Hydrodynamic Performance Analysis of an MR Damper in Valve Mode Characterized by the Mason Number

This work analyzes the hydrodynamic behavior of a magnetorheological valve, considering the microscopic fluid characteristics to generate a damper force. The magnetorheological fluid is composed of ferromagnetic particles dispersed in a non-magnetic carrier fluid, whose mechanical resistance depends on the magnetic field intensity. In the absence of a magnetic field, the magnetorheological fluid behaves as a liquid whose viscosity depends on the particle volume fraction. Conversely, the presence of a magnetic field generates particle chain-like structures that inhibit fluid motion, thereby regulating flow in the control valve. The mathematical model employs the continuity and momentum equations, the Bingham model, and the boundary conditions at the solid–liquid interfaces to determine the flow field. The results show the fluid hydrodynamic response under different flow conditions depending on dimensionless parameters such as the pressure gradient, the field-independent viscosity, the yield stress, the particle volume fraction, the Bingham number, the Mason number, and the critical Mason number. For a pressure gradient of Γ=−10, the flow rate inside the valve (with particle volume fraction ϕ=0.2) results in Q¯T,x=0.34, 0.06, and 0 when the magnetic field is 80, 120, and 160 kA m−1, respectively. Likewise, when the magnetic field increases from 80 to 160 kA m−1, the damping capacity increases by 88% when ϕ=0.2 and 128% when ϕ=0.3 compared to the Newtonian viscous damping. This work contributes to our understanding of semi-active damping devices for flow control.