非对称波瓣上外扩张角对S弯二元喷管性能影响

Effects of Upward-Outward Penetration Angle of Asymmetric Lobed Mixer on Aerothermodynamic Performance of an S-Shaped Two-Dimensional Nozzle

关键词:  S弯二元喷管  非对称波瓣  上外扩张角  热混合效率  总压恢复系数  壁面最高温度

Key words:  S-shaped two-dimensional nozzle  Asymmetric lobed mixer  Upward-outward penetration angle  Thermal mixing efficiency  Total-pressure recovery factor  Maximum wall temperature

摘要:

为了明确非对称波瓣上外扩张角对涡扇发动机S弯二元喷管流场、流向涡涡量场、热混合效率、总压恢复系数和壁面最高温度的影响，采用基于 Navier-Stokes(N-S)方程的三维数值模拟方法对不同非对称波瓣上外扩张角模型进行了定量研究，并得到了气动热力性能的影响规律。结果表明:非对称波瓣上外扩张角在5°～25°变化时，在波瓣尾缘处，流向涡的无量纲涡量随上外扩张角的增大而增大。在S弯二元喷管出口截面处，热混合效率随上外扩张角的增大而增大，总压恢复系数随上外扩张角的增大呈现出增大-减小-增大的趋势。S弯二元喷管的壁面最高温度随上外扩张角的增大先下降后升高，其中上外扩张角为10°壁面温度最低，约为426K。

Abstract:

In order to clarify the effects of upward-outward penetration angle of asymmetric lobed mixer on flow field，streamwise vorticities，thermal mixing efficiency，total-pressure recovery factor and maximum wall temperature of the turbofan S-shaped two-dimensional nozzle，quantitative study on different upward-outward penetration angle of asymmetric lobed mixer was carried out through the three dimensional numerical simulation based on Navier-Stokes equations，and the principle of effects on aerothermodynamic performance was obtained. The results show that，when upward-outward penetration angle of asymmetric lobed mixer varies from 5° to 25°，non-dimensional streamwise vorticities increase at the trailing edge of the lobed mixer with the growing upward-outward penetration angle. At the exit section of the S-shaped two-dimensional nozzle，thermal mixing efficiency augments as the upward-outward penetration angle increases，and the total-pressure recovery coefficient has the trend of increasing，decreasing and increasing again. The maximum wall temperature of the S-shaped two-dimensional nozzle firstly decreases，and then increases with the growing upward-outward penetration angle，while the minimum wall temperature is at 10°，about 426K.