Abstract: Fluid-solid coupling numerical simulation technique is adopted to research the dynamic characteristics of safety valve / gas tank system charging and discharging. The fluid control equation used in the computation is three-dimensional Euler equation, and finite volume scheme of unstructured grid is adopted for solution. The motion equation of solid structure is derived from Lagrange equation, and Newmark method is adopted for solution. The technique of zero-thickness virtual baffle with variable strake is proposed to simulate the transient process of the main valve from closing to opening. The dynamic response characteristic of elastic element in the process of opening and closing of valve are obtained through computation. The results show that the main diaphragm produces high frequency oscillation at both places of upper and lower limits of travel. The main diaphragm is subjected to the action of impact load at the instant of opening and closing of valve, and oscillation of load occurs at the instant of closing of valve. This oscillation impact could be the cause of valve screaming and diaphragm damage.

Key words: Euler equation, Fluid and structure interaction, Unsteady flow, Unstructured grid, Valve