【摘要】 基于广义无限插值理论生成了适用于模拟微型扑翼粘性绕流的三维C-O型网格,应用有限体积法结合双时间推进技术求解了微型扑翼在低速、低雷诺数下的粘性绕流。控制方程采用预处理后的三维可压缩非定常N-S方程组,有效地克服了低速流动条件下求解常规可压缩N-S方程遇到的刚性问题。通过与参考文献结果的比较验证了文中方法的正确性,并研究了扑翼相关参数对其气动特性的影响。文中所得到结论对扑翼的气动设计具有指导意义。更多还原

【Abstract】 A three-dimensional(3-D) moving grid adapting to simulation of viscous flow over flapping wing based on the transfinite interpolation is developed,and the 3-D compressible unsteady Navier-Stokes equations transformed by preconditioning method are employed by finite volume method and dual-time stepping method.As the computational results are in good agreement with reference data,the method given in this paper is correct and reliable.The flow over a flapping wing in the motion of plunging combined with pitching is complicated due to the change of some key parameters such as reduced frequency,flapping amplitudes and attack angle.Through careful computations,the influence of reduced frequency,flapping amplitudes and attack angle on lift,thrust and lift/drag ratio is determined.Reduced frequency is a quadratic function relation of thrust;as reduced frequency increases,the lift will rise rapidly.Flapping amplitude mainly influences the peak value of lift coefficient;as flapping amplitude increases,the peak value of lift coefficient will increase speedily,but the average of lift will decrease.Attack angle mainly influences the average of lift and lift/drag ratio;as attack angle increases,lift/drag ratio will decrease rapidly,but the average of lift will increase.更多还原