在双下侧冲压发动机地面连管试验中发现实测推力与一维流计算数据相差较大,为探究差异根源,以数值仿真为基础,对比分析了补燃室中均匀流场和非均匀流场对冲压喷管推力特性的影响。分析结果表明,流场的非均匀性导致计算截面上的实际滞止参数与理论计算数据有差异,因此,在这种条件下,不能直接利用一维流理论进行计算;同时,文中在仿真及试验基础上给出了非均匀性对推力影响的工程估算方法。

The thrust of a ramjet measured in the direct-connected experiment was obviously different from the thrust based on 1D theoretical calculation, to analysis the cause of above phenomenon, the research on the effect of uniformity of flow field on thrust was conducted on the basis of 3D numerical simulation, the results show that the uniformity of flow field makes a obvious difference between the results by 3D simulation and the results by 1D theoretical calculation on the stagnation parameters in key section of ramjet. Therefore, the thrust acquired by 1D theoretical calculation is incorrect under the condition that flow field is uneven. Furthermore the method to predict the effect of uniformity of flow field on thrust is presented.