谐波平衡法数值模拟周期性非定常流动

Numerical simulation of periodic unsteady flow by harmonic balance method

谐波平衡法是目前非定常流动数值研究中颇受关注的频域计算方法,该方法计算效率高,特别是对于周期性非定常流动问题具有明显的计算优势。采用谐波平衡法数值模拟高超声速导弹标模模型在不同参数下的强迫俯仰振动,重建气动力/力矩系数迟滞曲线,将计算结果与时域方法相比较,详细考察谐波平衡法的计算精度、效率和内存需求,分析不同参数对谐波平衡法计算的影响。计算结果表明,谐波平衡法适用于中小振幅下的非定常流动计算,且计算时间基本不受减缩频率的影响,对于长周期低频问题,较时域方法有明显计算优势。

The harmonic balance method is one of the computational methods in frequency domain with a high computational efficiency,which has won special attention in present numerical studies of unsteady flow,and it has an obvious advantage especially for periodic unsteady flow problems. A harmonic balance method was used to simulate the forced pitching oscillation of the HBS（ hyper ballistic shape） in different conditions,and then the coefficient of force and moment versus angle of attack were rebuilt. A comparison was made with the time domain method to investigate the performance of the harmonic balance method. Results show that the harmonic balance method is applicable to simulate middle and small amplitude pitching,and the computing time won ＇t be effected by the frequency. Therefore,the harmonic balance method has obvious advantage for problems with a long period.