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July 13, 2013, 07:41 |
Non-uniform heat flux on a tube
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#1 |
Member
Join Date: Sep 2011
Posts: 39
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Dear all,
How can I use a non-uniform heat flux boundary condition along the circumference of a tube? Regards |
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July 19, 2013, 08:11 |
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#2 |
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July 19, 2013, 09:08 |
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#3 |
Super Moderator
Alex
Join Date: Jun 2012
Location: Germany
Posts: 3,399
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With the define_profile macro you should be able to specify such a boundary condition.
Code:
#include "udf.h" DEFINE_PROFILE(heatflux,t,i) { real x[ND_ND]; face_t f; begin_f_loop(f,t) { F_CENTROID(x,f,t); F_PROFILE(f,t,i) = 1.0; *instead of 1.0, define whatever spatial function you want *x[1] is the x-coordinate, x[2] the y-coordinate and x[3] the z-coordinate } end_f_loop(f,t) } |
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July 19, 2013, 09:14 |
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#4 |
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Join Date: Sep 2011
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Dear Alex,
Thanks a lot for this. I will try it out. so i do not need to worry about converting the cartesian coordinates to cylindrical coordinates? The heat flux varies only in the circumferential direction and not in the radial or axial direction. Regards Kamu |
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July 19, 2013, 09:17 |
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#5 |
Super Moderator
Alex
Join Date: Jun 2012
Location: Germany
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If your simulation is real 3D then there should be no problem.
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July 13, 2016, 00:25 |
Non-uniform heat flux on a tube
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#6 |
New Member
Jharkhand
Join Date: Jul 2015
Posts: 5
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above program is not running and what is the meaning of x[1],y[1] and z[1].
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July 13, 2016, 04:28 |
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#7 |
Super Moderator
Alex
Join Date: Jun 2012
Location: Germany
Posts: 3,399
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"program not running" is not an error description to work with.
There is no x[1], y[1] and z[1] in the code. As the comment lines say, the array x holds the position vector. Thanks to my fortran background I shifted the indices. The comment line should read: Code:
*x[0] is the x-coordinate, x[1] the y-coordinate and x[2] the z-coordinate |
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August 2, 2019, 06:14 |
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#8 |
New Member
Join Date: Jul 2019
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hi can you tell me what's the heat flux function you've defined mathematically as non-uniform heat flux?
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August 2, 2019, 08:01 |
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#9 |
Senior Member
Alexander
Join Date: Apr 2013
Posts: 2,363
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Code:
#include "udf.h" DEFINE_PROFILE(heatflux,t,i) { real x[ND_ND]; face_t f; begin_f_loop(f,t) { F_CENTROID(x,f,t); F_PROFILE(f,t,i) = 1.0; *instead of 1.0, define whatever spatial function you want *x[0] is the x-coordinate, x[1] the y-coordinate and x[2] the z-coordinate } end_f_loop(f,t) } Code:
F_PROFILE(f,t,i) = x[0]*1000.0; heat source could be time dependent as well best regards |
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August 16, 2019, 02:42 |
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#10 | |
New Member
Join Date: Jul 2019
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Quote:
I m working on a pipe in pipe volumetric solar collector and I want to choose best radiation model in ansys fluent because my multiphase model is mixture for simulating nanofluid and my solver is pressure based you know when I read papers related to this topic I found that monte carlo method (density based) is a proper model and using udf file to consider non uniform radiation is applied so what should I do ?I cant change to monte carlo method because mixture model is important for me... |
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August 18, 2019, 22:18 |
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#11 |
Senior Member
Alexander
Join Date: Apr 2013
Posts: 2,363
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from my point of view monte carlo method is just a slover, use other one
write new paper best regards |
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