导弹纵向俯仰气动特性数值分析

Numerical Investigation of Unsteady Aerodynamic Characteristics of a Pitching Missile

应用有限体积方法求解三维可压缩雷诺平均N-S方程,计算了某型巡航导弹的静、动态绕流流场和空气动力特性。湍流模型应用修正后的B-L代数湍流模型。以细长旋成体绕流流场为例进行数值计算,并和实验数据相比较,验证了本文方法的可靠性,在此基础上,开展了某型巡航导弹绕不同转轴和以不同频率进行俯仰振动的非定常气动力迟滞特性研究。计算结果表明,当导弹作快速俯仰振动时,在上仰和下俯过程中的同一迎角瞬间,绕导弹流场流动明显不同,表现出明显的非定常迟滞特性。并且,导弹的非定常气动力迟滞特性随振动频率的增大变化明显,且气动力迟滞曲线随着振动轴位置的变化而变化。

Three dimensional Reynolds averaged Navier-Strokes numerical simulations were carried out to predict the flowfield characteristics of a winged missile based on the finite volume method. Baldwin-Lomax eddy viscosity model with the modifications suggested by Degani and Schiff was used here. The computational results of the aerodynamic loads of a slender revolution body were given, and well agree with experiment data. The unsteady aerodynamics about a winged missile, which is oscillated in pitching with different frequencies and different oscillating positions are also shown. The properties of unsteady aerodynamics in these cases were researched here. It finds that from the computational results, the unsteady hysteresis of the lift, drag and pitch moment coefficients vary significantly not only with the frequency, but also with the position of oscillating axis when the missile pitches very fast.