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Condensation in a closed thermosyphon??? (heat pipe, evaporation-condensation)) |
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October 20, 2014, 19:59
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Condensation in a closed thermosyphon??? (heat pipe, evaporation-condensation))
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#1 |
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New Member
Xiaobing Zhang
Join Date: Apr 2014
Posts: 12
Rep Power: 12  |
Hello,
I'm modeling phase change flow in a closed thermosyphon. Now my status is having evaporation in my evaporator. But little condensation is found in the cold part. The following pics are my results. I calculated 200s already, but condensation is still very small. Any guidance or help will be appreciated. Thanks, Xiaobing  Limited condensation happens in the condenser.  Limited condensation happens in the condenser.  Evaporation is good. |
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April 7, 2015, 16:19
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Udf
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#2 |
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Member
Muhammed Asmail
Join Date: Nov 2009
Location: Iraq
Posts: 43
Rep Power: 17 |
did you use UDF for heat and mass transfer ??
i am not get on condensation ??!!! i do not know why? |
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December 12, 2015, 23:35
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evaporation condensation in fluent
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#3 |
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Member
Ram Kumar Pal
Join Date: Apr 2015
Posts: 38
Rep Power: 11 |
Hello friends, I have written UDF for phase change in thermosyphon, boiling is happening inside evaporator but there is no condensation inside condenser, I'm confused why this error is happening. I'm writing UDF below, please notify me what is the error in UDF.
#include "udf.h" #include "sg_mphase.h" #include "mem.h" #include "metric.h" #include "flow.h" #include "sg.h" #define T_SAT 373 #define LAT_HT 2455e3 DEFINE_SOURCE(vap_src,cell,pri_th,dS,eqn) { real m_dot_v; Thread *mix_th, *sec_th; mix_th = THREAD_SUPER_THREAD(pri_th); sec_th = THREAD_SUB_THREAD(mix_th,1); /*m_dot_v=0.0;*/ if (C_T(cell,mix_th)>T_SAT) { m_dot_v = 0.1*C_VOF(cell,sec_th)*C_R(cell,sec_th)*(C_T(cell, mix_th)-T_SAT)/T_SAT; dS[eqn] = 0.0; } else if (C_T(cell,mix_th)<T_SAT) { m_dot_v = -0.1*C_VOF(cell,pri_th)*C_R(cell, pri_th)*(T_SAT-C_T(cell,mix_th))/T_SAT; dS[eqn] = -0.1*C_R(cell,pri_th)*(T_SAT-C_T(cell,mix_th))/T_SAT; } return m_dot_v; } DEFINE_SOURCE(liq_src,cell,sec_th,dS,eqn) { real m_dot_l; Thread *mix_th, *pri_th; mix_th = THREAD_SUPER_THREAD(sec_th); pri_th = THREAD_SUB_THREAD(mix_th,0); /*m_dot_l=0.0;*/ if (C_T(cell,mix_th)>T_SAT) { m_dot_l = -0.1*C_VOF(cell,sec_th)*C_R(cell,sec_th)*(C_T(cell, mix_th)-T_SAT)/T_SAT; dS[eqn] = -0.1*C_R(cell,sec_th)*(C_T(cell,mix_th)-T_SAT)/T_SAT; } else if (C_T(cell,mix_th)<T_SAT) { m_dot_l = 0.1*C_VOF(cell,pri_th)*C_R(cell,pri_th)*(T_SAT-C_T(cell,mix_th))/T_SAT; dS[eqn] =0.0; } return m_dot_l; } DEFINE_SOURCE(enrg_src,cell,mix_th,dS,eqn) { real enrg_dot; Thread *pri_th, *sec_th; pri_th = THREAD_SUB_THREAD(mix_th,0); sec_th = THREAD_SUB_THREAD(mix_th,1); if (C_T(cell,mix_th)>T_SAT) { enrg_dot = -0.1*C_VOF(cell,sec_th)*C_R(cell,sec_th)*LAT_HT*(C_ T(cell,mix_th)-T_SAT)/T_SAT; dS[eqn] = -0.1*C_VOF(cell,sec_th)*C_R(cell,sec_th)*LAT_HT/T_SAT; } else if (C_T(cell,mix_th)<T_SAT) { enrg_dot = 0.1*C_VOF(cell,pri_th)*C_R(cell,pri_th)*LAT_HT*(T_ SAT-C_T(cell,mix_th))/T_SAT; dS[eqn] = -0.1*C_VOF(cell,pri_th)*C_R(cell, pri_th)*LAT_HT/T_SAT; } return enrg_dot; } |
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December 14, 2015, 10:22
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Udf
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#4 | |
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Member
Muhammed Asmail
Join Date: Nov 2009
Location: Iraq
Posts: 43
Rep Power: 17 |
Dear rampal
your Ansys-Fluent is original version?? I mean original from the company no commercial that it is bought from the market case of heat pipe is very complex and it needs original license and the condensation will not appear to you if the Ansys not original version as it happened with me through 8 months and i did not get result Ansys can solve simple cases if it is not original version but heat pipe is complex case and it needs original version i hope that you understand me many thanks Mohammed Quote:
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June 17, 2016, 10:43
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#5 | |
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New Member
SHUJAN
Join Date: Jun 2016
Posts: 17
Rep Power: 10 |
Quote:
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July 5, 2016, 13:47
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#6 | |
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Senior Member
Przemek
Join Date: Jun 2011
Posts: 249
Rep Power: 16 |
Quote:
Can you send errors you got?
__________________
best regards pblasiak |
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July 14, 2016, 13:02
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#7 | |
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Senior Member
Przemek
Join Date: Jun 2011
Posts: 249
Rep Power: 16 |
Quote:
Did you model this with UDF or built-in Fluent model?
__________________
best regards pblasiak |
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July 27, 2016, 12:37
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#8 | |
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Senior Member
Przemek
Join Date: Jun 2011
Posts: 249
Rep Power: 16 |
Quote:
Have you solved your problem with no condensation? I have the same problem. Please see here: http://www.cfd-online.com/Forums/flu...on-doesnt.html
__________________
best regards pblasiak |
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October 18, 2016, 14:18
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#9 |
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New Member
Join Date: Oct 2016
Location: Ringkobing, Denmark
Posts: 10
Rep Power: 10 |
Anyone succeed to simulate the heat pipe evaporator and condenser?
I'm doing my bachelor project on it and i will appreciate any help in this case because, i'm beginner with fluent however, i know the equations of energy and momentum which need to be written in the udf but i failed to simulate it. |
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December 21, 2016, 12:25
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Heat Pipe
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#10 |
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New Member
Reza
Join Date: Dec 2016
Posts: 2
Rep Power: 0 |
Hi everyone. I am new in the two-phase flow and heat pipe field and I should simulate a wicked heat pipe by OpenFoam. It is appreciated if anyone can help me ... Thanks
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