Self-sustained flow oscillations and heat transfer in radial flow through co-rotating parallel disks

An experimental study was conducted to determine the fluid flow and heat transfer characteristics in a passage formed by two parallel rotating disks. The local heat transfer coefficients along the disk radius were measured in detail and the flow patterns between the two rotating disks were visualized by using paraffin mist and a laser-light sheet. It was disclosed that 1) the self-sustained laminar flow separation which is characteristic of the stationary disks still exists even when the disks are set in motion, giving significant influence to the heat transfer. 2) For small source flow Reynolds number, Re, and large rotational Reynolds number, Reω, rotating stall dominates the heat transfer. 3) Heat transfer for steady laminar flow occurs only when both the source-flow and rotational Reynolds numbers are small: Re < 1200 and Reω < 20.