Abstract:In order to get self-servo characteristics and the instantaneous flow situation of internal flow field in rotary hydraulic servo joint, the dynamic numerical simulation was conducted with the dynamic mesh model and UDF offered by Fluent. The instantaneous variations of the pressure, flow rate, and leaves' force of the internal flow field were analyzed. The results show that: this method breaks the limitations of previous CFD steady state simulation, is more realistically simulating the instantaneous variation of internal flow field in the joint, which provides a theoretical basis for the joint' optimized design. Through analysis, the joint has good self-servo characteristics. It can quickly follow the input signal of valve core in the load torque of 100 N·m.