Dynamics of a radial electrorheological clutch

Time dependent solutions to the equations of motion for flow in an enclosed radial electro-rheological clutch are developed and discussed in relation to the speed of operation. The method follows a procedure previously develo ped for cylindrical clutch geometry but in this case analytical solutions a re obtained. The fluid is treated as a homogeneous continuum obeying the Bi ngham plastic constitutive equation incorporating a yield stress and viscou s component. The results show that the acceleration expected from a conside ration of yield stress and inertia is not always achieved. The viscous comp onent places fluid dynamic restriction on the maximum acceleration of the o utput rotor. However, this limit is only approached if the output load iner tia is very low. The results have a bearing on the choice of fluid for high speed operation.