Abstract: In order to investigate the multi physics coupling characteristics in the recoil process of magnetorheological (MR) damper, an independent three-stage MR damper of double rod was designed. Magnetorheological gel (MRG) based on silicone was prepared and the steady-state shear test was carried out for obtaining the consistency coefficient and the non-Newtonian index of the Herschel-Bulkley model. MRG-70 was applied to the damper, and the motion analysis of recoil part was carried out by combining with the law of chancing of the bore resultant force for a certain type fixed artillery. The multiple physical fields of damper was analysed and calculated. The results show that Poiseuille pressure flow loss and Couette viscous flow loss are the main and controllable parts of the damper. The temperature of each pole corresponds to a different peak value at different times, and the temperature distribution was obviously nonlinear and time-variable. The pressure distribution and the pressure drop on the central axial surface of the damping channel are nonlinear and time-variable, the dynamic viscosity of the central axial surface of the effective damping channel is also obviously nonlinear and time-variable, and varies sharply at each pole, and the peak value fluctuates with the position.

Key words: magnetorheological gel, Herschel-Bulkley model, nonlinearity, time variability, Poiseuille pressure flow, Couette viscous flow