The effects of liquid-vapor coupling and non- Darcian transport on asymmetrical disk- shaped heat pipes

Abstract---In this work a pseudo-three-dimensional analytical model is developed for the steady incompressible vapor and liquid flow in an asymmetrical disk-shaped heat pipe. The hydrodynamic coupling of the vapor and liquid flow, the gravitational effects and the effects of non-Darcian transport through the porous wick are incorporated in the model, and the variations in upper and lower liquid velocity and pressure distributions are accounted for. The asymmetrical vapor and upper and lower liquid velocity profiles, the vapor and upper and lower liquid pressure distributions and the interface temperature distribution accounting for the vapor liquid coupling and the non-Darcian effects are obtained. The effects of the vapor-liquid coupling, upper and lower liquid velocity and pressure fields and boundary and inertia in altering the limiting heat pipe heat transfer performance are discussed and assessed. Finally, the analytical results are compared with the available experimental data and are found to be in good agreement. Copyright © 1996 Elsevier Science Ltd.