非轴对称前涵道引射器性能的数值研究

Numerical Investigation for Performance of Non-Axisymmetric Front Variable Area Bypasses Injector

关键词:  非轴对称前涵道引射器  轴对称前涵道引射器  热混合效率  引射系数  总压恢复系数

Key words:  Non-axisymmetric FVABI  Axisymmetric FVABI  Thermal mixing efficiency  Ejector coefficient  Total pressure recovery coefficient

摘要:

以轴对称前涵道引射器为基础，提出了一种非轴对称前涵道引射器方案。为了比较非轴对称和轴对称前涵道引射器在热混合效率，引射系数和总压恢复方面的不同，采用数值模拟的方法对不同掺混角度和进出口压比的模型进行了计算，并得到引射器的性能参数变化规律。结果表明，在开口面积不变的情况下，增大气流的掺混角度会使前涵道引射器的热混合效率降低，总压恢复系数减小，引射系数也有较大的减小；在亚临界时，随着进出口压比的增大，引射器的热混合效率和总压恢复系数逐渐变大，引射系数则会减小，并且相同条件下，非轴对称前涵道引射器与轴对称前涵道引射器相比，热混合效率提高，总压恢复系数和引射系数分别会减小大约2%和20%。

Abstract:

The concept of non-axisymmetric forward variable area bypass injector (FVABI) was proposed based on the structure of axisymmetric FVABI. To compare the thermal mixing efficiency，ejector coefficient，total pressure recovery coefficient of non-axisymmetric FVABI with axisymmetric FVABI，a series of numerical simulation were conducted based on the non-axisymmetric and axisymmetric FVABI with variation of the mixing angle，inlet to exit pressure ratio and the principle of effects on the performance was obtained. The results show that the thermal mixing efficiency，total pressure recovery coefficient and ejector coefficient of FVABI decrease with the increasing mixing angle when the exit flow area of first bypass is constant. In subcritical condition，there is a decrease in ejector coefficient and an increase in both of thermal mixing efficiency and total pressure recovery coefficient when the inlet to exit pressure ratio increases. The thermal mixing efficiency of non-axisymmetric FVABI is higher than that of axisymmetric FVABI under the same conditions. The total pressure recovery coefficient of non-axisymmetric FVABI decreases by 2%，while ejector coefficient reduces 20% as compared with axisymmetric FVABI.