分流板与侧壁缝隙对TBCC排气系统性能影响研究

Influence of gap between splitter plate and side wall on performance of TBCC exhaust system

为研究涡轮基组合循环(TBCC)排气系统的分流板与侧壁之间的缝隙对其性能的影响,利用数值仿真方法研究不同缝隙长度和宽度下喷管性能参数变化规律,针对涡轮通道和冲压通道在不同工作状态下有无缝隙对喷管性能的影响进行研究。结果表明,在喷管双通道均为欠膨胀状态时,分流板与侧壁之间存在缝隙漏气的情况下,对于漏出气体的涡轮通道,随着缝隙长度的增加,其推力系数下降、升力增加,而冲压通道推力系数几乎无变化,但升力增加。缝隙宽度变化对喷管性能的影响与长度的影响规律一致。此外,通过对不同喷管工作状态的研究发现,缝隙的存在会降低推力系数,缝隙的相对宽度为0.033、相对长度为0.31时,2.8%的漏气量能造成超过1%的推力系数的损失。

In order to study the influence of the gap between splitter plate and side wall of a turbine-based combined cycle(TBCC)exhaust system on its performance,the numerical simulation method was used to analyze the influence of different gap lengths and widths on the performance parameters of the nozzle.Then,the influence of whether there was a gap between the turbine channel and the stamping channel under different working conditions on the nozzle performance was studied.The results show that when two channels of the nozzle are under-expanded,there is a gap between splitter plate and side wall.For the turbine channel with gas leakage,the thrust coefficient of the turbine channel decreases,and the lift increases with the increase in the gap length,while the thrust coefficient of the stamping channel has almost no change,but the lift increases.In addition,the influence of gap width change on nozzle performance is consistent with that of length.The research on different nozzle working conditions finds that the existence of gaps always reduces the thrust coefficient.When the relative width and length of the gap are 0.033 and 0.31,2.8%of the gas leakage can cause more than 1%loss of the thrust coefficient.