High velocirt flows of dense gases

1.本文用解析和数值方法研究了货车德瓦耳斯气体中的激波转捩。证明了pV平面上的两条冲击绝热线可以相交于四点。这在理想气体中永远不会发生。在特殊情况下，一个单一的冲击相当于两个连续的冲击过渡的影响。2.建立了正戊烷激波管，并进行了基础实验，验证了实验装置的有效性和安全性。3.设计并建立了反射激波风洞。在激波风洞中实现了正戊烷的自由射流，并用光学方法（Shlieren照片）观察到了液化激波和激波分裂。4.从理论分析上证明了正戊烷的激波压缩很难实现负基本导数的气体状态。这是因为正戊烷具有非常大的比热，因此不能通过冲击压缩有效地加热。这表明，要实现负伽马气体状态，必须采用高温气体激波管（300-400 K）。为进一步的实验研究，需要对现有的实验设备进行改进和完善。

1.The shock transition in the van der Waals gas has been studied analytically and numerically. It was proved that two shock adiabatics in the pV-plane can intersect at four points. This never occurs in the perfect gas. In special cases, a single shock was equivalently effected by two successive shock transitions. The supersonic-supersonic shock waves were stably simulated at least numerically.2.A shock tube for n-pentan was constructed and the basic experiments were performed to check the validity and the security of the equipment.3.A relected shock tunnel was designsd and constructed. Freejets of n-pentan were realized in the shock tunnel and the liquifaction shock and the shock splitting were observed by optical method (Shlieren photographs) .4.From the theoretical analysis, it was proved that the gas stste with a negative fundamental derivative GAMMA is very difficult to be realized by the shock compression for n-pentan. This is because n-pentan has very large specific heat and then cannot effectively be heated by the shock compression. This suggests that the shock tube for very high temperature gas (300-400 K) is necessary to realize the gas state with negative GAMMA. Modification and improvement of the present equipment are needed for the future experimental study.