A Numerical Model for Transport in Heat Pipes with Different Wick Microstructures Effects

Ram Ranjan, Birck Nanotechnology Center, Purdue University
Jayathi Y. Murthy, Birck Nanotechnology Center, Purdue University
Suresh V. Garimella, Birck Nanotechnology Center, Purdue University
Unnikrishnan Vadakkan, Intel

Date of this Version



A transient, three-dimensional model for thermal transport in heat pipes and vapor chambers is devel- oped. The Navier–Stokes equations along with the energy equation are solved numerically for the liquid and vapor flows. A porous medium formulation is used for the wick region. Evaporation and condensation at the liquid–vapor interface are modeled using kinetic theory. The influence of the wick microstructure on evaporation and condensation mass fluxes at the liquid–vapor interface is accounted for by integrating a microstructure-level evaporation model (micromodel) with the device-level model (macromodel). Meniscus curvature at every location along the wick is calculated as a result of this coupling. The model accounts for the change in interfacial area in the wick pore, thin-film evaporation, and Marangoni con- vection effects during phase change at the liquid–vapor interface. The coupled model is used to predict the performance of a heat pipe with a screen-mesh wick, and the implications of the coupling employed are discussed.


Nanoscience and Nanotechnology