Library Subscription: Guest
Proceedings of the 27th National and 5th International ISHMT-ASTFE Heat and Mass Transfer Conference December 14-17, 2023, IIT Patna, Patna-801106, Bihar, India
December, 14-17, 2023, Bihar, India

Heat transfer and flow characteristics in square and filleted square channels rotating about a parallel axis

Get access (open in a dialog) DOI: 10.1615/IHMTC-2023.1000
pages 619-624

Abstract

Cooling of electrical devices such as motors and generators are crucial for their efficient performance. A commonly used method to cool the rotor of these machines is by passing a coolant (air, hydrogen etc.) through channels inscribed in the rotor. These channels are therefore rotating about a parallel axis and the coolant experience rotation induced Coriolis and centrifugal forces. In this study, numerical analysis of square and filleted square channels (FSC) rotating about a parallel axis with air as coolant was conducted to understand the influence of Coriolis and centrifugal forces on the thermal and flow characteristics. Rotation number was varied as 0, 0.15 and 0.4 at a constant heat flux condition of 11,000 W/m2. It was observed that the magnitude of Coriolis force is high towards the entrance zone which increases the heat transfer for both square and FSC channels. As the flow develops, centrifugal buoyancy becomes more dominant and forms counter rotating pair of secondary vortices. For square domain, the heat transfer suddenly decreases at the corners. This corner effect is negligible for filleted square channel and therefore shows 15%, 27% and 32% higher Nusselt number than square channels for Ro = 0.4, 0.15 and 0 respectively