Heat transfer to a fluid in radial, outward flow between two coaxial stationary or corotating disks

An experimental study of heat transfer rates to air flowing radially outward between two coaxial, corotating disks was made. Heat transfer data were obtained for five mass flow rates with stationary disks and four mass flow rates and five rotational speeds with rotating disks. Rotation of the disks slightly decreased the average Nusselt numbers compared with the average Nusselt numbers without rotation at the highest speed of rotation (600 rmp), but at lower speeds no consistent trends were observed. The average Nusselt numbers, with and without rotation, can be related as Nu(bar) = 0.0529 Re to the 0.71 and the local Nusselt number as Nu = 0.124 Re to the 0.608.