排气扩压器对TBCC排气系统的流道性能影响研究

Effects of Exhaust Diffuser on Flow Path Performance of TBCC Exhaust System

关键词:  排气扩压器  单边膨胀组合喷管  推力测量  风洞试验  推力系数

Key words:  Exhaust diffuser  Single expansion combined nozzle  Thrust measurement  Wind tunnel test  Thrust coefficient

摘要:

为了研究不同的排气扩压器（简称排扩）直径、排扩形状以及排扩与单边膨胀组合喷管模型之间的相对位置对缩比喷管试验推力测量的影响，对3种排扩在不同的长径比下，进行了共6组风洞试验，同时对相应工况进行了数值模拟，并将试验与数值计算结果进行比较。研究结果表明：排扩的形状对喷管测力影响很小；大直径的排扩2的距离变化对测得的推力系数基本没有影响，但小直径的排扩1在排扩入口与喷管出口齐平工况下测得的推力系数明显小于喷管伸入排扩工况；在喷管模型伸入排扩工况下，排扩的直径对喷管测力基本无影响，但是在喷管出口与排扩入口齐平的工况下，使用小直径的排扩1会使测得的推力系数偏小。因此，排扩的几何参数变化对喷管外壁面的边界层流动影响很小，在排扩对喷管出口流场产生雍塞时，会影响喷管的推力测量。

Abstract:

In order to study the effects of different exhaust diffuser diameters， exhaust diffuser shapes， and the relative position between exhaust diffuser and single expansion combined nozzle models on the thrust measurement of reduced ratio nozzles， a total of 6 sets of wind tunnel tests have been carried out on 3 types of exhaust diffuser at different length-to-diameter ratios. At the same time， a numerical simulation was carried out on the corresponding working conditions， and the results of the experiment and the numerical calculation were compared. The results show that the shape of the exhaust diffuser has little effect on the thrust measurement of the nozzle. The distance change of the large diameter exhaust diffuser 2 has basically no effect on the measured thrust coefficient， but the measured thrust coefficient by the small diameter exhaust diffuser 1 when the nozzle outlet is aligned with exhaust diffuser inlet is significantly smaller than that of the nozzle extended into exhaust diffuser conditions. When the nozzle model is extended into the exhaust diffuser， the diameter of the exhaust diffuser basically has no effect on the nozzle thrust measurement， but when the nozzle outlet is aligned with the exhaust diffuser inlet， the use of a small diameter exhaust diffuser 1 will make the measured thrust coefficient smaller. Therefore， the change of geometrical parameters of the exhaust diffuser has little effect on the boundary layer flow on the outer wall of the nozzle. When the exhaust diffuser produces a blockage on the nozzle outlet flow field， it will affect the thrust measurement of the nozzle.