An analysis of the performance of a vertically oriented, gas loaded, variable conductance heat pipe

Abstract

An analysis of steady state operation of a vertically oriented, variable conductance heat pipe is presented. The effects of binary mass diffusion, axial pipe wall conduction, and gravitational effects, caused by the difference in molecular weight of the non-condensible gas and the working fluid are incorporated. Analytical expressions for the conservation of mass, momentum, and energy are combined along with equations of state to describe steady state operation of the heat pipe. These expressions are combined to form a system of three differential equations with three unknowns; working fluid vapor velocity, mass fraction, and temperature. These equations are nondimensionalized and an iteration scheme for numerical solution of the equations is presented .