Radially resolved measurement of stator heat transfer in a rotor–stator disc system

This paper describes a new experimental method for measuring stator heat transfer in a rotor–stator disc system using an electrical heater array. The system is partially blocked at the periphery, with radial outflow of rotor-pumped air from an inlet at stator centre. The aim is to improve thermal performance prediction for air-cooled disc type electrical machines. Local Nusselt numbers were measured for 0.63e5Reθ>3e5 for all gap ratios. Increased Nusselt numbers at the periphery are observed for all ReθReθ and G because of the ingress of ambient air along the stator due to the rotor pumping effect.