仿海豚尾鳍襟翼模型气动性能优化数值研究

Numerical Study on Aerodynamic Performance Optimization of Dolphin Fluke-based Split Flap Model

为进一步提高附属襟翼对翼型的升力增效,基于海豚前进时尾鳍的特殊运动形态,提出一种弯曲的翼型尾缘附属襟翼模型。首先,基于以往文献,阐述利用SST k-ω湍流模型进行二维不可压RANS数值模拟方法及翼型绕流数值模拟过程中使用的网格分布方式的正确性;然后,验证分裂式襟翼及仿生弯曲襟翼增升的有效性,并分别对两种襟翼的增升原理进行分析;最后,改变来流雷诺数,研究仿生弯曲襟翼及翼型整体在不同雷诺数下的增升特性及阻力变化原理。结果表明:在普通分裂式襟翼及翼型整体的基础上,提出的仿生弯曲襟翼模型及翼型整体的升力系数最大提高10.96%,升阻比最大提高9.39%;雷诺数的大小与附属仿生弯曲襟翼及翼型整体的升力系数增长率呈正相关,与附属仿生弯曲襟翼及翼型整体的升阻比增长率呈负相关。研究结果可为翼型尾缘附近附属襟翼的增升设计提供参考。

To further improve the lift efficiency of the attached flap on the airfoil, this paper proposed a curved airfoil trailing edge attached flap model based on the special motion form of the fluke when the dolphin moves forward. Firstly, based on the published literature, the correctness of the SST k-ω Turbulence model used in the numerical simulation of two-dimensional incompressible RANS and the grid distribution used in the numerical simulation of airfoil flow were described. Then, the effectiveness of split flap and bionic curved flap was verified, and these lift principles of the two kinds of flaps were analyzed respectively. Finally, the lift characteristics and drag variation principle of the bionic curved flap and airfoil under different Reynolds numbers were studied by changing the incoming flow Reynolds number. The results show that: on the basis of ordinary split flap and airfoil as a whole, the lift coefficient of the proposed bionic curved flap model and airfoil as a whole increases by 10.96%, and the lift-to-drag ratio increases by 9.39%;the Reynolds number has a positive correlation with the lift coefficient growth rate of the attached bionic curved flap and airfoil as a whole, and a negative correlation with the lift-to-drag ratio growth rate of the attached curved split flap and airfoil as a whole. The results of this paper can provide a reference for the design of lift augmentation of the attached flap near the trailing edge of the airfoil.