Optimal design of control valves in magnetorheological fluid dampers using a nondimensional analytical method

The magnetorheological control valve is a key element in magnetorheological dampers to achieve controllable damping characteristics in practice. The optimal design of magnetorheological control valves with an annular flow structure in two configurations of coil wire placements is investigated using a nondimensional analytical method. The achievable performances of the magnetorheological control valve are formulated in terms of several important nondimensional design parameters, which are defined based on the analytical models considering both mechanical flow characteristics and magnetic flux conservation in magnetorheological fluids and valve materials with a clear understanding and convenient specification in optimization. The design method first identifies a few optimal internal parameters through maximizing a single-objective function with predefined constraints. This can avoid empirical difficulty or uncertainty in weight selection in conventional multiobjective optimization methods and guarantee the worst-case performance. Then, the inherent sensitivity of the achievable performance with respect to external parameters is analyzed to provide practical instructions for appropriate design of the magnetorheological control valve. Finally, the analytical optimal results are verified by a finite element analysis, and a comparison is conducted to illustrate the excellent performance of a vibration isolation system employing the optimally designed magnetorheological control valve.