cylindrical coordinate vs cartesian coordinate
I face a problem in comparing my CFD results (Fluent) with my LDA measures(Dantec) because they use cylindrical coordinate and cartesian coordinate respectively. Can I change the Fluent from a cylindrical coordinate to a cartesian coordinate?
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Re: cylindrical coordinate vs cartesian coordinate
Hi, I dunno if it is what you are looking for but here is the linked between the cartesian and cylindrical coord. in fluent Z -> X r -> Y theta -> Z
You can certainly find more informations on the fluent user web site (online documentation). Cheers, thomas |
Hi, I'm solving a natural convection problem in Fluent 13, but I want to model a 3D symetric cylindrical shape in 2-d. I assume (r=x, z=y, theta=0).
How can I change my coordinate from Cartesian to cylindrical??? |
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change your problem from 2D to aisymmetric. That's it. Best Wishes, Mukesh |
cylinderical coordinate in Fluent
I have done it. Draw my half shape, and define the symmetry axis as "axis" in Boundary condition, and select 'Axisymmetry' in define-solver, but there is an error : "Divergence detected in AMG solver: x-momentum"
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for UNSTAEDY PROBLEM: reduce the size of time step |
I have reduced relaxation factor of momentum equation from 0.7 to 0.3, 0.4, 0.5, 0.6, ... but there is still that error.
I even close the momentum equation (Solution control-equation) but this time the error was " Divergence detected in AMG solver: temperature " ! |
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Else there is some problem with BC. BTW what is problem you are trying to solve. |
Can you post BCs please?
OJ |
I have a rectangle ( a cross section of cylinder) I wanna solve Natural convection (and then solidification) problem.
I have a temperature gradient in right and left wall (my rectangle is 40x100). and this UDF is my boundary condition in left and right wall... I solve it in cartesian coordinate, but in Cylindrical, I have problem. #include "udf.h" DEFINE_PROFILE(temperature_profile, thread, index) { real x[ND_ND]; /* this will hold the position vector */ real y; face_t f; begin_f_loop(f,thread) { F_CENTROID(x,f,thread); y = x[1]; F_PROFILE(f, thread, index) =((1000*y)/2)+1223; } end_f_loop(f,thread) } |
I solved this problem in Planer (2d space) without any problem.
I reduce the Under-relaxation factor for energy and momentum. I aslo try to solve it Transient. But there is still this error. for momentum equation: " Divergence detected in AMG solver: x-momentum " for ener |
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