着陆襟翼打开状态下抓斗式反推装置三维流动数值模拟

基于求解三维Reynolds-averaged Navier-Stokes方程,数值模拟了着陆襟翼打开状态下抓斗式反推装置工作时流场分布特性.网格采用非结构化四面体与六面体混合分区生成技术,湍流模型选用Spalart-Allmaras模型.结果表明,在计算滑跑速度范围内,反向排气流不会被进气道重新吸入;高温反向排气流会冲击到飞机吊挂及部分机翼,需引起注意;随着滑跑速度的降低,反向排气流侧向影响范围急剧增大,若机翼后掠角较大,则反向排气流容易被相邻发动机再次吸入,引起进气畸变;当滑跑速度降低到34m/s时,反向流开始吹向地面,可能会卷起地面颗粒物并且被进气道吸入;随着滑跑速度的降低,反推力减小. 

Numerical simulation on flow field of the clamshell thrust reverser with landing flap deployed

Computational Fluid Dynamics (CFD) technology was used to investigate the flow field distribution characteristic of a clamshell thrust reverser with flap deployed while landing. The computational grid was generated with unstructured tetrahedron and hexahedron meshes, and S-A turbulent model based on solving Reynolds-averaged N-S equations was adopted. The results show, in the range of landing speed between 136.1m/s and 17.0m/s, the hot reverse exhaust flow from the clamshell thrust reverser is not re-injected into the engine inlet, but it impinges on part of the aerofoil and pylon. As landing speed decreases, the hot reverse exhaust flow spreads forward and laterally deeper, so it may be re-injected by near engine inlet if the aerofoil sweepback is large enough, which will result in inlet distortion. When landing speed decreases down to 34m/s, the hot reverse exhaust flow starts to impinge on the ground, which may wind up some dross to the inlet. At last, the reverse thrust decreases as landing speed decreases.