超声速气流中爆轰波与边界层相互作用机理研究

The structure of detonation wave in supersonic flows is very different from that in quiescent gas. The boundary layer in supersonic flow not only leads the detonation wave surface incurvature, but also induces the detonation velocity different from CJ velocity of still gas. This item aims to study the interaction of detonation wave and boundary layer in supersonic flows. An upstream detonation wave will form in the supersonic premixed flows, and then the two dimensions structure of detonation, especially the fine combustion structure and dynamic development will be investigated by experimental and numerical methods. To analyze the interaction of detonation wave and boundary layer in supersonic flows, the boundary layer development in cold and hot states, the detonation propagation mechanism and the interaction between them will be researched. To study the effects of laminar boundary layer and turbulent boundary layer on detonation propagation, effective boundary control methods such as boundary layer transition are adopted. To study the effects of boundary layer thickness on detonation propagation, boundary layer suction and thickening are also adopted. One dimension model of detonation in supersonic flows influenced by boundary layer will be found. New methods of controlling and utilizing detonation wave in supersonic flows will be discussed.

超声速运动气流中的爆轰波结构和传播特性与静止气体中存在很大的差异，超声速气流中的边界层不仅使近壁面爆轰波阵面发生弯曲，还使爆轰波的传播速度与静止气体中的CJ 理论速度相比发生较大的偏差。本项目以超声速可燃混合气流中爆轰波与边界层的相互作用为研究对象，在连续超声速可燃混合气中，产生逆流传播的爆轰波，采用实验观测和数值模拟观察其二维动态特征，尤其是二维精细燃烧流场结构及其动态变化，分析超声速气流中爆轰波与边界层相互作用的过程，重点研究冷、热态条件下边界层发展规律，超声速条件下爆轰波传播机理及传播规律以及爆轰波与边界层相互影响规律。通过有效的边界层控制方法，比如通过转捩控制来研究层流边界层和湍流边界层对爆震波传播的影响，通过边界层吹除、抽吸以及气动增厚等措施来研究边界层厚度变化对爆轰波传播的影响；建立考虑边界层影响的超声速气流爆轰波准一维模型，寻找控制和利用超声速气流中爆轰波的新方法。

以高超声速飞行的爆轰发动机为研究背景，采用理论分析、实验研究和数值模拟相结合的方法，对超声速气流中爆轰波与边界层的相互作用开展了系统研究。首先通过实验对超声速气流中边界层效应下的斜爆轰波的起爆和前传进行了研究。发现边界层分离区可以改变斜爆轰波的形态（突跃或平滑）。随后研究了驻定斜爆轰波与边界层的相互作用，发现小尺度分离下的斜爆轰波驻定形态与大尺度分离下的斜爆轰波驻定形态有很大差异。最后通过数值模拟研究了斜坡诱导的斜爆轰波与边界层的相互作用，其结果与实验结果很好地相互佐证。