Analysis of Flow around a Flying Pipe

The present aim is to reveal the flow past a rotating pipe which is immersed parallel to the mainstream. At first, we conduct field observations of a flying pipe using a pair of high-speed video cameras, together with motion analyses based on their recorded images, which quantitatively reveal both paths and angular velocities of the flying pipe. In addition, we conduct numerical simulations by a finite difference method, whose results suggest that the pipe-rotation effect becomes remarkable for a rotation parameter Ω*> 0.4.