调谐式磁性液体减振器固有晃动频率分析与实验研究

Analysis and experimental research on intrinsic sloshing frequency of tuned magnetic liquid damper

根据磁性液体的超顺磁特性,提出了一种调谐式磁性液体减振器。该减振器由非磁性液缸、电磁线圈和磁性液体构成,通过电磁线圈施加外部磁场,改变非磁性液缸内磁性液体的固有晃动频率,使其能在较宽的频率范围内达到最佳减振效果。根据磁性液体的伯努利方程和连续性方程得到磁性液体固有晃动频率的表达式。实验验证了该减振器在不施加外部磁场时相当于传统调谐液体阻尼器,当外部振动频率变化时,可以改变外加磁场使得减振器的减振效果不会随着外部振动频率的变化而降低。同时还发现,外加磁场不仅能通过改变频率来增强减振效果,较大的磁场也会使得减振效果略有提升。

A tuned magnetic liquid damper is proposed according to the superparamagnetic property of the magnetic fluid.This damper is composed of a non-magnetic fluid cylinder,an electromagnetic coil and a magnetic fluid.By using the external magnetic field through the electromagnetic coil,the intrinsic sloshing frequency of the magnetic fluid in the non-magnetic fluid cylinder can be changed to achieve the best vibration reduction effect in a wide frequency range.The experiment shows that the damper is equivalent to the traditional tuned liquid damper without the external magnetic field.When the external vibration frequency changes,the external magnetic field can be changed so that the damping effect of the damper does not decrease with the change of external vibration frequency.It is also found that the external magnetic field can not only enhance the damping effect by changing the frequency,but also make the damping effect slightly improved by the larger magnetic field.