Reply To: Importing the working torque into UDF

[sdarmayuda]

Hallo everyone,

I have found how to retrieve the torque from Fluent. However, there is still error in the code after I intepreted the UDF code. it says "line 14: parse error". I think it is about the macro DEFINE_TRANSIENT_PROFILE. Can somebody help to show me the mistakes about this macro? Thank you very much.

Here is my UDF Code:

**************************************************************************

#include "udf.h"

DEFINE_ON_DEMAND(wall_forces) 

{ 

Domain * domain = Get_Domain (1); /* For multiphase flow, you need to set the Sub domain */ 

Thread *t; 

real CG[3], force[3], moment[3]; 

t = Lookup_Thread (domain, 13); /* 13 is the ID of the wall to be determined. */ 

NV_S (CG, =, 0.0); /* coordinates of the center position to find the moment. */ 

Compute_Force_And_Moment (domain, t, CG, force, moment, TRUE); 

Message("f=(%e, %e, %e), m=(%e, %e, %e)n", force[0], force[1], force[2], moment[0], moment[1], moment[2]); 

/* force [0], force [1], force [2] are respectively x, y, z-direction forces, Is the sum of the force by the force and the shear stress due to pressure. */ 

}

 

DEFINE_TRANSIENT_PROFILE(testudf, CURRENT_TIME)

{

real omega_ts=0.0; /*starting omega*/

real omega_tf=600.0; /*final omega*/

real Jt=0.000554; /*Moment Inertia of the Turbin*/

real delta_t=0.0001; /*delta t simulation*/

real CURRENT_TIMESTEP;

real CURRENT_TIME;

real alpha_t; /*angular acceleration*/

Thread *t;

cell_t c;

t=Lookup_Thread(domain,9); /*Cell Zone ID = 9*/

 

begin_c_loop (c,t)

{

alpha_t= 15*moment[0]/Jt; /*there are 15 blades, x axis as rotation axis*/

omega_ts+=alpha_t*CURRENT_TIMESTEP;

 

if (omega_ts > omega_tf)

{omega_ts = omega_tf;}

 

THREAD_VAR(t).fluid.omega=omega_ts;

}

end_c_loop (c,t)

 

}