通气空泡发展过程及其水动力影响

在水洞中对通气空泡发展过程及其对水动力影响开展了系列实验研究,发现通气空泡发展经过局部空泡和超空泡两个阶段,回注射流在局部空泡和超空泡阶段的表现形式不同,对空泡形态的影响也不同,根据空泡形态的显著变化可以得到局部空泡过渡到超空泡的转变判据.空泡数和模型阻力在局部空泡阶段随通气率的增加而减小;在过渡阶段随通气率的微小增加而迅速减小;在超空泡阶段随通气率的增加基本保持不变.通气空泡形态不稳定主要表现为空泡振荡和界面波动,此外空泡形态不稳定还会导致模型动力不稳定.文章对于超空泡控制技术的研究具有重要参考价值.

Development of ventilated cavitation and its effect on hydrodynamics

Development of the ventilated cavitation and its effect on hydrodynamics have been studied through a series of water tunnel experiments. The investigation shows that the ventilated cavitation goes through the phases of partial cavitation and supercavitation, the reentrant jet behaves differently in these two phases, and the transition criterion between them can be achieved from the notable change of cavitation. Cavitation number and model drag decrease with the increasing ventilation rate in partial cavitation phase, they decrease abruptly in transition phase if the ventilation rate increases just a little, and they keep almost unchangeable in supercavitation phase with the increase of the ventilation rate. The instabilities of ventilated cavitation behave oscillatory and fluctuant, they will result in the instability of model dynamics. These experimental results are valuable to the control of supercavition.