通过耦合求解非定常Euler/Navier-Stokes方程和单自由度滚转运动方程,对带副翼偏转的65°后掠角尖前缘三角翼WI1-SLE自由滚转运动进行了研究,Navier-Stokes方程的求解采用基于Spalart-Allmaras湍流模型的脱体涡模拟(DES)。在多块结构网格上,应用基于弧长的无限插值理论(TFI)生成变形网格,实现副翼偏转,而三角翼的滚转运动则通过网格的整体旋转实现。结果表明:Euler方程和DES方法均准确地模拟出了三角翼在滚转运动过程中存在的3个平衡位置。出现平衡位置的原因分别是:①流动对称性;②机翼左侧发生涡破裂的分离涡与右侧分离涡相互平衡使得滚转力矩为0,并且平衡位置仅与三角翼两侧涡强的差有关;③副翼偏转和左右机翼不对称分离涡涡强差产生的滚转力矩相互平衡。此外,滚转运动对副翼偏角幅值很敏感,幅值的微小改变会影响最终的平衡位置和向平衡位置运动的路径。
To study the free rolling movement of a 65? swept sharp leading edge delta wing with aileron deflection, unsteady Euler/Navier-Stokes equations are solved synchronously with the free rolling motion equation of a rigid body. Navier-Stokes simulations are conducted adopting the detached-eddy simulation (DES) based on an Spalart-Allmaras model. In the context of a multiblock structured grid, the arc-length based transfinite interpolation (TFI) method is employed to realize the aileron deflection, while the rolling of the wing is achieved by rotating the whole grid. The analysis of the responses of free-to-roll movement due to the scheduled aileron deflections shows that this delta wing has three different equilibrium positions during rolling which couple well between the two approaches. The wing at the three equilibrium locations are (1) due to symmetric flow, (2) characterized by vortex breakdown on the portside and separated vortex on the starboard side of the wing and dominated by their vortex strength difference, (3) resulting from the rolling moment balance between the contributions from the aileron deflection and leading edge vortices. Additionally, the rolling motion of the delta wing is very sensitive to the amplitude of the aileron deflection angle, which influences the final equilibrium position and the path to it.
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