Experimental Investigation of Thermal Shock Wave Induced by Gas Dynamic Shock Wave Impingement
Experimental Investigation of Thermal Shock Wave Induced by Gas Dynamic Shock Wave Impingement
复制标题
气体动力冲击波冲击引起的热冲击波实验研究
DOI：
10.1007/978-1-4615-4215-5_1
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发表时间：
2000
期刊：
影响因子：
--
通讯作者：
M. Murakami
中科院分区：
文献类型：
--
作者：
H. Yang;H. Nagai;N. Takano;M. Murakami
用超导温度传感器测量了He II中的温度变化，研究了He II中的热激波。它是在新开发的超流激波管装置中，通过气体动力激波撞击He II自由面而产生的。发现热冲击的轮廓是单一的三角形波形，具有有限的冲击强度。实验结果表明，热激波不是在撞击瞬间产生的，也不是从原始自由面传播的，而是在比原始自由面稍低且略晚于撞击时产生的。这意味着在热边界层建立后，在其下端产生热激波。在厚度为几mm的热边界层中，通过压缩He I，热力学状态从原来的自由表面的超临界转变为压缩的He II。在接近波长温度的实验中有时发现，在冲击压缩的He II中没有探测到热激波。可以理解，冲击压缩使He II转变为不激发热激波的He I。
The thermal shock wave in He II is investigated by measuring the temperature variation with a superconductive temperature sensor. It is generated by the impingement of a gas dynamic shock wave onto a He II free surface in the newly developed superfluid shock tube facility. The profile of thermal shock is found to be of a single triangular waveform with a limited shock strength. It is suggested from the experimental result that a thermal shock wave is generated not at the moment of the impingement nor propagates from the original free surface, but it is generated at slightly lower than the original free surface and a little later than the impingement. This means that a thermal shock wave is generated at the lower end of a thermal boundary layer after it is established. In the thermal boundary layer with a thickness of several mm, the thermodynamic state changes from supercritical at the original free surface to compressed He II via compressed He I. It is sometimes found in the experiments near lambda temperatures, that no thermal shock wave is detected in shock compressed He II. It can be understood that shock compression makes He II convert to He I where no thermal shock wave is excited.