ORBITAL FLOW PAST A CYLINDER: EXPERIMENTAL WORK.

The work presented in this paper is partly an extension of an experimental investigation undertaken by Holmes and Chaplin who used a rotating arm rig in which a vertical cylinder was driven around in a circular orbit while also rotating on its own axis in otherwise still water. This is similar to the flow past a horizontal cylinder under regular deep water small amplitude waves where the particle orbits are almost circular. Force and pressure measurements over a Reynolds number range of 0. 2 multiplied by 10**5 less than Re less than 2. 4 multiplied by 10**5 and a Keulegan-Carpenter number range of 12. 8 less than Kc less than 53. 5 for smooth and rough cylinders are presented.