Abstract
A numerical study is conducted on the vapor and
liquid flow in a wick structure of an axially rotating heat pipe.
For the vapor, the governing equations are the Navier-Stokes.
For the liquid a space average of the Navier-Stokes equation is
performed and a porous media model is introduced for the cross
correlation that appears from the averaging process. A control
volume approach on a staggered grid is used in the development
of the computer program. Suction and blowing velocities are
used as boundary conditions of the vapor and liquid, which are
related to a local heat flux input in the evaporator section, and
local heat flux output in the condenser section, respectively.
The aim behind this study is the application of heat pipes in
drilling applications. A triangular heat flux distribution is
assumed in the evaporator due to the higher heat flux generated
at the tip of the drill. A parametric study is conducted to analyze
the effect of different parameters such as rotational speeds,
saturation conditions, porosity, permeability and dimensions of
the wick structure in the porous medium. These parameters
significantly affect the pressure drop in the heat pipe and allow
predicting failure conditions, which is critical in the design of
heat pipes in drilling applications. The results of this study will
be useful for the complete analysis of the heat pipe performance
including the solution of the heat transfer on the solid wall as a
conjugate problem.