Vibration and enhanced stability properties of fluid-conveying pipes with two symmetric elbows fitted at downstream end

In this paper, the vibration and stability properties of fluid-conveying pipes with two symmetric elbows fitted at downstream end are investigated. The fluid, after entering from the upstream end, is pushed downwards and eventually exits from the downstream end fitted with two symmetric elbows. The equation of motion is solved by means of Galerkin's method with a four-mode approximation. Calculations are conducted for cantilevered and also for pinned-pinned slender pipes. It is found that the stability of the pipe system can be greatly enhanced with such downstream elbows. The vibration frequency of the fluid-conveying pipes can be comfortably controlled due to the downstream elbows with a selection of angle of inclination. The proposed geometry configuration of fluid-conveying pipes may be useful for the design and improvement of engineering pipeline systems and fluidic devices.