[Kanarya]

thanks. no it is not working in parallel. what do you mean with thread ID?
I am using this one like ID "if( THREAD_ID(mixture_thread) == 4 )"
and it works in serial perfect but not in parallel.

thanks

Originally Posted by zwbmimi

Hi, i include the thread id in source terms of my uds. Does your code work well in parallel without the tread id? I'm happy to help.

[Kanarya]

are you using auto-partitioning or manual one?
thanks...

Originally Posted by Kanarya

thanks. no it is not working in parallel. what do you mean with thread ID?
I am using this one like ID "if( THREAD_ID(mixture_thread) == 4 )"
and it works in serial perfect but not in parallel.

thanks

[zwbmimi]

Hi Kanarya,

My code is like this,
DEFINE_SOURCE(source_1,c,t,dS,eqn)
{
int aaa = 4;

...

if (THREAD_ID(t) == aaa)
{
...
}
}
where t is the thread passed by FLUENT UDF Marco.

Originally Posted by Kanarya

are you using auto-partitioning or manual one?
thanks...

[Kanarya]

are you using auto-partitioning or manual one?
thanks...

Originally Posted by zwbmimi

Hi Kanarya,

My code is like this,
DEFINE_SOURCE(source_1,c,t,dS,eqn)
{
int aaa = 4;

...

if (THREAD_ID(t) == aaa)
{
...
}
}
where t is the thread passed by FLUENT UDF Marco.

[zwbmimi]

Hi Kanarya,

Do you mean define the zones in geometry? Actually, my geometry has many zones. I define them when I drawn it.

Originally Posted by Kanarya

are you using auto-partitioning or manual one?
thanks...

[Kanarya]

No. You parallelise it when you start the Fluent or after starting it.

Originally Posted by zwbmimi

Hi Kanarya,

Do you mean define the zones in geometry? Actually, my geometry has many zones. I define them when I drawn it.

[zwbmimi]

It should be auto partitioning.

Originally Posted by Kanarya

No. You parallelise it when you start the Fluent or after starting it.

[Kanarya]

thanks a lot..I will try to deal with this!!

BEst regards...

Originally Posted by zwbmimi

It should be auto partitioning.

[Bharadwaj B S]

Originally Posted by truffaldino

Hello Nathan,

Yes I have solved the problem but it was a long time ago: I remember that it turns out that zone ID numbers must be taken as assigned by gambit (as in mesh file) and not as shown by fluent! That is why my procedure was not working. So, in file I have presented above, it was necessary to change values of idtop and idbottom to those given by gambit in mesh file.

Truffaldino

Hi everyone,

I am getting ACCESS VIOLATION ERROR, when I Initialize my case (WITH AN UDF FOR MASS FLUX).

This error, as I have came across is because of using a parameter which is not present or given in FLUENT (my case F_T(f, t) i.e, face temperature).

In my case I have used t = Lookup_Thread(d, ID). I have taken the ID from FLUENT BOUNDARY CONDITION PANEL. And my mesh was generated using ICEM CFD.

QUESTION:

How do you find out the ZONE ID in ICEM CFD????

I really have very less idea regarding GAMBIT.
Any help is of great use. Thanks in advance.

Bharadwaj

[pakk]

Your problem is that the Fluent UDF tries to read face temperatures that don't exist.

Why do you want to find the zone id in ICEM CFD???

(That is like saying: "I have a problem with my car, it will not start. How do I get the serial number of my telephone?")

[Bharadwaj B S]

Originally Posted by pakk

Your problem is that the Fluent UDF tries to read face temperatures that don't exist.

Why do you want to find the zone id in ICEM CFD???

(That is like saying: "I have a problem with my car, it will not start. How do I get the serial number of my telephone?")

Hi pakk,

First of all sorry for confusing. I was confused.

Thanks for your genuine and speedy reply, I was writing a UDF for mass flux from a sphere surface, which is present inside a flow domain.

I was able to write the same. (Thankfully). Just before few minutes ago.

Actually I have used F_T(f, t) as a variable in my flux logic. i.e,
flx = a * F_T(f, t);
where a is just a arbitrary constant.

Its a practice problem which I am doing in order to get grip in writing UDF.

And yes if I use the ZONE ID from FLUENT Boundary conditions tab. I was not able to hook the UDF to the specific sphere.

I opened the mesh in ICEM, while saving the output file in output tab, I gave the required ZONE ID(my case 13). And then I exported the mesh to fluent using Write/output.

Again thanks for your suggestion. I had not switched on the "energy equation", which was giving me an error during initialization. I switched on the energy equation and initialized with BC's (without hooking UDF). Once the case was initialized I hooked the UDF and got the result. Hurray.

[hazari.aaquib]

Dear All,,

I am facing the exact same problem (as previously mentioned, by Truffaldino) with my UDF where the statement if(Thread_ID==...) is ignored in the program.

I have to modify the specific dissipation rate at the interface of a stratified two phase channel flow.
The zone according to fluent is 2 for the interface.

Here is my UDF

# include "udf.h"
DEFINE_ADJUST(adjust_omega, mixture_domain)
{
real xc[ND_ND];
real abcd = 5;
cell_t c;
int ID = 2;
Thread *thread = Lookup_Thread(mixture_domain, ID);
thread_loop_c(thread, mixture_domain)
{
begin_c_loop(c, thread)
{
C_CENTROID(xc, c, thread);
if (THREAD_ID(thread) == ID)
{
C_O(c, thread) = 2927;
}
}
end_c_loop(c, thread)
}

}

According to the previous posts on this thread Truffaldino, solved the same problem (if(Thread_ID)==...) by finding out that gambit had a different values for zone ID than fluent.
I have used ANSYS meshing.

Any suggestions will be appreciated.

[zwbmimi]

Originally Posted by hazari.aaquib

Dear All,,

I am facing the exact same problem (as previously mentioned, by Truffaldino) with my UDF where the statement if(Thread_ID==...) is ignored in the program.

I have to modify the specific dissipation rate at the interface of a stratified two phase channel flow.
The zone according to fluent is 2 for the interface.

Here is my UDF

# include "udf.h"
DEFINE_ADJUST(adjust_omega, mixture_domain)
{
real xc[ND_ND];
real abcd = 5;
cell_t c;
int ID = 2;
Thread *thread = Lookup_Thread(mixture_domain, ID);
thread_loop_c(thread, mixture_domain)
{
begin_c_loop(c, thread)
{
C_CENTROID(xc, c, thread);
if (THREAD_ID(thread) == ID)
{
C_O(c, thread) = 2927;
}
}
end_c_loop(c, thread)
}

}

According to the previous posts on this thread Truffaldino, solved the same problem (if(Thread_ID)==...) by finding out that gambit had a different values for zone ID than fluent.
I have used ANSYS meshing.

Any suggestions will be appreciated.

I think you may use the ID shown in Fluent. It can be found in the Boundary Condition Panel.

[hazari.aaquib]

Hi zwbmimi,

I have used the fluent ID from the boundary conditions panel and even then the commands under if(THREAD_ID==...) is ignored.

Is there any other way?