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?

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 2d. 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 definesolver, but there is an error : "Divergence detected in AMG solver: xmomentum"

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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 controlequation) 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 Underrelaxation 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: xmomentum " for ener 
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