摘要
通过求解粘性非定常可压缩N-S方程,发展了旋翼/机身气动干扰的数值模拟方法,主要技术措施包括:(1)通过ADT数据结构,建立了高效的多块对接网格动态重叠技术;(2)在可压缩方程求解中引入低速预处理方法,克服低速流场求解时的刚性问题;(3)加入了多重网格方法,提高收敛效率;(4)湍流模型方程求解需要反复计算壁面最近距离,采用Wigton的优化算法很大程度上提高了计算速度。利用建立的计算方法对佐治亚大学(GIT)旋翼/机身干扰模型进行了数值模拟,分别比较了机身表面的平均压力分布、旋翼的下洗流场以及非定常压力脉动,对干扰现象及其流动机理进行了分析。
Viscous,unsteady compressible N-S equations and moving overset grid methodology are adopted for the numerical simulation of rotor airframe interaction,and some improvements are proposed to improve the efficiency and accuracy.These modifications include:(1)low speed preconditioning are implemented in the solution of compressible equations to overcome the stiffness when solved in incompressible regions;(2)multigrid methods are used to speed up the convergence;(3)the nearest distances from any cell to wall are calculated repeatedly because of grids moving,Wigton's optimized methods are implemented to deal with the difficulties.GIT rotor/airframe interactions are simulated by the methods,the averaged surface-pressure distributions on the airframe,the down wash velocities and pulsed pressure are compared with experimental values,the interaction phenomena and vorticity patterns that impinge on the airframe are analyzed.
出处
《直升机技术》
2007年第3期4-10,共7页
Helicopter Technique
关键词
旋翼/机身干扰
压力分布
旋涡
低速预处理
多重网格
rotor/airframe interaction
CP distribution
vortex
low speed preconditioning
multigrid
