Simulating Capillary Effect in a heat pipe wick

ruiarahul · February 26, 2019, 06:05

I am doing my 8th semester project on heat pipes.
My project mainly involves simulations on ANSYS.
I have successfully modelled and meshed ( which is the easier part), I am struggling to incorporate the capillary effect in my wick structure.

The heat pipe which I have modelled is a closed system, it contains a vapour flow region enclosed by a wick structure.
The wick structure is in turn enclosed by a copper casing.

I am using the VOF model into incorporate the multiphase effects, along with the K-Epsilon model .
The main problem I am facing is on how to incorporate the capillary effect.
I am currently running a simulation with the following settings in the porous zone :-

1) Homogenous Porosity of 0.55
2) I am using only viscous resistance as the flow in the porous region is laminar.
I have 3 fluids namely air, water and steam.
I have given the same values of viscous resistance for water and steam and higher value for air ( I did this because I did not want air to flow in the porous media).
3) I reversed the direction vectors from 1 to -1 hoping that they will lead to incorporation of the capillary effect.

I am running short of time and am in need of help.
I am willing to pay, if someone helps me solve my problem.

PS : please mail me at ruiarahul5@gmail.com ( for further information)

realCFD · March 10, 2019, 12:32

I think you need to incorporate a body force (momentum source term) for modeling the capillary effect. This would come from some empirical relation (based on wick properties).

amod_kumar · July 13, 2019, 13:16

Did you solve the problem? I think you need to activate surface tension and wall adhesion to activate capillary effect.

February 26, 2019, 06:05	Simulating Capillary Effect in a heat pipe wick	#1
ruiarahul New Member Rahul Ruia Join Date: Feb 2019 Posts: 4 Rep Power: 7	I am doing my 8th semester project on heat pipes. My project mainly involves simulations on ANSYS. I have successfully modelled and meshed ( which is the easier part), I am struggling to incorporate the capillary effect in my wick structure. The heat pipe which I have modelled is a closed system, it contains a vapour flow region enclosed by a wick structure. The wick structure is in turn enclosed by a copper casing. I am using the VOF model into incorporate the multiphase effects, along with the K-Epsilon model . The main problem I am facing is on how to incorporate the capillary effect. I am currently running a simulation with the following settings in the porous zone :- 1) Homogenous Porosity of 0.55 2) I am using only viscous resistance as the flow in the porous region is laminar. I have 3 fluids namely air, water and steam. I have given the same values of viscous resistance for water and steam and higher value for air ( I did this because I did not want air to flow in the porous media). 3) I reversed the direction vectors from 1 to -1 hoping that they will lead to incorporation of the capillary effect. I am running short of time and am in need of help. I am willing to pay, if someone helps me solve my problem. PS : please mail me at ruiarahul5@gmail.com ( for further information)

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March 10, 2019, 12:32		#2
realCFD New Member Join Date: Jun 2013 Posts: 2 Rep Power: 0	I think you need to incorporate a body force (momentum source term) for modeling the capillary effect. This would come from some empirical relation (based on wick properties).

July 13, 2019, 13:16		#3
amod_kumar Member Amod Kumar Join Date: Jan 2010 Location: Delhi, India Posts: 39 Rep Power: 16	Did you solve the problem? I think you need to activate surface tension and wall adhesion to activate capillary effect.