Elbow angle effect on hydraulic pipeline vibration characteristics

Aircraft hydraulic pipeline vibration affects aircraft conduit system service life and flight safety. The vibration is mainly composed of pump vibration, fuselage vibration, and pipeline and fluid coupling vibration. The first two can be reduced efficiently through soft connection, however, the latter needs an optimization design to avoid coupling vibration. The bending zone is a sensitive area in the coupling vibration. Here, a certain type of aircraft pipeline subjected to a high periodic pressure was analyzed with the finite element method and CFD, the elbow angle effect on the pipeline vibration characteristics under an unsteady flow was studied. The results dedicated that the amplitude and the peak-peak vibration values drop 50% and 68.29%, respectively when the elbow angle changes from 90° to 60°, so the elbow angle effect should be given more attention in future designs.