Abstract:
Magnetorheological materials are smart materials where its rheological characteristics can be
quickly changed by the introduction of a magnetic field. The electromagnet and a piston
submerged in an MR fluid make up the MR damper. The MR fluid solidifies as Electromagnet is
subjected to current, and its yield stress changes in reaction the magnetic field that is being
used. Therefore, the magnetic field generation is a significant MR damper phenomenon. In this
work, the magnetic field generated in the damper and dynamic viscosity was analyzed for the
change in coil numbers and MR fluid gap utilizing finite element method using COMSOL
Multiphysics. A 2D axisymmetric, quasi-static model was created utilizing auxiliary sweep study
by changing current from 1.5–4 A and the number of coils 300,400,500 and 600 effects on the
magnetic flux density, yield stress, and dynamic viscosity change caused by externally applied
current in the fluid flow gap of the MR fluid were assessed and for the fluid flow gap of
1mm,1.5mm,2mm with 400 coil turns. The inference obtained after the analysis of results are as
the current is increased the magnetic flux density is also increasing in the MR fluid and as the
magnetic flux intensity increases the yield stress and dynamic viscosity also increases with the
current. When the number of turns in coil increases the magnetic flux density also increases
proportionally and there by yield stress and dynamic viscosity also increases. When the gap
between piston and cylinder increases the magnetic flux density is decreased so there by a
decrease in yield stress and dynamic viscosity is observed.
