Abstract: Hydraulic damper is an important component of the travel unit of train, its damping characteristics are fulfilled by a group of damper valves of special structure. In order to optimize the whole runner structure of hydraulic damper cylinder and analyze the influence of local flow field on the damping characteristics when the key damper valve is in different open positions, it is necessary to use fluid dynamic 3D simulation calculation method to estimate its characteristics. Aiming at the structure and parameters of vertical damper used on a train of typical structure, a corresponding mathematical model and physical model are built. Alternating flow fields in valve body and in inner and outer cylinders under various typical vibration conditions are simulated by using CFX adaptive dynamic grid technology, then velocity fields, pressure fields and streamline distributions of corresponding runners are obtained. By further using visualized analysis method based on 3D flow field, the fluid flow condition of every key runner is reflected clearly and roundly. The obtained working curve of damper agrees with the practical standard characteristic curve, thus proving the feasibility of the analytical models and the effectiveness of the simulation method, which provides theory basis for analyzing the damper energy dissipation process from the mechanism, and also provides a quick and effective way for structure optimization design of runner.

Key words: Damper valve, Dynamic simulation, Hydraulic damper