一种基于流管收缩比分析超声速进气道临界性能的方法

Method Based on Capture Stream Tube Contraction Ratio Analysis of Supersonic Inlet Critical Performance

关键词:  超声速进气道  总收缩比  流量系数  总压恢复系数 

Key words:  Supersonic inlet  Inlet contraction ratio  Mass-flow coefficient  Critical total pressure recovery coefficient

摘要:

为研究进气道临界总压恢复系数与主要几何特征之间的联系,通过零维流动分析,提出了一种基于流管收缩比计算临界总压恢复系数的理论公式,并与通常采用的基于喉道参数的计算方法进行对比分析,阐述了两种计算方法的不同物理意义。该公式表明,进气道临界总压恢复系数等于流管收缩比、函数K(Ma_th)及Q(Ma∞)三项乘积。研究了计算公式中各变量对临界总压恢复系数的影响,分析表明流管收缩比是决定临界总压恢复系数的重要变量。在大多数情况下,流管收缩比与临界总压恢复系数具有正相关的变化规律。 

Abstract:

In order to study the link between critical total pressure recovery coefficient and the main geometric feature of supersonic inlet, a new formula of calculating critical total pressure recovery coefficient of supersonic inlet based on the 0-D gas dynamic theory was proposed. The term of ‘capture stream tube contraction ratio’ defined as the massflow coefficient times the contraction ratio was used in the new formula. Difference between the new formula and the method of using the air flow parameters of throat calculating critical total pressure recovery coefficient was analyzed. The present paper has investigated the different physical meaning of two methods. In new formula, total pressure recovery coefficient is the product of capture stream tube contraction ratio, function K(Ma_th) and function Q(Ma∞).Effects of the terms in new formula on critical total pressure recovery coefficient were studied. Analysis shows that capture stream tube contraction ratio plays an important role in determining the critical total pressure recovery coefficient. In most cases,critical total pressure recovery coefficient and capture stream tube contraction ratio show positive correlation. 