[husywfl]

Hi everyone,

I want to use the fixed value function to fix the velocity of some cell (marked as C_UDM=0).

Once I used the fixed value function the velocity of whole zone was fixed, not the specified cell.

Please somebody help me how to realize it with UDF.

Thank you very much.

husywfl

[AlexanderZ]

How do you define the cell,where you want to fix velocity?
post your code here

best regards

[husywfl]

Originally Posted by AlexanderZ

How do you define the cell,where you want to fix velocity?
post your code here

best regards

Hi Alexander,

Thank you for your reply.

My code:

DEFINE_ADJUST(adjust_fix,d)
{
Thread *t;
cell_t c;

thread_loop_c(t,d)
{
begin_c_loop_all(c,t)
{
if (C_UDMI(c,t,0) == 1.)
{
C_U(c,t) = 0.;
C_V(c,t) = 0.;

#if RP_3D
C_W(c,t) = 0.;
#endif

}
}
end_c_loop_all(c,t)
}
}

For example, I want to fix the red zone (Fig.1) marked as UDM=1 with zero velocity, whick means the flow will be blocked.

But the results (Fig.2) shows the marked zone still have velocity, and the flow before and after the zone is not effected.

Please help me.

Thank you.

Husywfl

[AlexanderZ]

is porous zone is suitable for your simulation?

best regards

[ArikGuyz]

Dear husywfl,

Would you be able to solve this problem? Do you succeed to specify zero velocity to this specific region?

If you, may you share with me how did you do that?

Thanks,

[engie]

I think following macro's

C_U(c,t) = 0.;
C_V(c,t) = 0.;

are only available to access data.

In mem.h, they are defined as

#define C_U(c,t)C_STORAGE_R(c,t,SV_U)

and I assume the "R" stands for "Read", so my bet is that fixing variables this way is not possible.