面搭接嵌套网格及其对变前掠翼性能的计算

Nested grids using patched-grid generation technique and characteristics computation of variable forward-swept wing

为快速高效地计算变前掠翼开裂式方向舵的操纵性能,建立了一种基于面搭接技术的嵌套网格剖分方法,并通过面积加权法建立搭接面两侧的通量守恒关系。然后采用N-S控制方程的有限体积法离散格式,选取SST湍流模型,对襟翼下偏30°的NACA 23012翼型的升阻特性进行数值计算,并与常规分块网格下的数值结果和风洞试验结果作了比较。验证表明:嵌套网格与常规网格的马赫数云图基本一致,襟翼上表面气流分离位置一致,并且均能捕捉到主翼型下端有形成涡的趋势;面搭接及面积加权法能够保证通量守恒传递和计算的精度,该方法简单、便捷,效率较高。最后,采用面搭接技术对变前掠翼开裂式方向舵的升阻特性进行了计算,前掠翼机翼气流流动由翼尖指向翼根,避免翼尖提前失速导致操纵效率急剧下降,面搭接嵌套网格计算方法在变前掠翼性能计算中应用良好。结果表明该方法是操纵面性能计算的一种高效方法。

In order to efficiently predict the controllability of split rudder with Variable Forwards Swept Wing （VFSW）efficiently,a nested grids method using patched-grids generation technique was developed. The flux conservation on both sides of the interface was established by air-weight mean method.N-S equa-tion,as the governing equation,were solved numerically using finite volume method with SST turbulence model.The lift-drag ratio of airfoil NACA 23012 with wing flap deflection of 30°was simulated,whose re-sults were compared with those in normal block grids,as well as those of wind tunnel experiments.The ex-ample showed that the Mach cloud picture and the separation point position of airflow on upper surface of wing flap of nested grids are the same with that of common grids.Both have the trend to genverate a vortex under the airfoil.The patched-grid generation technique and air-weight mean method ensured the flux con-servation transmission and computational precision,which is simple,convenient and efficient.Finally,the lift-drag ratio of split rudders in VFSW configuration was computed,and the airflow moved from wing tip to wing root on forwards swept wing,which avoided a sharp decline in control efficiency caused by losing speed about wing tip in advance.The nested grids method using patched-grids generation technique worked well in the calculation of VFSW performance and the results showed the nested grids method had a high efficiency in control surface design and performance computation.