The paper presents a theoretical study for a supersonic boundary layer over a flat plate in a stream of air at Mach number M = 2 under the conditions of surface sublimation. The sublimation-prone material is naphthalene (C₁₀H₈). Calculations demonstrated that at a higher surface temperature the mass flowrate of naphthalene evaporation is increasing. This reduces the wall temperature in comparison with a similar flow without sublimation. The high molecular mass of naphthalene (vs. air) and reduction of wall temperature due to the wall material evaporation creates a higher density of the binary gas mixture (air and naphthalene vapor) near the wall. This modification of the boundary layer profiles induces a significant reduction of instability growth rate. This fact was confirmed by calculations based on the linear stability theory. It was found that boundary layer stabilization occurs for growing sublimation surface temperature; it becomes a maximum near the triple point temperature of the coating material. The e^N method gives the estimates of the Reynolds number for laminar-turbulent transition. This shows a theoretical possibility of extension of the laminar boundary layer above a model with sublimation coating.

中文翻译：

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升华表面超音速边界层的稳定性

本文对表面升华条件下马赫数M = 2的空气流中平板上的超音速边界层进行了理论研究。易于升华的材料是萘（C ₁₀ H ₈）。计算表明，在较高的表面温度下，萘蒸发的质量流量正在增加。与没有升华的类似流动相比，这降低了壁温。萘的高分子量（相对于空气）以及由于壁材料蒸发而导致的壁温降低在壁附近产生了更高密度的二元气体混合物（空气和萘蒸气）。边界层轮廓的这种改变引起不稳定性增长率的显着降低。通过基于线性稳定性理论的计算证实了这一事实。发现随着升华表面温度的升高，边界层稳定。它在涂料的三点温度附近变为最大值。的ë ^Ñ方法给出了层流湍流转变的雷诺数估计值。这显示了在具有升华涂层的模型上方扩展层状边界层的理论可能性。