Steady Two-Dimensional Heat and Mass Transfer in the Vapor-Gas Region of a Gas-Loaded Heat Pipe

A numerical analysis is made of the steady two-dimensional heat and mass transfer in the vapor-gas region of a gas-loaded heat pipe. Consideration is given to a cylindrical heat pipe with typical evaporator, condenser, and noncondensible-gas sections and with negligible axial conduction through the wall and the liquid-wick matrix. The elliptical mass, momentum, energy, and species conservation equations have been solved in conjunction with the overall energy and mass conservation constraints and the thermodynamic equilibrium condition for three heat pipe cases with different working fluids and diameters. The results show that in certain gas-loaded heat pipes, such as liquid-metal heat pipes, vapor-gas diffusion and two-dimensionality must be considered in the analysis. Extension of the present numerical framework to more general cases such as including the axial wall conduction is indicated.