3. Convective transfer in a rotating machine

Evaluating heat transfer in the structure of a rotating machine requires knowledge of the convective transfer characteristics at the various walls of this structure, as well as the heat transport parameters in the cooling channels. These include values for convective exchange coefficients, fluid velocities or flow rates, thermophysical properties (density, thermal conductivity, mass heat, dynamic viscosity) and reference temperature and pressure conditions.

The technologies we're developing are particularly interested in the axial or radial channels present in the stator, between the stator and the casing, in the casing or in the rotor. This is also the preferred region for the air gap, the environment close to the coil heads and the external environment of the housing, whether ventilated or not.

There are a large number of relationships...