Effect of Inlet Swirl on the Turbulent Flow in an Axially Rotating Pipe

The effect of the inlet swirl on the flow in a pipe rotating about its axis was investigated experimentally, when a honeycomb was mounted on the inlet portion of a rotating pipe. The tangential component of velocities exhibited a forced vortex type profile and the axial velocity component was approximately in a fully developed turbulent flow. As the flow proceeded down-stream, the tangential velocity profile, having a straight velocity gradient, was seen to be deformed into a concave type. In this process, the swirling component of velocities near the pipe wall was seen to grow up over the peripheral speed of the pipe wall, which was confirmed by flow visualization. The measurements of the Reynolds stress components showed that the solid body rotation weakened the stabilizing effect which was expected from the rotational flow motion.