流向弯曲壁超声速湍流边界层研究进展

Overview on progress of supersonic turbulent boundary layer on curved surfaces

流向弯曲壁面上的超声速湍流边界层特性是流体力学的重要科学问题,掌握其规律对提升高超声速飞行器设计水平有重要意义。国内外在该问题上的研究已经持续了50余年,近年来随着实验测量和数值模拟能力的提高,在流向曲率的影响机理上取得了突破性进展。本文系统梳理了流向凸曲壁及凹曲壁的超声速湍流边界层的演化机制,介绍了流向曲率、压力梯度和体积膨胀/压缩等关键因素的影响规律,总结了流向凸曲壁边界层湍流衰减的特性与成因,以及凹曲壁边界层中Gortler不稳定和逆压梯度增强湍流的特性与成因。最后归纳其发展趋势,为下一步开展弯曲壁超声速湍流边界层研究提出了建议。

The characteristics of the supersonic turbulent boundary layer subjected to the streamwise curved wall surface is an important scientific issue in fluid mechanics.To know clearly its laws is of great significance for improving the design level of hypersonic vehicles.Research on this issue in the international community has continued for more than 50 years.In recent years,with the improvement of experimental measurement and numerical simulation capabilities,breakthrough progress has been made in the influence mechanism of streamwise curvature rate.This paper systematically summarizes the evolution mechanism of supersonic turbulent boundary layer subjected to convex curved wall and concave curved wall,introduces the influence law of key impact factors such as flow direction curvature,pressure gradient and volume expansion/compression.The characteristics and causes of turbulence attenuation of convex supersonic wall boundary layer,as well as the characteristics and causes of Gortler instability and backpressure gradient enhanced turbulence fluctuation in the concave supersonic wall boundary layer,is summarized.Finally,the developing trend is summarized,and suggestions are made for the next step of research on the curved wall supersonic turbulent boundary layer.