凹腔结构对圆形超燃冲压发动机燃烧室阻力特性影响

Cavity configuration effect on drag characteristic of round scramjet combustor

凹腔作为促进燃烧室中燃料与来流混合和稳定燃烧的有效手段之一,其研究已引起人们的广泛关注。采用数值模拟方法,探索了圆形超燃冲压发动机燃烧室阻力特性随凹腔结构参数的变化趋势,同时初步考察了飞行攻角对凹腔阻力特性的影响。研究发现,凹腔摩阻相比压阻很小,凹腔对燃烧室的阻力特性主要体现在其压阻上;随着后掠角的增大,热试和冷流状态下的凹腔阻力均呈现逐渐减小的趋势;随着长深比的增大,热试状态下的凹腔阻力先增加后减小,而冷流状态下的凹腔阻力则单调递减;在小攻角（-3°~3°）热试状态下,燃烧室凹腔阻力明显强于冷流状态下凹腔阻力。这对圆形超燃冲压发动机燃烧室的设计工作具有一定的指导和借鉴意义。

As one of the most effective methods to promote the fuel and the incoming air in the combustor to mix and combust steadily,the research of cavity has drawn an ever increasing attention.The effect of cavity configuration parameters on drag characteristic of round scramjet combustor was discussed by using numerical simulation method.Meanwhile,the effect of the angle of attack on the drag characteristic of the cavity was investigated preliminarily.The results show that the frictional drag of cavity is much less than its pressure drag,the drag of cavity on combustor mainly embodies its pressure drag characteristic;with the increasing of sweep-back angle,the drag of cavity decreases gradually under the conditions of engine ignition and cold flow.With the increasing of the ratio of the length to the depth,the drag of cavity increases at first,then decreases under the condition of engine ignition,but under the condition of cold flow,the drag decreases gradually.When the angle of attack is between-3°~3°,the drag of the cavity is obviously larger under the condition of engine ignition.It would make a great difference to the further design of round scramjet combustor.