电磁消涡与减震技术研究

Vortex-Suppression and Vibration-Absorption by Means of the Electromagnetic Body Forces

利用流体边界层上的电磁体积力控制流体边界层的周期性脱落与分离,限制尾流涡街的产生,从而实 现消除涡流和减少涡生震动的目的．理论分析和实验研究表明,当圆柱表面包覆的电磁场作用参数N>1,包覆 磁场强度B≥0．5 T,流体边界层表面电流密度j为103 A/m2数量级时,对于一般情况下的流场参数而言,流体边 界层上的电磁体积力具有十分良好的消涡与减震控制作用效果．优化圆柱体表面的电磁场包覆范围,可以提高 电磁消涡减震控制效率．当流体边界层上的电磁体积力方向与流体边界层的流动方向相反时,电磁力又具有显 著的增涡增震控制作用效果．

Introducing electromagnetic body forces localized around at the flow boundary layers for controlling the flow boundary layer separation and shell off from the blunt body surface periodically, for restricting the wake street, for suppressing the vortex stream and absorption of the vortex induced vibration, have been conducted. It have been indicated by theoretical analysis and experimental study that the controlling effects of the electromagnetic body forces have been remarkable as the action parameter of the electromagnetic field (N) equaling to 1, the magnetic flux density (B) approaching to 0.5T, and the electric current density (j) near around the flow boundary layer up to 103 A/m2 scalar for general flow conditions. By optimizing the area of the electromagnetic fields flush mounted around the surface of the cylinder, the controlling effects of electromagnetic vortex suppression and vortex induced vibration absorption may have been improved. While the electromagnetic force directed opposed to the mean flow of the flow boundary layer, the obvious vortex acceleration and vibration amplify may have been presented.