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UDF for modelling heat loss in 2D

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Old   June 18, 2010, 02:54
Default UDF for modelling heat loss in 2D
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Shrinand Iyer
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HI. I need help on how to construct a UDF, which can account for heat loss in a 2D channel. Thus effectively it will model 3D results from the 2D.

More details-http://FastFreeFileHosting.com/file/40127/UDf-bmp.html

Last edited by Shrinand; June 18, 2010 at 03:14.
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Old   February 29, 2016, 06:47
Default heat loss through walls
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s.p.gupta
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#include "udf.h"
#include "math.h"
#include "sg.h"

DEFINE_PROFILE(HTCh, t, i)
{
face_t f;
Thread *tco;
cell_t co; /**thread data**/
real Tc=0; /**centraoid temperature of cells **/
real Ts2=0; /** secondary side temperature for Grashof no **/
real q=0; /** heat flux at face **/
begin_f_loop(f, t)
{
Ts = F_T(f,t);
co =F_C0(f,t);
tco=THREAD_T0(t);
Tc=C_T(co,tco);
BOUNDARY_FACE_GEOMETRY(f,t,A,ds,es,A_by_es,dr0);
area = sqrt(A[0]*A[0]+A[1]*A[1]+A[2]*A[2]);
theta=area/A_by_es;

q=kl*abs(cos(theta))*(Tc-Ts)/ds;

Ts2=Ts-(log(d/di)*q*di/(2*ki)); //for cylinder
// Ts2=Ts- abs(dt*q/ki); // for rectangular slab
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Old   February 29, 2016, 06:50
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This code will work better at solid meshed surface, but if u wish to use if fluid region you have to consider convective and transient energy terms too.
"Ts2" will give insulated body temperature, if u don't have insulation you can use directly "Ts" to calculate Gr number and using that u can relate with heat transfer coefficients.

Last edited by shri2802; March 3, 2016 at 07:25.
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