Learning Forum

[loganszajnecki]

Dear colleagues,

I am trying to implement an x-momentum source term on a background grid using Fluent UDFs. See my source term below:

DEFINE_SOURCE(ALM,c,t,dS,eqn)

{

real xc[ND_ND];

real con, source;

C_CENTROID(xc,c,t);

source = C_UDSI(c,t,0);

dS[eqn] = 0;

return source;

}

Where C_UDSI(c,t,0) is a user defined scalar that is determined using an adjust macro. The value of C_UDSI(c,t,0) is a Gaussian distribution acting for a given region of cells and its implementation is presumably correct.

I am encountering issues with the source term implementation. Specifically, there is no change to the flow field when activating the source term. It is as if the source term is being neglected entirely; it introduces no change to the velocity of the flow in the defined region where UDS-0 acts. Any help would be appreciated. Thank you.

[Rob]

If you plot the scalar what do you see? Remember the source you're adding is N/m3 so make sure the scalar value is big enough to be seen by the flow.

[Amine Ben Hadj Ali]

If you are not linearizing the source term so why not just using Fluent Expression to apply the source and here you can even visualize and easily debug....