Learning Forum

[jmt714]

Hi! 

I am trying to compile the following UDF:

#include "udf.h"
 
 
int last_ts = -1;
 
 DEFINE_GRID_MOTION(mitral_movement,domain,dt,time,dtime)
 {
    Thread *tf = DT_THREAD(dt); /* zone */ 
    face_t f; /* faces*/
    Node *v;
    real NV_VEC(axis), NV_VEC(dx);
    real NV_VEC(origin);
    double displ[105] = {-2.31110880000000e-05, -5.78353680747664e-05,  -5.87595468992113e-05,  -6.46174026334990e-05,  -0.000103825859674563,  -0.000217079075525136,  -0.000256401435192825,  -0.000275866756577904,  -0.000358596163999863,  -0.000308366495539297,  -0.000319002682794429,  -0.000349618421760680,  -0.000349129134802423,  -0.000300145791513366,  -0.000314688030776492,  -0.000344275931036111,  -0.000314687932121784,  -0.000314656644654236,  -0.000314656753976871,  -0.000322590075194713,  -0.000308334554732122,  -0.000326125198519708,  -0.000307366719488318,  -0.000308929159594051,  -0.000329482076917630,  -0.000338576347580837,  -0.000299061755676187,  -0.000300230079537407,  -0.000253449986499882,  -0.000198312769317913,  -0.000180340556903472,  -0.000112397338561133,  -8.40003618339527e-05,  -7.77792472565544e-05,  -7.88121189048852e-05,  -0.000104891305927779,  -0.000119703840000000,  -0.000104687803423177,  -5.93107999770712e-05,  -2.91863885997525e-05,  1.21481359999986e-05,   7.89120094802929e-05,   0.000151316152702385,   0.000284436240311541,   0.000359121893179136,   0.000314656460656127,   0.000299841953976870,   0.000251261035685624,   0.000255425054236490,   0.000289177263771537,   0.000318807335756432,   0.000315266920243571,   0.000380260120398392,   0.000421821689890560,   0.000590536034702553,   0.000763826675008497,   0.000607407407999999,   0.000575424127331443,   0.000466356689754228,   0.000179550340995987,   4.74094579183375e-05,   0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  0,  3.00247079537410e-05,   3.49618091102193e-05,   9.08748293603945e-06,   0,  0,  4.91856954448908e-05,   0.000100144131885768,   0.000161188712669342,   0.000235867164603402,   0.000330651455396601,   0.000412044074505546,   0.000294341911446777,   0.000247095542047674,   0.000125480123400247,   1.43715885997522e-05,   -4.85880332094179e-05,  -0.000104893294790583,  -0.000159999839999999,  -0.000138667891727386,  -7.52536644170562e-05,  -9.24489918555579e-05,  -5.52571190150475e-05,  -6.97790502339493e-05,  -6.87452874203444e-05,  -0.000101185005521489,  0.000796299778190831,   0,  0,  0,  0};
    int n;
    int curr_ts;
        curr_ts = N_TIME;

    /* set deforming flag on adjacent cell zone */
    SET_DEFORMING_THREAD_FLAG(THREAD_T0(tf));
    /*NV_S(omega, =, 0.0); */
    NV_D(axis, =, 1.0, 0.0, 0.0);
    NV_D(origin, =, 0.0, 0.0, 0.0);
    begin_f_loop(f,tf)
    {
       f_node_loop(f,tf,n)
       {
        v = F_NODE(f,tf,n); /*function that pickes up the node */ 
        /* update node if x position is greater than 0.02    
        and that the current node has not been previously
        visited when looping through previous faces */
        if (last_ts != curr_ts && NODE_POS_NEED_UPDATE (v))
        {
         /* indicate that node position has been update
         so that it’s not updated more than once */
         
         
         last_ts = curr_ts;
         NODE_POS_UPDATED(v);
         NV_V_VS(NODE_COORD(v),=, NODE_COORD(v),+, axis,*,displ[last_ts]);
        }
     }
  }
  end_f_loop(f,tf);
 } 

And I get this error: LINK : fatal error LNK1104: cannot open file 'libudf.dll'.


I don't know if it is because of my udf function that is wrong coded, or because it lacks some compiler. 

Thank you very much in advance!

 

 

[Rob]

What else did Fluent output when the UDF failed to compile?  Was there anything about nmake? Have you got (and linked) a compiler on your computer? 

[DrAmine]

To add to rwoolhou message: check if you have already an UDF loaded into your case!

[CFDGer]

I actually have the same question regarding a UDF for my specific heat cp(T).
I receive a similar error message:
LINK : fatal error LNK1104: cannot open file "kernel123-lib".


I don't receive the warning regarding the nmake.
I use FLUENT 2020R1 and the current Microsoft Visual Studio Community.
I have read something about some Environment Variables but I'm not sure what to do exactly.
Thanks

[DrAmine]

Can you compile this one:
#include "udf.h"
DEFINE_ON_DEMAND(Hello)
{
Message0("nHello World!n");
}

[CFDGer]

Thanks for your reply!
No, unfortunately this doesn't work aswell.
I already checked the Ansys Customer Portal and the case numbers
#2041677
and
#2061708
But I couldn't find any of the mentioned environment variables on my system.
What does this all mean now?

[DrAmine]

What about launching from the x64-86 VS command prompt as indicated in the solutions?

[CFDGer]

I don't know what to enter in that command prompt. I mean, which folder or file am I supposed to cd to? The FLUENT .exe?

[DrAmine]

Check #2059458

[CFDGer]

That works. I am now able to Build and Load the Compiled function, thanks!
But I can't open FLUENT this way all the time. Is this problem fixed now that I have done it this way once or do i always have to start FLUENT like this if I want to implement one or more UDFs?

[CFDGer]

Well, now that I tried that exact procedure a second time it says "nmake" can't be found.

[Rob]

If you can update to R2 there's an inbuilt compiler: try that.

[DrAmine]

Yes the best solution.

[anshs]

Hello Dr. Amine can you help me with a mass transfer udf problem :

My UDF for mass transfer is not running , the code stops at "Message("nn %f," , NV_MAG(C_VOF_G(cell,w)) );"



UDF:  

DEFINE_MASS_TRANSFER(interface_transfer, cell, thread, from_index, from_species_index, to_index, to_species_index)

{

real m_lg;

Thread *w = THREAD_SUB_THREAD(thread, from_index);

Thread *o = THREAD_SUB_THREAD(thread, to_index);

m_lg = 0.0;

if ( ( C_VOF(cell,w)*C_VOF(cell,o) > 0.1 ) && (C_VOF(cell,w) + C_VOF(cell,o) >0.75) )



{

Message("nn %f," , C_YI(cell, w, 0));

Message("nn %f," , ( C_YI(cell, w, 0) - 0.00005 ));

Message("nn %f," , NV_MAG(C_VOF_G(cell,w)) );

m_lg = 0.4 * (NV_MAG(C_VOF_G(cell,w)))* ( C_YI(cell, w, 0) - 0.00005 ) ;

}

else m_lg = 0.0 ;

return (m_lg);

}

[Karthik R]

Hello Please create a new post for each new discussion for better visibility on your issue.
If you add a message line to print M_lg, what you do get?
Thanks.
Karthik

[CFDGer]

Hi Amine and Rob, ok I will try R2. Thanks

[DrAmine]

I will close this thread. please try R2 and report on your experience with the inbuilt Slang compiler ;)