翼型绕流电磁控制的实验和数值研究

Experimental and numerical investigations on the electro-magneticcontrol of hydrofoil wake

分布在弱电介质溶液中的电磁力(Lorentz力),可以有效地控制边界层的流动.利用以转动水槽为主的实验系统和基于双时间步Roe格式的数值方法,对翼型绕流的电磁控制进行了实验和数值研究.结果表明,对于一定攻角的翼型,电磁力可以控制其绕流形态.当电磁力方向与流动方向相同时,可以抑制分离,消除涡街,其效果与减小攻角类似.当电磁力的方向与流动方向相反时,可在流场中形成大涡组成的涡街,增强流体的混合能力,其效果与增大攻角类似.

The Lorentz force generated in the low-conduction fluid can be used to control the boundary layer effectively. In the present paper, experimental and numerical investigations have been performed to suppress the flow separation of a hydrofoil with a certain attack angle in the low-conduction fluid. Both experimental and numerical results show that the l^rentz force parallel to the moving fluid can suppress the flow separation and thus remove the yon Karman street. However, when l^rentz forces are applied opposite to the moving fluid of the surface of the foil, the separation point cannot be suppressed, instead, it would move reversely to the leading edge and the vortex street of the downstream acts as in the cases with a large attack angle.