考虑多种物理效应的钝锥俯仰稳定性参数影响分析

摘要

The pitching dynamic derivative of blunted conical models in hypersonic flow has been validated by using implicit scheme,with the technology of the dual time stepping,rigid rotary grid deformation and least square identification method.The same methods and blunt cone model are also applied to compare the influence of the pitching dynamic derivative with different altitudes,rarefied effect and chemical non-equilibrium effect.The results indicated that accurate calculation of the aircraft pitch dynamic derivative under the condition of high altitude and high Mach number should consider the chemical non-equilibrium effect and rarefied effect.These physical effects will affect vehicle static and dynamic stability degree directly.%首先采用二阶ROE格式计算了非定常NS方程下高超声速钝锥体的俯仰阻尼导数,通过与文献中内伏牛顿法和实验结果对比验证了本文所采用非定常计算方法的正确性.同时采用二阶ROE格式及双时间步长、刚性旋转动网格技术等,数值分析了NS方程计算条件下高空高马赫数钝锥体模型的强迫振动非定常流场特征,并运用最小二乘法辨识出其俯仰静稳定性导数与俯仰阻尼导数.通过计算结果对比分析了不同高度(含稀薄气体效应)、Maxwell滑移边界条件及五组元化学非平衡模型对钝锥体模型非定常流动特征及静、动导数的影响.结果分析表明,本文所计算的钝锥模型在所假设强迫振动下的俯仰稳定性参数随高度变化剧烈,且考虑滑移边界条件与化学反应会使得俯仰力矩迟滞曲线形态发生较大程度改变.准确计算高空、高马赫数条件下飞行器俯仰阻尼导数应考虑化学非平衡效应和稀薄气体效应的影响,是否考虑这些物理效应会关系到飞行器静、动稳定的程度.