Research on analyzing method of pulsation transfer characteristics of hydraulic circuit components based on CFD

Abstract

In recent years, the computational numerical analysis makes it possible to find out various kind of unknown phenomenon in the fluid power systems due to rapid improvements of computer. The three dimensional transient CFD (Computational Fluid Dynamics) analysis can be a powerful tool for understanding the transient flow phenomenon inside pumps, valves and other hydraulic components. It can be also used for analyzing the pulsation phenomenon such as pressure and flow ripple in the hydraulic circuits. The aim of this report is to study on the analyzing method of the pulsation transfer characteristics of hydraulic circuit components by the CFD approach. A rigid pipe for the hydraulic line and a quarter wavelength side branch silencer are chosen as the analyzed hydraulic components. The transient CFD analysis is conducted to obtain the time history pressure and flow ripple at inlet and outlet of component. These time domain data are converted into the frequency domain by FFT, and the pulsation transfer characteristics which is represented by the four pole transfer matrix can be obtained as the frequency dependent characteristics. The results are compared with the theoretical and experimental results to verify the accuracy. The investigations about the CFD settings are also carried out to acquire the knowledge of calculation settings for pulsation phenomenon in the fluid power system.