# Udf function average temp inlet - outlet

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 March 7, 2011, 15:33 SOLVED:Udf function average temp inlet - outlet #1 New Member   Join Date: Apr 2009 Location: Mexico Posts: 7 Rep Power: 10 Hello, I would appreciate if somebody take a look in the UDF and give me some advices. I am trying to get the average temperature at the outlet of a pipe, and after some manipulations use it in the pressure inlet of the next time step. It compiles and the simulation runs up to the first time step. It starts with reversed flow then just after the first time step prints Temperature limited to 1 in the domain 1. Tavg prints -nan. Thanks DEFINE_EXECUTE_AT_END(Temp_inlet) { Domain *d; real Temp_t; real area; real area_tot; real tavg; real A[ND_ND]; Thread *t; face_t f; d=Get_Domain(1); t=Lookup_Thread(d,11); begin_f_loop(f,t) { area = F_AREA(A,f,t); Temp_t += F_T(f,t); area_tot += area; tavg += Temp_t*area; } end_f_loop(f,t) tavg /= area_tot; tavg_tot1=tavg; printf("\n Tavg = %f\n",tavg_tot1); /*output -nan*/ } DEFINE_PROFILE(Temp_inlet,t,i) { face_t f; real time; real current_time; time=CURRENT_TIMESTEP; current_time=CURRENT_TIME; if (current_time >=10.) { begin_f_loop(f,t) { F_PROFILE(f,t,i)=((fabs(flow_tot)*(tavg_tot-tavg_tot1)*time)/15.)+tavg_tot1; } end_f_loop(f,t) } else { begin_f_loop(f,t) { F_PROFILE(f,t,i)=288.16; } end_f_loop(f,t) } } Last edited by erodv; March 7, 2011 at 20:56. Reason: SOLVED

March 7, 2011, 16:08
#2
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Amir
Join Date: May 2009
Location: Montreal, QC
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Hi,
I think the problem is in your face loop, substitute this and check. hope that help you:
Quote:
 tavg=0; area_tot=0; begin_f_loop(f,t) { F_AREA(A,f,t); AREA=NV_MAG(A); area_tot += AREA; tavg +=F_T(f,t)*AREA; } end_f_loop(f,t) tavg /= area_tot;

 March 7, 2011, 20:54 Solved #3 New Member   Join Date: Apr 2009 Location: Mexico Posts: 7 Rep Power: 10 Thanks Amir, I did your proposed changes and it worked, this thread has been solved .

November 14, 2016, 10:29
#4
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alper yıldırım
Join Date: Feb 2014
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Quote:
 Originally Posted by erodv Thanks Amir, I did your proposed changes and it worked, this thread has been solved .

Hi,

Could u share correct form of the UDF? I am working on similar problem.

Thx

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