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August 20, 2013, 12:40 |
UDF for Back-flow Temperature
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#1 |
New Member
Join Date: Aug 2013
Posts: 10
Rep Power: 13 |
UDF for Back-flow Temperature
hi I'm working on a fluent project and I wrote a UDF and after some iterations it have below error : "temperature limited to 1.000000e+000 in 2203 cells on zone 2 in domain 1 absolute pressure limited to 1.000000e+000 in 659 cells on zone 2 turbulent viscosity limited to viscosity ratio of 1.000000e+005 in 30 cells 663 2.9455e+02 6.5109e-02 1.5233e-01 2.6984e-02 1.8058e-01 7.9374e-01 3.3443e-01 12:18:57 99916 reversed flow in 20 faces on pressure-outlet 7. reversed flow in 2 faces on pressure-outlet 8. temperature limited to 1.000000e+000 in 2871 cells on zone 2 in domain 1 temperature limited to 5.000000e+003 in 321 cells on zone 2 in domain 1 absolute pressure limited to 1.000000e+000 in 563 cells on zone 2 turbulent viscosity limited to viscosity ratio of 1.000000e+005 in 209 cells 664 1.0579e+04 1.2639e-01 2.4408e-01 4.8204e-02 7.2285e+01 9.1977e-01 1.0723e+03 15:24:12 99915 reversed flow in 20 faces on pressure-outlet 7. reversed flow in 7 faces on pressure-outlet 8. temperature limited to 1.000000e+000 in 3562 cells on zone 2 in domain 1 temperature limited to 5.000000e+003 in 537 cells on zone 2 in domain 1 absolute pressure limited to 1.000000e+000 in 589 cells on zone 2 turbulent viscosity limited to viscosity ratio of 1.000000e+005 in 287 cells 665 1.6978e+04 1.1723e-01 1.2709e-01 6.4955e-02 1.2789e+01 7.9988e-01 1.1797e+00 12:19:21 99914 reversed flow in 20 faces on pressure-outlet 7. reversed flow in 9 faces on pressure-outlet 8. temperature limited to 1.000000e+000 in 7932 cells on zone 2 in domain 1 temperature limited to 5.000000e+003 in 13 cells on zone 2 in domain 1 absolute pressure limited to 1.000000e+000 in 231 cells on zone 2 turbulent viscosity limited to viscosity ratio of 1.000000e+005 in 2432 cells 666 3.7511e+04 5.1764e-02 1.3114e-01 1.1729e-01 1.0764e+01 7.9948e-01 3.9790e-01 9:51:28 99913 reversed flow in 20 faces on pressure-outlet 7. reversed flow in 9 faces on pressure-outlet 8. Error: divergence detected in AMG solver: temperature Error Object: () " and that is my udf(x.c)...i used swirl component in it for total temperature i don't know how solve this error anybody can help me?? |
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August 21, 2013, 04:22 |
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#2 |
Senior Member
Paritosh Vasava
Join Date: Oct 2012
Location: Lappeenranta, Finland
Posts: 732
Rep Power: 23 |
These errors indicate that you have poor mesh quality in some regions. Try refining your mesh and give it a try. Also play little bit with the relaxation factors. Either or both of these tricks could help.
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August 21, 2013, 05:37 |
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#3 |
New Member
Join Date: Jul 2013
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i think my udf also is false:
#include"udf.h" realX; realY; DEFINE_ADJUST(XY,domain,t) { real w=0.0004975; face_t f; Domain*domain; Thread*t; cell_tc; intID=20; thread_loop_f(t,domain) { begin_c_loop(c,t) X+=C_R(c,t)*C_U(c,t)*C_VOLUME_2D(c,t)*(C_T(c,t)+w*(C_U(c,t)*C_U(c,t)+C_V(c,t)*C_V(c,t)+C_WSWIRL(c,t)*C_WSWIRL(c,t))); Y+=C_U(c,t)*C_VOLUME_2D(c,t)*C_R(c,t); end_c_loop(c,t) } } DEFINE_PROFILE(BackflowTemp,thread,i) { real s=0.00000001; face_tf; begin_f_loop(f,thread) { F_PROFILE(f,thread,i)=(X)/((Y)+s); } end_f_loop(f,thread) } |
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August 21, 2013, 05:56 |
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#4 |
Senior Member
Paritosh Vasava
Join Date: Oct 2012
Location: Lappeenranta, Finland
Posts: 732
Rep Power: 23 |
DEFINE_ADJUST macro has only two arguments and you have three. Also avoid using names such as X, Y as macro names.
Reading this (http://aerojet.engr.ucdavis.edu/flue...udf/node20.htm) might help. |
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