高超声速流动的转捩和湍流研究

Hypersonic boundary layer flow transition prediction in the near space will be studied in the project. How the dissociation or ionization resulted from the high temperature close to the surface of flying vehicle affects transition is worth of studying. Especially we need to improve eN method, which is considered as an efficient one to predict transition position. Some typical hypersonic boundary layer flows such as flat plane and small blunt cone ones would be dealt with. In order to develop a reliable transition criterion, first, we should provide the initial perturbations for eN method by the receptive theory. Then, basing on the results predicted by NPSE, and being compared to that by eN methods, we will put forward a criterion. Finally, we would study how the real gas effects affect the position of transition. The results can be served as transition prediction for hypersonic boundary layer flow and can be reference basis for practical engineering applications.

针对近空间高超声速飞行器有关的典型流动，研究高温引起的离解和电离对转捩的影响，在理论和算法方面进一步完善eN和PSE方法。典型流动包括平板和小球头锥的高超声速边界层流动。本项目研究主要包括：通过研究感受性问题，给出eN方法中所需初始扰动的理论依据；然后基于NPSE对转捩位置预测的结果，与采用eN方法的结果进行比较，以给出可靠的转捩判据；研究高温真实气体效应对转捩的影响规律。所得结果将可用于高超声速飞行器壁面的边界层转捩预测，为实际工程应用提供参考依据。

针对近空间高超声速飞行器有关的典型流动，考虑高温真实气体效应，采用eN方法和PSE方法，对典型的高超声速边界层流动楔体和钝锥边界层进行转捩预测研究。开展的主要工作和获得的主要成果：1.对不同来流马赫数和不同壁面条件下的高超声速楔体和零攻角钝锥边界层进行转捩预测研究，得出了高温真实气体效应对转捩位置的影响情况；并对三维高超声速边界层中eN方法应用开展了探索研究。2.提出了一种简便方法进行变比热高超声速平板边界层流动直接数值模拟计算。3.在PSE方法的应用方面开展了研究工作，提出了可压缩边界层的更自洽的PSE方法。4.开展了高超音速流动气动加热对流换热系数确定的研究。所得研究结果为实际工程应用提供了参考依据。