Numerical Investigation of Flow Characteristics in a Viscous Damping System with Symmetrical Hydraulic Cylinders

Abstract

Hydraulic dampers are widely applied due to their characteristics of absorbing huge impact energy, stable and reliable working performance, and easy on-demand design. The hydraulic cylinder is an important part of the hydraulic damping system and the flow conditions inside the cylinder significantly affect its performance. However, only a few researches related to the flow field inside the hydraulic cylinder have been reported. In this study, a novel viscous damping system with opposing symmetrical hydraulic cylinders that can guarantee the smoothness of vibration absorption in a single degree of freedom is proposed. The advantage of this design is that the damping characteristic can be regulated using the external flow valve provided in the external hydraulic loop. The hydraulic damping system is simulated using the commercial software ANSYS Fluent software environment, different strokes and frequencies are applied to observe the internal flow characteristics. As can be seen from the results of numerical investigation, when the piston on one side moves, the piston on the other side also moves, and the pressure change in the cylinder is caused by the collective effect of the cavity volume change and the flow change of the hydraulic oil. In addition, by comparing the streamline and velocity distribution in the cavity under different strokes and frequencies, the relationship between vortex and velocity and compression distance is summarized. These results provide valuable information to facilitate the design of viscous damping system with symmetrical hydraulic cylinders.