[wumin]

hello,
I'm new to OpenFoam and have a questions about how to exert a moving heat source on a plate?
It would be great if someone could help me!


Greetings

wumin

[ahmmedshakil]

There are two ways to do that. First, you can consider the heat source is fixed and the material underneath it is moving. This is called fixed co-ordinate system, and this method is good in terms of computational cost.
Second, is the moving co-ordinate system i.e. heat source is moving and work-piece is fixed.
Let, you want to impose a surface heat source. Then the easiest way is to first install groovyBC (which comes with swak4Foam http://openfoamwiki.net/index.php/Contrib/swak4Foam).
Then for,
First method (fixed co-ordinate): imposed as boundary condition

this can be done by imposing groovyBC boundary condition easily.

type groovyBC;
variables "Q;K;";
gradientExpression "Q/K";
fractionExpression "0";

and you have to add the velocity term as : in the governing equation.

Second methodmoving co-ordinate)

 
        type               groovyBC;
        variables       "Q;K;v;";
       gradientExpression "(Q/K)*(pos().x-v*time())"; //just for example
       fractionExpression "0";

These are just for example. I guess now you can easily impose your moving heat source.

cheers,
#shakil

Originally Posted by wumin

hello,
I'm new to OpenFoam and have a questions about how to exert a moving heat source on a plate?
It would be great if someone could help me!


Greetings

wumin

[wumin]

Hi,shakil
Thanks for your reply and contribution.I have installed groovyBC successfully.
My work is mainly to simulate the melting and solidification of selective laser melting（3D printing） ,similar to the laser welding.Do you have some related case of OpenFoam application?
Thank you very much for your help！

[ahmmedshakil]

Hi Wumin,
wow great! I'm working on the similar type of project. I'm working on melting and solidification of Si under laser. Have write anything for that? For melting/solidification you can take help from: http://www.cfd-online.com/Forums/ope...g-problem.html

cheers,
#shakil

[wumin]

Hi shakil,
You are my savior!!I have spent a lot of time on how to exert a moving heat source on a plate.You provide me a solution to this problem.Do you use the method of groovyBC to solve this problem?
or another method？

Greetings ,
wumin

[ahmmedshakil]

Hi,
For implementing laser heat source, I used as explained. For melting problem you can easily picked up the code from http://www.cfd-online.com/Forums/ope...g-problem.html here. That's it.

cheers,
#shakil

[sengerandu]

Dear Shakil and Wumin,

I am also working on Laser welding of Cu/Steel flats and pipes and want to simulate the process in OpenFOAM. My doubt is whether we need to specify a moving group on the face to accept the radiative heat from the laser source.

I am creating the mesh in salome-meca v2013.1. Till now I have created a mesh for the plates attached in butt fashion. Defined some groups of solids for dissimilar metals, some faces for BC. But the doubt is how to give the periodic flux to the surface at the interface.

[jay1234]

Originally Posted by ahmmedshakil

Hi Wumin,
wow great! I'm working on the similar type of project. I'm working on melting and solidification of Si under laser. Have write anything for that? For melting/solidification you can take help from: http://www.cfd-online.com/Forums/ope...g-problem.html

cheers,
#shakil

Dear Ahmedshakil,

Hi i am currently doing laser melting too. Do you have any guide or templates which i can learn from?

Regards,
Jay

[ChristianLackner]

Hello your two,

I have the same problem, however I can not implement it right.
I always get the error code "Cannot find 'value' entry on patch up of field T in file...
... which is requiered to set the value of the generic patch field.
(Actual type groovyBC)

Can someone please tell me what i am most likely doing wrong when i get this error?

PS: I already have written libs("libgroovyBC.so") in the ControlDict, so its not because of that.