Momentum source UDF

Matthew Brannock

Hi, I've just written up some code for a momentum source compiled UDF, where the constant source is restricted by its position in the domain and is adjusted on each iteration. It compiled OK (which doesn't mean much) but I get an error when fluent tries to call the function:

Error: get_udf_function: function cell_x_source has wrong type: 5 != 3 Error Object: ()

What does this mean and how can I fix it? I am a novice at C programming so it is probably something majorly wrong with the variable and function types I'm using. Here's the code:

#include "udf.h"

/* ------------------------------------------------------------------------

X_Momentum_Source

This routine returns the source term for the X-momentum term for each

control volume in the domain.

------------------------------------------------------------------------ */ DEFINE_SOURCE(cell_x_source, cell, thread, dS, eqn) {

real source;

real xc[ND_ND]; /* 3D position in array */

C_CENTROID(xc,cell,thread); /* outputs xc (cell centroid) */

if (xc[0] > 0.95)

{

if (xc[0] < 1.05)

if (xc[1] > 0)

if (xc[1] < 1) /* Restricted position of momentum source */

/* source term */

source = 0.1;

/* derivative of source term w.r.t. x-velocity. */

dS[eqn] = 0;

}

else

source = dS[eqn] = 0.; return source; }