基于周期性条件的临近空间螺旋桨气动仿真

The Numerical Study of Propeller Aerodynamics Characteristic in Near Space Based on Periodicity Conditions

基于滑移网格模型,通过求解三维非定常N-S方程,采用周期性边界条件对临近空间螺旋桨的气动性能进行了三维数值研究,所得结论与理论分析和文献所示结果一致。研究表明,运用周期性边界条件可以大大节约计算资源和时间,在计算机性能有限的情况下,是一种研究螺旋桨气动性能的方法。在所研究的工况内,随转速的增加,临近空间螺旋桨拉力和扭矩不断增加,叶素的速度峰值点不断前移;随着进距比的增大,螺旋桨效率先增大后突降为负值,然后又突升为大于1的值;临近空间的低雷诺数条件使得螺旋桨效率下降。

The propeller aerodynamics characteristic was numerical study based on sliding meshes, periodic boundary conditions and 3D unsteady N-S equations in near space, and the reasonable numerical results are consistent with the reference and theoretical analysis. The results show that, the computer resources and computing time can be saved using the periodic boundary conditions. A numerical method has been found to investigate the propeller aerodynamics characteristic when the computational is not good enough. The pull and torque of the propeller will increase as the rotational speed increases in all conditions of this paper. The max velocity point will move closer to the front of the airfoil as the rotational speed increases. As the advance coefficient increases, the efficiency will increase and then decrease down to negative value sharply, finally back to a value bigger than 1. The low Reynolds condition in near space will reduce the efficiency of the propeller.