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ANALYSIS OF AXISYMMETRICAL SHOCK FOCUSING PHENOMENONS BY FLOW VIZUALIZATION,MEASURMENTS OF PRESSURE AND DENSITY AND NUMERICAL CALCULATIONS

流场可视化、压力、密度测量及数值计算分析轴对称激波聚焦现象

基本信息

批准号：
05650184
负责人：
KISHIGE Haruaki
金额：
$ 1.15万
依托单位：
NARA NATIONAL COLLEGE OF TECHNOLOGY
依托单位国家：
日本
项目类别：
Grant-in-Aid for General Scientific Research (C)
财政年份：
1993
资助国家：
日本
起止时间：
1993 至 1994
项目状态：
已结题

项目摘要

Computational and experimental studies of focusing of shock wave reflected from an axisymmetrical parabolic wall were conducted. The shadowgraph fo a focusing shock wave were optically visualized in the shock tube experiments and compared with the computer shadowgraphs which was developed based on the principle of optical shadowgraph. The comparison gives a fairly good agreement. The gasdynamic focus determined by optical shadowgraphs almost agree with the calculated ones.It is seen from the comparison of the computations and experiments, that the measurement of pressure history at the bottom of the reflector supports the numerical simulation. Furthermore, numerical studies of focusing process with vibrationally excitated case have been performed. The results show that the vibrational relaxation plays an important role for the shok focusing phenomena and the gasdynamic focus defined as the maximum pressure position dose not appear in the case of incident shock Mach numbers lager than 5.

对轴对称抛物面壁面反射冲击波的聚焦问题进行了计算和实验研究。在激波管实验中对聚焦冲击波的阴影进行了光学可视化，并与基于光学阴影原理开发的计算机阴影进行了比较。比较得出了相当一致的结论。由光学阴影图确定的气动力焦点与计算值基本一致。从计算与实验的对比中可以看出，反射器底部压力历史的测量结果支持数值模拟。此外，还对振动激励情况下的聚焦过程进行了数值研究。结果表明，振动弛豫对激波聚焦现象起重要作用，在入射激波马赫数大于5的情况下，不出现以最大压力位置定义的气动力聚焦。