Analyzing Dynamic Characteristics of Side-branch Resonant Hydraulic Pulsation Dampers

We computed the transient state of a side-branch resonant hydraulic pulsation damper with CFD (com-putational fluid dynamics) codes to analyze the relationship between its dynamic characteristics and cavity struc-ture.Under the laminar condition, we used the M-sequence pressure signal to simulate the pressure wave that acts as boundary in order to simulate the transient state of the pulsation damper with fluid compressibility.We trans-formed its transient pressure sequences into its frequency characteristics through the fast Fourier transform.We compared the frequency responses of the pulsation damper and insert loss among pulsation dampers with the same cavity volume but different diameters and lengths.We simulated the pressure impact with the step pressure and showed the flow field.We designed pulsation dampers with different cavity volume, and compared their perform-ance.We analyzed the relationship between the base frequency of the pulsation damper and the diameter-to-length ratio by using the distributive parameter model.The analysis results show that: 1) the pulsation damper's dynamic characteristics have relations with its cavity's diameter-to-length ratio and decrease when the ratio is less than 1 and decreasing; 2) the pulsation damper's base frequency is smaller and increases little when the ratio is larger than 1 and increasing.Therefore designers should decrease the volume of the pulsation damper that has a smaller cavity and lower diameter-to-length ratio so as to keep its resonance frequency stable.