临近空间介质阻挡放电特性及其提高螺旋桨性能的数值分析

Numerical Study on the Characteristics of the Dielectric Barrier Discharge and Plasma to Enhance Propeller Characteristics in Near Space

为研究介质阻挡放电(DBD)等离子体对临近空间螺旋桨气动性能的提高效果,首先基于静电场方程和漂移-扩散方程,研究了临近空间DBD特性,得到等离子体时均体积力分布,通过求解N-S方程,结合叶素理论,分析了等离子体对叶素流动分离的抑制作用和螺旋桨整体气动性能的影响。主要结论有:在临近空间中,DBD电极附近最大离子数比大于最大电子数密度,但离子分布范围小于电子。时均体积力的最大值约为9 000 Nm3。不同工况下,等离子体对桨叶上叶素的有效作用区域和作用效果是不一样的;当螺旋桨转速分别为600 rmin、1 500 rmin和3 000 rmin时,螺旋桨总拉力分别提高29.63%,9.91%和6.11%,总效率分别提高14.3%,2.6%,1.2%。

This paper is aiming to study the effect of dielectric barrier discharge(DBD) plasma to enhance aerodynamic characteristics of near space screwpropeller. First the characteristics of dielectric barrier discharge processes were numerical studied based on the Poisson's equation for electric field and drift-diffusion equations for density of ion and electron,and the time average body force of dielectric barrier discharge plasma was obtained. Then the effects of DBD plasma flowseparation control on propeller blade element and the effects of DBD plasma to enhance aerodynamic characteristics of the whole propeller were numerical analyzed. The results showthat the max ion number density is big than the max electron number density,but the distribution region of ion number density is less than electron number density. The max time average body force is about 9 000 N /m3. The region of blade element on propeller blade and the effect of plasma flowcontrol is not completely uniform in different conditions. When the rotate speed is 600 r/min,1 500 r/min and 3 000 r/min in the caseof this paper,the increment of the whole thrust is 29. 63%,9. 91% and 6. 11%,and increment of whole efficiency is 14. 3%,2. 6% and 1. 2%.