Mathematical Modelling and Dynamic Analysis of a Direct‐Acting Relief Valve Based on Fluid‐Structure Coupling Analysis

Abstract

To explain the sudden jump of pressure as the variation of water depth for a direct-acting relief valve used by torpedo pump as the variation of water depth, a 2-DOF fluid-structure coupling dynamic model is developed. A nonlinear differential pressure model at valve port is applied to model the axial vibration of fluid, and a nonlinear wake oscillator model is used to excite the valve element in the vertical direction; meanwhile, the contact nonlinearity between the valve element and valve seat is also taken into consideration. Based on the developed dynamical model, the water depths for the sudden jumps of pressure can be located precisely when compared with the experimental signals, and the corresponding vibration conditions of the valve element in both the axial and vertical directions are explored. Subsequently, in order to eliminate the sudden jumps of pressure, different pump inlet pressure was tested experimentally; when it was decreased to 0.4 MPa, the pressure jumps ever appeared during the dropping and lifting processes were removed, and the numerical simulation based on the developed mathematical model also verified the experimental measurements.

Study on the Influencing Factors of the Response Characteristics of the Slide Valve-Type Direct-Acting Relief Valve with External Orifice

“…Zahariea [8] developed a functional diagram to perform numerical analysis of an electromagnetic normally closed direct-acting ball valve with cylindrical seat using the MATLAB/Simscape/SimHydraulics programming language. Wen et al [9] developed a 2-DOF fluid-structure coupling dynamic model to explain the sudden jump of pressure as the variation of water depth for a direct-acting relief valve used by a torpedo pump as the variation of water depth. Erdodi and Hos [10] proposed two CFD-based methods for the analysis of the fluid forces and valve stability, including steady-state CFD method and dynamic CFD simulations.…”