基于壁面压力的试验参数分析方法

Parameter Extracting Method Based on Wall Pressure

关键词:  超燃冲压发动机  试验参数  参数分析方法  燃烧效率  数值计算  壁面压力

Key words:  Scramjet  Experimental parameter  Parameter extracting method  Combustion efficiency  Numerical simulation  Wall pressure

摘要:

为了在冲压发动机试验过程中丰富试验参数类别和提高参数分析速度，针对直连式超燃冲压发动机，原创性地提出了基于壁面压力测量结果的试验参数分析方法。该方法引入原子流量守恒方程构建了封闭方程组，在无需任何额外测量仪器的条件下，以壁面压力、来流参数和燃烧室面积变化律为输入，求解方程组可快速获得超燃冲压发动机的马赫数、温度、速度、组份浓度、燃烧效率等参数。结合三维数值计算和地面试验，通过两个算例对该方法的可行性进行了验证。结果表明，该算法可以获得较高的精度，在燃烧室出口，速度、温度等误差均在5%以内，组份浓度分布和数值结果非常吻合。

Abstract:

To enrich the analyzing data and increase the analyzing efficiency in scramjet experiments， a parameter extracting method based on wall pressures for direct connected scramjet was developed. With only tested wall pressures and no other measured parameters， the method can obtain all important parameters on line such as Mach number， temperature， velocity， species mass fraction， combustion efficiency and so on by solving a set of six equations which consists of atom flux conservation equations， state equation of idea gas and energy conservation equation. The method was tested and verified by 3D numerical simulations and experiments of two direct connected scramjets. The errors of velocity and temperature at the exit of combustor are both within 5%， and the species mass fractions agreed well with the CFD results.