Evaporation and heat pipes
 

Hello to everyone.

I am new to heat pipes and Fluent and would wish to know whether heat pipe evaporation / condensation phenomena can be simulated for heat pipes?

I started by constructing a regular cylinder with the velocity inlet on the top and used the Mixture Model with mass transfer for evaporation / condensation in order to see the effect as the water flow starts. The inlet temperature was greater than the saturation temperature in order to do the phase-change.

I could see the volume fraction and velocity contour variations with respect to time but could not see any sort of bubbles or slug formation which would convince that the evaporation is taking place.

Would highly apppreciate if anyone might let me know what wrong am I doing. I'm trying to avoid writing a UDF for now. Thankyou again and much appreciated once more.

Hi,

I would assume that the tutorial "Modeling nucleate boiling using FLUENT" is a nice place to start, it is available from fluentusers.com. It also includes some essential UDFs which you get you started in no-time.

Good luck!

-KE

Thankyou for the reply KE. However, I do not have the password for fluentusers (it has been lost by the initial owner) and am unable to get the nucleate or the film boiling tutorial which is causing a worry.

I would highly appreciate if you could let me know how to access the tutorials without fluentusers. Many thanks once again mate.

Hello again,

That is a shame, as there are several useful hints in those tutorials. As an alternative, you could possibly look at the paper "BOILING FLOW SIMULATION IN NEPTUNE_CFD AND FLUENT CODES" by Vyskocil and Macek, available from
http://www.oecd-nea.org/nsd/csni/cfd...boi/BOI-10.pdf

although they do not provide the UDFs used, a detailed description of the theory is given. As far as I can see, this is very close to the theory found in the mentioned tutorial. Hopefully you can find some hints there on how to proceed with your UDFs.

Cheers!

Many thanks mate for the paper. Will definitely read it and have a go again. :)

Hello KE. I did read the paper and got some ideas regarding the theory but I think the tutorials will definitely help my cause here since I require the UDF as well for better understanding. Would it be possible for you to send me the nucleate boiling tutorial package? Your help would be much appreciated certainly.

Thanks

help
 

hi energy,

i'm an undergrad, i'm doing simulation of heat pipe for the evaporation zone for my FYP. So it include boiling. Kindly ask that could you email to me the boiling tutorial that you have receive previously?? i also dun have the username and password for the fluent tutorial (same as your reason) ........
.

I 'm really in desperate stage. Appreciate alot for ur help!!! Thanks in advance if u can email to danieleylai@hotmail.com. Thanks alot!!!:)