基于网格速度法的非定常流场模拟和动导数计算  

An Effective Computation Method Based on Field Velocity Approach for Unsteady Flow Simulation and Obtaining Dynamic Derivatives

作　　者：郭东[1] 徐敏[1] 陈士橹[1] 

机构地区：[1]西北工业大学航天学院,陕西西安710072

出　　处：《西北工业大学学报》2012年第5期784-788,共5页Journal of Northwestern Polytechnical University

基　　金：国家自然科学基金重大研究计划(90816008);教育部博士点基金(20070699054)资助

摘　　要：基于网格速度法的思想,将迎角的突变和俯仰角速率的突变叠加起来,发展了一套在固定网格上模拟飞行器俯仰振荡非定常流场的方法,该方法不需要实时更新网格,减少了计算时间和所需内存,避免了负体积的出现。首先计算了NACA 0006的阵风响应和NACA 0012翼型的俯仰振荡,所得结果与实验值和动网格方法符合较好,这表明该方法能够准确模拟此类非定常问题;最后将该方法应用于国外动导数计算标模Basic Finner Missile(BFM)俯仰振荡运动的数值模拟,并计算了其在马赫数1.58～2.5的静、动稳定性导数,计算结果与风洞实验值基本吻合,体现了该方法的正确性。Sections 1 through 3 of the full paper explain and evaluate the computation method mentioned in the title, which we believe is effective. Their core consists of： the field velocity or grid velocity approach provides a unique methodology for directly calculating aerodynamic responses to step change in flow conditions; the grid time metrics include the velocity caused by the impulsive change in angle of attack but the mesh is not moved accordingly; this approach avoids numerical instabilities and decouples the step change in the angle of attack from a pitch rate ; based on this approach, a technique is presented to model longitudinal unsteady flow phenomenon by superposing the step change in the angle of attack upon the impulsive change in pitch rate. In Figs. 4 and 5, numerical results are validated by comparison with experimental results for NACA 0012 airfoil under forced oscillations. To validate further the applicability for the present method, pitch damping derivatives, calculated from the load history of the unsteady flow around a standard research configuration, known as the Basic Finner Missile, are presented in Figs. 10 and 11. Predicted results show indeed good agreement with available wind tunnel data.

关 键 词：计算流体力学 非定常流场 网格速度法 动导数 

分 类 号：V211.3[航空宇航科学与技术—航空宇航推进理论与工程]