Forces on Vibrating Cylinder Near Wall in Current and Waves

Abstract

Forces on a vibrating pipeline have been measured by measuring the instantaneous pressure in eight pressure cells around a vibrating cylinder. The cylinder can only vibrate in the cross‐flow direction. The vibrations are forced. The waves are introduced by the carriage technique. For the current‐alone case it turns out that the drag and the lift increase significantly with increasing amplitude of vibration. The influence is most pronounced at small values of the reduced velocity, where the increase can be up to a factor 3–4 for a free cylinder. Closer to the wall the influence is smaller for the drag, but very large for the lift. In the wave case, the drag, the inertia force, and the lift increase when the pipe is vibrating; the increase in drag is most pronounced for small