基于广义Richardson外插方法的颤振模拟耦合时间精度研究

为更准确地评估颤振问题时域模拟在实际计算中表现出的时间精度,采用不同精度的耦合方法对Isogai Wing和AGARD 445.6 Wing的颤振问题进行时域模拟。参照网格收敛性分析方法,提出了基于广义Richardson外插方法的颤振问题时域模拟耦合时间精度分析方法,分析时域计算结果的时间步长收敛性,计算数值模拟结果时间精度并获得时间步长无关解。分析表明,对于Isogai Wing和AGARD 445.6 Wing颤振问题,计算结果具有良好的时间收敛性,采用广义Richardson外插方法对各耦合方法分析所得精度与理论分析结果基本一致。在合适的时间步长区间内,可忽略具体时间步长选取对广义Richardson外插方法分析结果的影响,验证了提出的气动弹性模拟耦合时间精度分析方法。

On time domain accuracy of flutter simulations based on generalized Richardson extrapolation method

To evaluate the time domain accuracy of flutter simulations,three coupling methods,i.e.,loose coupling method,improved loose coupling method and tight coupling method,are used to simulate Isogai Wing and AGARD 445.6 Wing models fluttering in the time domain.In analogy to the grid convergence analysis,a time accuracy analysis approach based on the generalized Richardson extrapolation method for time domain flutter simulations is proposed,with which the time convergence and accuracy analysis of flutter boundary simulations in the time domain is performed,and the time discretization independent result is obtained.The analysis shows that time domain simulation results of both Isogai Wing and AGARD 445.6 Wing flutter have good time convergence.The time accuracy obtained by generalized Richardson extrapolation method is basically consistent with that of the theoretical analysis.Within an appropriate time step range,the influence of time step selection for the analysis can be neglected.The present study suggests that it is feasible to establish a time accuracy analysis method based on the generalized Richardson extrapolation method for flutter simulations in the time domain.