将条状电极和磁极交错布置的电磁场激活板置于弱电解质溶液中,在流体边界层上产生具有明显分布特征的电磁力(Lorentz力),利用电磁力可以改变流体边界层的结构,控制边界层的流动脱落与分离,可以增加翼型升力,减少其阻力,实现对翼型失速的控制。利用电磁力控制流体边界层的方法属流体主动控制方法之一。本文首先基于电磁场和流体的基本方程,对置于弱电解质中的不同极板宽度的电磁激活板周围的电磁场及产生的Lorentz力进行了数值模拟;其次,通过实验来验证此方法的有效性。将包覆有电磁激活板的翼型置于弱电解质溶液中,利用基于TMS320F2812(DSP芯片)组建的翼型失速实验控制系统来灵活改变翼型的迎角和转速,测量升力和阻力的变化;实验结果表明,正向电磁力能够有效地抑制和延缓翼型失速现象的发生。
By means of electromagnetic forces(Lorentz force),the structure of the flow boundary layer may be modified,which is one of the active methods for flow controlling.With the forces generated by electromagnetic fields and localized around the electrolyte liquid boundary layers,the structure of the flow boundary layer may be modified and the flow separation from the surface may be controlled effectively.The electromagnetic force provides with the effective affects of increasing the lift forces of the hydrofoil and reducing drag and controlling the hydrofoil stall.This paper is concerned about the basic theory of weakly conducting fluid boundary layer control by electromagnetic body forces,and the hydrofoil covered with electromagnetic actuators was put into electrolyte liquid.The experimental control system based on DSP chip TMS320F2812 was used to change expediently the angle of attack and speed,and measure the lift and drag of the hydrofoil.The experimental results show that positive electromagnetic force can restrain and stave off hydrofoil stall availably.