基于CFD/CSD耦合的火箭跨声速气动阻尼特性分析

Characterization of Transonic Aerodynamic Damping of Rockets Based on CFD/CSD Coupling

随着新型大推力火箭的发展,弯曲模态频率的不断降低,以及流动分离和跨声速飞行时产生的激波震荡等因素,其在跨声速飞行过程中更容易出现非定常振动发散。文章以某带助推的运载火箭模型为研究对象,通过数值计算获取火箭强迫振动时的气动阻尼,并对影响火箭气动阻尼的因素进行了分析。包括结构节点位置、振动振幅大小、脉动压力等。研究表明:助推主要起到增大气动阻尼的作用;前节点主要影响收缩段的气动阻尼;振动振幅大小和脉动压力对气动阻尼的影响可忽略不计。

With the development of new high-thrust rockets,the decreasing frequency of the bending modes of the rocket,as well as the factors such as flow separation and shock oscillations generated during transonic flight make it more prone to non-constant vibration.In this paper,a launch vehicle model with boost was taken as the research object,and the aerodynamic damping of the rocket during forced vibration was obtained through numerical calculation.The factors affecting the aerodynamic damping of the rocket were analyzed,including the position of structural nodes,the magnitude of vibration amplitude,pulsating pressure and so on.The study shows that the boost mainly plays the role of increasing aerodynamic damping and the front node mainly affects the aerodynamic damping of the contraction section.The vibration amplitude size and the pulsating pressure have a negligible effect on the aerodynamic damping.