电磁力控制翼型绕流分离的增升减阻效率研究

电磁力可有效对流体流动进行控制,增升减阻,抑制流动分离,制约其推广应用的瓶颈为控制效率问题.为提高其控制效率,基于翼型绕流的电磁力控制,对电磁力增升减阻的控制效率问题进行数值研究. 根据能量守恒定律,推导电磁力控制能耗的比,基于升力和阻力计算节省能量. 定义电磁力的控制效率为能量节省与电磁力控制所需能耗的比值,研究不同工况下电磁力增升减阻的控制效率. 发现在控制开始阶段,电磁力能量主要消耗在增加边界层流体的动能上,电磁力控制效率非常低,但电磁力控制效率会随着电磁力工作时间的增长而增加;电磁力控制效率随着来流速度的增加呈指数下降;通过增加电磁力激活板的输入能量可增强电磁力的控制效果,但无法明显增加其控制效率.

RESEARCH OF THE CONTROL EFFICIENCY OF LIFT INCREASE AND DRAG REDUCTION BASE ON FLOW AROUND HYDROFOIL CONTROLLED BY LORENTZ FORCE

Lorentz force can control the flow of low-conduction fluid effectively,increasing lift and reducing drag, suppressing flow separation; however, the problem of control efficiency is the main bottleneck to restrict its application. In order to enhance its control efficiency, numerical simulation research had been carried out base on the flow control around hydrofoil using Lorentz force. Energy consumption of Lorentz force control had deduced on the basis of the law of conservation of energy; the amount of saving energy had calculated by using the lift and drag of hydrofoil. The control efficiency of the Lorentz force is defined as the ratio between saved power and used power. The control efficiency of lift increase and drag reduction under different working conditions had been studied. The results had shown that the control efficiency of Lorentz force index decrease with the increase of inflow velocity, and increase with the control time increase. To increase the input energy of Lorentz force actuator can enhance the control effect of Lorentz force, but cannot increase the control efficiency distinctly.