Experimental investigation of the shock-induced flow over a wall-mounted cylinder
Experimental investigation of the shock-induced flow over a wall-mounted cylinder
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DOI：
10.1017/jfm.2018.433
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发表时间：
2018-06-26
影响因子：
3.7
通讯作者：
Laurence, S. J.
中科院分区：
文献类型：
--
作者：
Ozawa, H.;Laurence, S. J.
本文研究了激波诱导超声速边界层流动与壁面圆柱相互作用引起的非定常气动力和气动现象。在激波管中进行了三种不同的激波后单位雷诺数和一个单一的马赫数的实验，以研究不同比例的无粘和粘性的时间尺度上的流动发展的影响。两个气缸的高度进行了研究：“大”和“小”突起的基础上计算的边界层厚度。激波管壁的热通量测量使用超快速响应的温度敏感涂料进行，并通过独立的热电偶测量进行验证。高速纹影提供了无粘流动现象的可视化。圆柱体前的非定常激波/边界层干扰导致了较高的瞬态热损失。在壁面上产生撞击，并使进入的层流边界层转变为湍流。一旦进入的边界层自然过渡，增强的热通量区域就会向圆柱体收缩;在此过程中，直接尾流中的传热显著增加。圆柱体上游的总热通量对于大突起来说较高，而下游热通量对于小突起来说一般较高。在大突起的情况下，粘性结垢似乎是最好的崩溃的上游热通量的发展为三个不同的单位。雷诺数，但下游的协议是不太令人满意的。粘性和非粘性缩放似乎都没有充分破坏小突起的发展。
The unsteady aerodynamic and aerothermal phenomena resulting from the interaction between a shock-induced supersonic boundary-layer flow and a wall-mounted cylinder are investigated. Experiments were conducted in a shock tube at three different post-shock unit Reynolds numbers and a single Mach number to investigate the effects of differing ratios of inviscid and viscous temporal scales on the flow development. Two cylinder heights were studied: 'large' and 'small' protuberances based on calculated boundary-layer thicknesses. Heat-flux measurements on the shock-tube wall were performed using an ultra-fast-response temperature sensitive paint and verified by independent thermocouple measurements. High-speed schlieren provided visualizations of the inviscid flow phenomena. The unsteady shock-wave/boundary-layer interaction ahead of the cylinder resulted in high transient heat lo. ding on the wall and caused transition to turbulence of the incoming laminar boundary layer. Once this incoming boundary layer had naturally transitioned, the region of enhanced heat flux collapsed back towards the cylinder; during this process, heat transfer in the immediate wake increased significantly. The overall heat flux upstream of the cylinder was higher for the large protuberance, whereas the downstream heat flux was generally higher for the small protuberance. In the case of the large protuberance, the viscous scaling appeared to best collapse the upstream heat-flux development for the three different unit. Reynolds numbers, though the agreement downstream was less satisfactory. Neither the viscous nor the inviscid scaling appeared to adequately collapse the development for the small protuberance.