Uniaxial Model for Gas-Loaded Variable Conductance Heat Pipe Performance in the Inertial Flow Regime

摘要

A model which accounts for diffusion at the vapor/gas interface as well as for inertial effects of the moving vapor is presented. Calculations show that the diffusion effects are of minor importance in comparison with the inertial effects, which can be considerable in a certain part of the VCHP operating range. For working fluids with relatively low vapor pressure (such as methanol, freons, liquid metals) this part of the operating range is the wide sonic regime; for other working fluids it is confined to temperatures near freeze out conditions. Results of calculations performed with an improved flat front model, derived from the uniaxial model by taking the limit or zero diffusivity, are given. These results predict VCHP performance and controllability figures significantly different from those obtained from the classical flat front theory, where inertial effects are neglected.