Analysis of Self-Cooling Method of a Rotor using Buoyancy Driven Convection

Lately, hybrid aircraft has gained a lot of attention because of its efficiency. This type of aircraft relies on a mix of gas turbines engines and the electric propulsion system. The gas turbine engine can be used to charge the battery and provide auxiliary power to the electric system or may operate continuously and use the electric system to decrease fuel consumption. The main challenge in the design of hybrid aircraft is to provide a thermal management scheme which works perfectly at all phases of the flight. The goal of this present paper is to use the principle of buoyancy-driven flows to provide cooling for the rotor. Buoyancy driven flows are caused by the variation of the density with body forces (gravity field, Coriolis force, and centrifugal force). At high rotational speeds, Coriolis and centrifugal forces become dominant in rotating systems. The novelty of this current paper lies in using rotation induced buoyancy to cool the rotor of electric machines.