电磁力控制翼型三维绕流场特性的数值研究

摘要

This paper numerically researches the flow structures around a hydrofoil and the lift/drag char-acteristics influenced by the electromagnetic force in a weakly conductive fluid at a chord length Reynolds number 2.9×106 with the method of detached eddy simulation (DES). The effects of the electromagnetic force on the three-dimensional flow characteristics and stall problem of a hydrofoil are investigated at a stall attack angleα=20°. The results show that the electromagnetic force can improve the flow structures around a hydrofoil and significantly reduce the three-dimensional flow characteristics. The electromagnetic force increases the kinetic energy near the boundary layer of the hydrofoil surface, delay the flow separation and change the vorticity field characteristics. Meanwhile, the electromagnetic force can decrease the drag force and the fluctuation amplitudes of the lift, increase the lift, reduce the drag, and raise the lift-drag ratio. Moreover, the electromagnetic force can significantly delay the stall problem and increase the stall angle, improve the working performance.%在弦长雷诺数ReL=2.97×106下，采用脱体涡模拟方法对弱电解质中电磁力作用下翼型绕流场特性进行了数值模拟，研究了电磁力作用控制翼型失速攻角时绕流场中三维流动特性及失速问题的规律和机理。结果表明：电磁力作用可有效改善翼型周围的流场结构，显著减小翼型绕流场三维特性，并使翼型表面流体动能增加，当电磁力作用足够大时，其表面涡量转变为正向涡量。同时，电磁力作用可增加翼型升力，减小阻力，显著减小升阻力脉动特性，提高翼型升阻比，还可以显著延缓翼型失速特性，增加失速攻角，提高工作性能。