【作者】 肖天航； 昂海松； 周新春；

【Author】 Xiao Tianhang Ang Haisong Zhou Xinchun (Micro Air Vehicle Research Center,Nanjing University of Aeronautics and Astronautics,Nanjing 210016,China)

【机构】 南京航空航天大学微型飞行器研究中心；

【摘要】 将预处理引入到 ALE 格式的非定常可压缩 N-S 方程中,发展了一种能有效模拟大幅度边界运动的非定常流场的数值方法。控制方程在非结构的动态网格上用双时间步推进并用隐式、LU-SGS 迭代求解;双重 Delaunay 图映射的网格变形技术和非结构嵌套网格方法结合使用,解决既有整体大幅运动,又有局部柔性变形的复杂运动边界问题。扑翼应用实例的结果表明,该方法将可压缩漉方法的计算能力拓展到了低马赫数范围,用于计算大幅度非定常流场能得到满意的计算精度和效率。更多还原

【Abstract】 In this paper,an effective solution method to perform simulations for unsteady flows with large boundary movement is developed using the governing equations of compressible fluids on unstruc- tured dynamic meshes.The method is based on a dual time-stepping scheme in conjunction with low Mach number preconditioning and an implicit LU-SGS iteration.Also,a strategy which combines mesh deformation based on Delaunay graph mapping and unstructured overset grids is proposed for sim- ulating unsteady flows both with large flapping motion and with small deformation.The results d sever- al typical test cases indicate that this algorithm provides satisfactory accuracy and efficiency for low- Beynolds-number unsteady flows of flapping-wings.更多还原