前缘钝化和化学非平衡效应对斜爆震发动机进气道特性的影响

Influence of Leading Edge Blunt and Chemical Non-Equilibrium Effect on Characteristics of Inlet of Oblique Detonation Engine

关键词:  斜爆震发动机  进气道  前缘钝化  化学非平衡效应  温度边界层  工作性能

Key words:  Oblique detonation engine  Inlet  Leading-edge blunt  Chemical non-equilibrium effect  Temperature boundary layer  Working performance

摘要:

为了探究前缘钝化、化学非平衡效应对斜爆震发动机进气道的工作性能及出口温度边界层分布的影响，采用热完全气体、化学非平衡气体两种模型对顶板、唇口前缘不同钝化半径下斜爆震发动机进气道进行数值模拟。结果表明：相比基准进气道，钝化后进气道出口唇口板侧温度边界层较厚，顶板侧温度边界层较薄；在化学非平衡气体模型下，顶板前缘钝化半径R₁≥4mm时进气道顶板附近分离区内离解反应较为明显，氧气的最高离解度约为10.9%；唇口前缘钝化半径R₂≥2mm时进气道的唇罩、唇口板附近离解反应较为明显，氧气的最高离解度约为15.2%；当钝化半径≥4mm时，两种气体模型下进气道出口总压恢复系数和静温的相对变化量绝对值均大于0.5%，有必要考虑化学非平衡效应对进气道出口性能的影响。

Abstract:

In order to explore the influence of leading-edge blunt and chemical non-equilibrium effect on the working performance and the outlet temperature boundary layer distribution of the oblique detonation engine inlet， two models of thermally perfect gas and chemical non-equilibrium gas were used to simulate the inlet of oblique detonation engine with different blunting radius of leading edge in top plate and lip. The results show that compared with the basic inlet， the temperature boundary layer of lip plate side at the exit of the blunted inlet is thicker， and the temperature boundary layer of top plate side at it is thinner. Under the chemical non-equilibrium gas model， the dissociation reaction in the separation zone near the top plate of the inlet is more obvious when the blunting radius of leading-edge in top plate R₁ ≥ 4mm， the maximum dissociation degree of the oxygen is about 10.9%. The dissociation reaction is more obvious near the lip mask and lip plate of inlet when the blunting radius of lip leading-edge R₂ ≥ 2mm， the maximum dissociation degree of the oxygen is about 15.2%. When the blunting radius is not less than 4mm， the absolute value of the relative change of total pressure recovery coefficient and static temperature at the exit of inlet under the two gas models are both greater than 0.5%. It is necessary to consider the influence of the chemical non-equilibrium effect on performance at exit of inlet.