Experimental Study On Pressure Pulsation and Acceleration Response of Fluid Conveying Pipeline Under Multi-Excitation

The fluid conveying pipelines are often subjected to internal fluid fluctuation excitation in hydraulic pump and external base excitation from aeroengine rotor. To investigate the acceleration response of pipeline and pressure pulsation response of fluid, the vibration tests of pipeline under base excitation, fluid fluctuation excitation and multi-excitation are conducted. A set of test bench and test scheme of pipeline system under multi-excitation are designed. The test data are collected by piezoelectric pressure sensor and three-direction acceleration sensor. By analyzing the test data, the following results can be obtained: Under base excitation, the internal fluid still has weak pressure pulsation response even without fluid fluctuation excitation. However, the pressure pulsation response remains unchanged with the increase of base excitation amplitude. Under fluid fluctuation excitation, the amplitudes of vibration responses at fluid fundamental frequency fp increase with the increase of pump pressure except at 9 MPa and 15 MPa. The natural frequency of pipeline is close to 3fp when the pump pressure is 9 MPa and 15 MPa respectively, and the pipeline system will have resonance. Under multi-excitation, the amplitudes of vibration responses are close to the superimposed amplitudes of two single source excitations at fb=175 Hz and fp=298 Hz. The vibration responses appear beat vibration at fb=298 Hz and fp=297.6 Hz. The relevant test scheme and test data analysis adopted in this paper have important reference value for the in-depth study of pipeline vibration under multi-excitation and engineering practice.