initialising a thermal boundary layer at interface using funkySetFields
 

Hi all,

I am using interThermalPhaseChangeFoam to model a growing vapour bubble in a superheated liquid that can achieve results as shown in the following image.

https://www.mdpi.com/energies/energi...00272-g004.png

Apologies for the enlarged image.

I have initialised the bubble using funkysetfields by using the following code.

initFieldAlpha
{
field alpha1;
expression "1";
keepPatches true;
}
initTemp
{
field T;
expression "378.15";
keepPatches true;
}
alpha1.org
{
field alpha1;
expression "0";
condition "pow(pos().x-0,2) + pow(pos().y-0,2) < pow((0.1E-3),2)";
keepPatches true;
}
BubbleTemp
{
field T;
expression "373.15";
condition "pow(pos().x-0,2) + pow(pos().y-0,2) < pow((0.1E-3),2)";
keepPatches true;
}


However, I am trying to initialise a thermal layer around the interface of the bubble by the equation as shown in the image using the equation.

δT = r(T = Tsat + 0.99(T∞ −Tsat)) −R0

where δT is initial thermal layer thickness (7.00 × 10−6)

R0 is initial bubble radius

It is suggested that the initial thermal boundary layer is to be misplaced about 1-2 cells outside the bubble interface on the liquid side.

I am unsure whether this can be achieved by funkysetfields or groovyBC or through codeStream.

Thanks for spending the time looking at my problem. If i need to provide you with more information please let me know.

Hey guys,

Does anyone have any suggestions/guidance for this problem?

Anyone have any ideas, getting a bit desperate here :confused:. My knowledge so far, suggests that I use groovyBC however I'm unsure how to define the thickness of the boundary.

Hi Sam,
Can you please tell me how you have initialized the temperature field (thermal boundary layer) in this pool boiling case. If possible can you share your test case?


Thank you

Hi Nikhil,

Apologises I haven't been able to complete this. My project changed and I ended up doing something else.

A way to do it is to initialise a space between the bubble and the liquid using the > and < commands.

So added another two set of commands for the alpha field and the temperature field for the area when the bubble is greater than the radius and when the interface is between the bubble and liquid.

I hope it makes sense to you.

Hi Sam,
Thank you for the suggestion, I will try to implement this. Also in one of your page you posted that you converted interThermalPhaseChangeFoam for the newer version. If possible can you share that updated solver.


Thankyou

Apologies for the late reply.

I have found a link for interThermalPhaseChangeFoam for a updated version 6.

https://github.com/Swagga5aur/interThermalPhaseFoam

I hope this helps as mine differs greatly from the original solver.

Hi Sam,
Thankyou for your reply and suggestion for the updated version of interThermalPhaseChangeFoam.