Shallow Water Flow on a Rotating Circular Cylinder : the Case of a Rotating Cylinder

Abstract

Observation of the flow pattern and the measurement of water depth of the shallow water flow on a rotating circular cylinder were carried out. The results of the investigation showed that the roll wave which existed on a still cylinder did not exist on a rotating cylinder, and that the stationary centrifugal force wave (SC wave), the long-wave length wave (LW wave) and the ripple which started immediately downstream from the nozzle exit were generated when the flow velocity increased. The rotation of the cylinder strengthened the intensity of the waves which moved in the circumferential direction, and the SC and LW waves formed the cell structure in the downstream when a certain condition was satisfied. As a result, the extent of the regions of each flow pattern was obtained.