Numerical simulation of cylindrical heat pipe considering non-Darcian transport for liquid flow inside wick and mass flow rate at liquid–vapor interface

Abstract

Simulation of a copper cylindrical heat pipe was carried out assuming steady state laminar flow, incompressible flow in liquid-wick and ideal gas incompressible flow in vapor section in three dimensions to estimate the temperature, pressure and velocity profiles. The model used non-Darcian transport through porous wick to determine liquid flow in liquid-wick section. The mass flow rate describes the fluid flow at liquid–vapor interface instead of conjugate heat transfer problem. Heat source of evaporation and condensation was considered in the total enthalpy equation of liquid-wick section to describe the loss and gain of heat from evaporation and condensation. The non-linear algebraic equations from finite volume method discretization were solved by iterative segregation method and the SIMPLEC algorithm. The numerical results of axial outer wall temperature, centerline pressure and velocity magnitude were found to be in good agreement with cylindrical heat pipe operation. The results of axial outer wall temperature and velocity magnitude streamlines are better than the results obtained in earlier studies and the results of axial outer wall temperature are in a good agreement with experimental results. The hypotheses test by two-sample t-test method between the numerical results and experimental results for axial outer wall temperature shows that they are not statistically different.