Performing CFD analysis of non-Newtonian MR fluid flow with generalized upwind and TVD schemes

Magnetorheological (MR) dampers can absorb different forces at different speeds by offering the advantage of an adjustable damping coefficient instantly. This characteristic feature is made possible by the specially designed piston of the MR damper. The piston force can be adjusted depending on the magnitude of the magnetic field strength by passing an MR fluid affected by the magnetic field through a flow section in the piston exposed to the magnetic field. In this study, the Computational Fluid Mechanics (CFD) analysis of an MR fluid with non-Newtonian characteristics between parallel plates has been performed. The momentum equations discretized within the scope of CFD were made according to six different flow schemes and the numerical solution was carried out with a set of codes written in the MATLAB program. By presenting all the steps of these discretization in the most understandable way, It is aimed to develop an applicable numerical solver for two-dimensional flow fields that can be solved with a structured mesh for non-Newtonian MR fluid flow. In this study, the analysis of the flow occurring in the circular annuli was made by reducing the problem into parallel plates, and velocity and pressure fields along the flow field were obtained. Both steady and unsteady CFD analyzes were performed. In the first of the steady fluid flow case, velocity and pressure fields were obtained for different Reynolds numbers, according to six different discretization schemes in creeping flow conditions. In another steady case, the effect of coil length (or effective zone thickness) on velocity and pressure fields along the channel was investigated. For the unsteady fluid flow analysis conditions, the force-time, force-displacement and force-velocity graphs under constant magnetic field excitation are obtained by using a sinusoidal piston velocity for a relatively small-scale MR damper. Keywords: Magnetorheological fluid, MR damper, Numerical analysis, Discretization, Parallel plates, non-Newtonian fluid, Herschel-Bulkley fluid