The influence of shock speed variation on radiation and thermochemistry experiments in shock tubes
The influence of shock speed variation on radiation and thermochemistry experiments in shock tubes
复制标题
激波速度变化对激波管辐射和热化学实验的影响
DOI：
10.1017/jfm.2022.727
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发表时间：
2022
影响因子：
3.7
通讯作者：
M. McGilvray
中科院分区：
文献类型：
--
作者：
P. Collen;M. Satchell;L. di Mare;M. McGilvray
摘要激波管是进入大气层飞行器气动热力学模型实验数据的重要来源。值得注意的是，许多化学动力学和辐射模型直接对这些设施的光学测量进行验证。通常，实验测量位置处的入射冲击速度被认为是测试段塞的代表;然而，冲击速度在该位置的上游可能会发生很大变化。这些变化长期以来一直被认为是与计算预测不一致的原因，尽管最终的联系已经被证明是难以捉摸的。这项工作描述了一系列的实验，旨在隔离和确认的冲击减速效果的重要性。这是通过产生不同的冲击轨迹，并比较原子氧发射和电子密度的冲击后的趋势。这些趋势被证明是直接联系到上游冲击速度的变化，使用最近开发的数值工具（LASTA）。比较的密切一致性证实了激波管实验中激波速度变化的重要性;这些发现对过去和现在的所有此类研究都具有直接和潜在的重要意义。
Abstract Shock tubes are a crucial source of experimental data for the aerothermodynamic modelling of atmospheric entry vehicles. Notably, many chemical-kinetic and radiative models are validated directly against optical measurements from these facilities. Typically, the incident shock speed at the location of the experimental measurement is taken to be representative of the test slug; however, the shock velocity can vary substantially upstream of this location. These variations have been long posited as a source of disagreement with computational predictions, although a definitive link has proved elusive. This work describes a series of experiments which aim to isolate and confirm the importance of the shock deceleration effect. This is achieved by generating different shock trajectories and comparing the post-shock trends in atomic oxygen emission and electron density. These trends are shown to be directly linked to the upstream shock speed variations using a recently developed numerical tool (LASTA). The close agreement of the comparisons confirms the importance of shock speed variation for shock tube experiments; these findings have direct and potentially critical relevance for all such studies, both past and present.