二维超声速进气道扩张段性能计算

Performance calculation of two-dimensional supersonic inlet diffuser

研究了一种二维超声速进气道扩张段型面的中心线变化规律、扩张比及中心线偏距对设计状态下进气道的气动性能及流场的影响。结果表明:采用前缓后急中心线变化规律的进气道出口总压恢复系数最高,而采用前急后缓中心线变化规律的进气道总压恢复系数最低;随着扩张比从1.40增大到1.80,进气道总压恢复系数和抗反压能力均下降,出口马赫数上升,扩张比与长度对进气道出口参数的影响存在较强的耦合关系;随着偏距比的增加,进气道总压恢复系数起初有一定的升高,但偏距比增大到0.80之后,总压恢复系数降低,出口马赫数增大,总体上偏距比变化对进气道抗反压能力影响不大。

The influences of the law of centerline variation, expansion ratio and centerline offset of two-dimensional supersonic inlet diffuser on aerodynamic performance and flow characteristics under inlet design condition are studied. The numerical results indicate that the inlet with diffuser rapid turning at its exit has maximum total pressure recovery coefficient and inlet with diffuser rapid turning at the entrance has minimum total pressure recovery coefficient; as the expansion ratio increases from 1.40 to 1.80, inlet total pressure recovery coefficient and backpressure-resistance ability decrease, and the exit Mach number increase; the effect of expansion ratio and length on inlet exit parameter has a strong coupling relationship. As offset ratio increases, the inlet total pressure recovery coefficient increases at the beginning, but as the offset ratio increases to more than 0. 80, the inlet total pressure recovery coefficient declines and the exit Mach number increases. General speaking, the variation of offset ratio has little effect on backpressure-resistance ability of the inlet.