A Basic Research On MR Fluid Starter

MRF (Magneticrheologic Fluid) is a smart material with wide prospect. It perform a nature of Newton fluid without magnetic field; subjected to magnetic field, it perform a nature of viscoelasticity (could be expressed by Bingham Model). With this character, it could be employed in a motor soft starter.The output of a starter is output torque. In order to calculate the torque, the relationship between main parameter of MRF-yield stress Ï„y and intensity of magnetic field MRP subjected to have to be carried out first. It had been proved that Ï„y(H) =aMs2 +bH2 +cMsH, where a, b and c are parameter related to MRF material itself. The relationship is a unique one to a specified MRF. That is to say, the function of yield stress Ï„y vs. intensity of magnetic field could be obtained on the experimental data.This article based on the solution of the function of Ï„y vs. intensity of magnetic field and carried out a conceptual model of a soft starter, the model is analysed by the FEA software of ANSYS for distribution of intensity of magnetic field. Some other models with different material, different structure and different excitation are also analysed comparatively to optimize the model. The function of intensity distribution is established on the base of analysis.The mathematical model of torque of the starter can be concluded on the base of the function of Ï„y-H and the function of intensity distribution now. the mathematical model is established by the Bingham Model. The output torque of starter is calculated on the mathematical model and dimension of the conceptual model.