Hypersonic shock impingement on a heated flat plate at Mach 7 flight enthalpy
Hypersonic shock impingement on a heated flat plate at Mach 7 flight enthalpy
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7 马赫飞行焓对加热平板的高超音速冲击冲击
DOI：
10.1017/jfm.2020.877
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发表时间：
2020
影响因子：
3.7
通讯作者：
A. Veeraragavan
中科院分区：
文献类型：
--
作者：
E. W. K. Chang;W. Chan;T. Mcintyre;A. Veeraragavan
摘要壁面温度升高和冲击波干扰是高超声速飞行的普遍特征。目前，缺乏关于在飞行代表性环境中检查这两个特征的实验研究的文献。这项工作的细节热壁，高超音速，冲击激波/边界层干扰实验中进行的T4跟踪管。该模型的配置是一个二维加热平板和冲击发生器。在实验运行过程中，石墨平板的表面被连续加热到平均温度从T_w=298 K $到T_w约675 K $。斜激波由相对于自由流倾斜10 ^{\circ }$或12 ^{\circ }$的平板产生，冲击加热平板以引起边界层分离。主流条件产生了马赫数为7的飞行等效供油焓，单位雷诺数为4.93 × 10^6 m ^{-1}$。考虑了更多的低单位雷诺数和低流量的流动条件，以检查流动分离特性。纹影法和红外热成像分别捕捉流场和壁面温度分布。结果表明，随着T_w$的增大和单位雷诺数的减小，流动分离的范围增大。此外，本数据的比例分离与现有的分离关联式有很大的差异，这些关联式是由超音速冲击激波和高超音速压缩斜坡发展而来的，这主要是由于激波强度较高。相反，目前的数据遵循的标度律，其中包括跨冲击波的压力比与壁温比的轻微依赖。
Abstract Elevated wall temperatures and impinging shock interactions are prevalent features in hypersonic flight. Currently, there is a lack of literature regarding experimental studies examining both features in a flight-representative environment. This work details hot-wall, hypersonic, impinging shock/boundary-layer interaction experiments performed in the T4 Stalker Tube. The model configuration was a two-dimensional heated flat plate and a shock generator. The surface of the graphite flat plate was resistively heated to a mean temperature from $T_w=298\ \textrm {K}$ to $T_w\approx 675\ \textrm {K}$ during an experimental run. An oblique shock, generated by a plate that was inclined at $10^{\circ }$ or $12^{\circ }$ to the free stream, was impinged on the heated flat plate to induce boundary layer separation. The primary flow condition produced Mach 7 flight-equivalent nozzle-supply enthalpy with a unit Reynolds number of $4.93\times 10^6\ \textrm {m}^{-1}$. More flow conditions with lower unit Reynolds numbers and flow enthalpies were considered to examine flow separation characteristics. Schlieren and infrared thermography captured the flow field and the wall temperature distribution, respectively. The results showed that the size of the flow separation grew with a higher $T_w$ and a lower unit Reynolds number. Moreover, the scaled separation of the present data showed a high discrepancy with existing separation correlations developed from a supersonic impinging shock and a hypersonic compression ramp, mainly due to the higher shock strength. Instead, the present data followed a scaling law that includes the pressure ratio across the impinging shock with a slight dependence on the wall temperature ratio.