High velocirt flows of dense gases

1.本文对范德华气体中的激波跃迁进行了分析和数值研究。证明了pv平面上的两个激波绝热线可以在四个点相交。这在完美气体中是不会发生的。在特殊情况下，一次冲击会受到两次连续冲击转变的同等影响。超声速-超声速激波至少在数值上得到了稳定的模拟。为验证该装置的有效性和安全性，搭建了n-pentan激波管，并进行了基础实验。设计并建造了反射激波隧道。3 .在激波通道中实现了正戊烷的自由射流，用光学方法（施连照片）观察了液体激波和激波分裂。从理论分析上证明了负基导数GAMMA的气体状态很难通过n-pentan的激波压缩实现。这是因为正戊烷的比热非常大，不能被激波压缩有效加热。这表明，极高温气体（300-400 K）的激波管是实现负GAMMA气体状态的必要条件。为了今后的实验研究，需要对现有设备进行改进和改进。

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.