Numerical and experimental studies on transport phenomena in rotating channels with throughflow.

Abstract

The present study consists of two related investigations: (1) a numerical study on fluid flow, heat transfer and flow instability phenomena in rectangular straight channels that rotate around an axis perpendicular to the channel longitudinal axis, and (2) an experimental study on heat transfer in a rotating serpentine passage with/without roughness on passage walls under uniform wall heat flux. The numerical study was computed by the finite volume and finite difference methods under different thermal boundary conditions, i.e., uniform wall temperature and uniform wall heat flux. The effects of geometric and physical parameters on the friction factor, Nusselt number, flow temperature and velocity distributions, and flow instability phenomena have been investigated and compared with the existing literature. In experiments, the effects of the flow rate, rotation speed, ribs and angle-of-attack of ribs on heat transfer of serpentine passage have been determined. It is revealed that the interactions among the inertia, viscous and Coriolis forces play crucial roles in transport phenomena. It is also revealed that the Reynolds number, Rossby number, channel aspect ratio, thermal boundary condition, and distance from the entrance determine the fluid flow and heat transfer characters. In the experimental investigation, roughness and the angle-of-attack of ribs have proved to have significant influences on the heat transfer performance.