Vapor pocket behavior inside the porous wick of a capillary pumped loop for terrestrial application

• A complete dynamic model with unsaturated porous wick is developed.
• The phase change inside the porous wick is described by 2D unsteady model.
• The evaporator conductance is evaluated.
• The dynamic growth of the vapor pocket inside the porous wick is studied.
• The evaporator behavior is analyzed.

This paper presents a numerical study of a Capillary Pumped Loop with an unsaturated porous wick. The CPL model is divided into subsystems, for which transient mass, energy, and momentum balances have been developed. The evaporator is described by a two-dimensional unsteady mathematical model, model which takes into account the existence of a vapor pocket inside the porous wick. The comparison of the numerical results and data experience which makes it possible to validate the proposed model in a transient regime. Simulations show that the vapor pocket size is almost independent of the applied heat load at a steady state. The evaporator behavior is then studied for rapid transient application of heat power, when used in terrestrial applications.