一种改进的跨声速旋成体壁面脉动压力经验预测公式

Improvement of the Fluctuating Pressure Empirical Functions for a Body of Revolution at Transonic Mach Numbers

使用大涡模拟(LES)方法对典型整流罩旋成体结构进行非定常数值模拟研究,结果表明引起壁面压力脉动的流场结构随时间和空间变化,不同的流场结构之间相互干扰。同时研究发现,旋成体折角膨胀会造成流动在较短的距离内迅速加减速,同样引起壁面压力脉动。基于上述流动现象,重新划分压力脉动产生区域,通过引入空间修正项,提出一套改进的跨声速旋成体壁面脉动压力经验公式。算例表明,该方法能够显著提高旋成体在跨声速条件下的脉动压力分布的预测精度。

The transonic buffet environment around a generic rocket fairing has been numerically investigated by the large-eddy simulation （LES） method. It is found that the flow structures generating the fluctuating wall pressure vary temporally and spatially, and also interact with each other. In particular, serious buffet environment could also be induced by the expansion fan, where significant flow acceleration and deceleration occur. Accordingly, the flow regions are redefined, and the corresponding empirical functions are proposed. By introducing the spatially-correlated corrections, the accuracy of the modified functions are remarkably improved, especially at the locations after the separation bubble.