Flow and Heat Transfer Between Rotating Sphere and Eccentric Coaxial Spherical Annuli Heat Sink

This document provides a new heat transfer method, i.e. hydrodynamic air-gap heat transfer to transfer the heat from the rotating sphere. The surface of the heat sink is designed as spherical, and positioned at a position from the sphere, so that the narrow wedge shaped air gap is formed between heat sink and rotating sphere. When the sphere is rotating, the hydrodynamic is formed in the narrow air gap, and can be used to transfer heat effectively. Firstly, the heat transfer model of the wedge shaped narrow air gap is theoretically established based on the Reynolds equation and energy equation, and their according characteristics are evaluated based on the numerical calculation. Case studies for rotating speed and eccentricity were quantitatively investigated, and showed great effect.