavitating flows in the inducer under different cavitation conditions with those fluids were numerically predicted, but also the power and cavitation performances were analyzed. It was found that the revised Kubota cavitation model can simulate the liquid hydrogen cavitating flows very well, and a good agreement was achieved between the numerical results and experiment data. Compared with water, the inducer head with liquid hydrogen is higher, and the critical cavitation number and cavity size are smaller. This is due to the diffe-rence in physical properties of two fluids, especially the influence of their thermal effect. Cavitation performance of inducer is obviously improved and its incipient cavitation number is decreased when li-quid hydrogen is used as the working fluid compared with water. 