基于正激波位置计算的进气道/发动机系统实时仿真模型

研究了超声速条件下,基于进气道内正激波位置计算的进气道/发动机系统综合仿真问题。提出了将超声速进气道分为内、外两部分独立计算的方案,外部通过斜激波计算公式获得进气道内部的边界条件,对进气道内部采用准一维CFD模型模拟背压对正激波位置的影响。相比二维CFD计算,在保证参数精度要求的前提下有效缩短了计算时间,提高了仿真实时性。进一步将进气道模型与发动机部件级模型匹配运行,构建了进气道与发动机综合实时仿真模型。进气道/发动机综合模型的仿真表明,其能够准确模拟进气道正激波位置对涡扇发动机的动稳态影响,当来流发生扰动时,通过喷管喉道面积和压缩部件导叶角的快速调节,能够抑制正激波位置的变化,并使推力下降量减少50%。 

Real time simulation modeling for integrated inlet and engine system based on normal shock position calculation

An integrated simulation for mixed compression supersonic inlet and engine system was conducted based on normal shock position calculation. A computation scheme was put forward to separate the inlet model into two parts, which were calculated respectively: the external part of the formula was used to compute the oblique shock to obtain internal inlet boundary conditions, and the internal part modelling by quasi one dimensional CFD was used to simulate the effect of back pressure on the normal shock position. Compared with two dimensional CFD simulation, it was found that this method can shorten the calculation time a lot on the premise of guaranteeing parameter accuracy effectively, resulting in a better real time simulation ability. Further, the inlet model and engine component level model were integrated to output dynamic coupling effects of these two systems. Finally, some necessary simulations were implemented, showing clearly that the integrated model could accurately emulate the dynamic and static influences between inlet norm shock position and the engine. When turbulence occurred in the incoming flow, the change of the normal shock position can be suppressed by adjusting the nozzle throat area and the compressor guide vane angle rapidly. The reduction of the thrust can be reduced by 50%.