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 Dr C.Bhasker March 27, 2006 00:00

CFX + MHD

Can some body or CFX support team help in getting a sample tutorial case for solving MHD dealing with 2d/3d problem?

 Eugeny Pavlov March 27, 2006 02:15

Re: CFX + MHD

We create technology wich used Ansys Multiphysics and Ansys CFX for modelling transient MHD flow with high magnetic Reynold's number, i.e. with influence velocity on magnetic field.

Sorry for my bed english Russia, Syberia, Krasnoyarsk

 Dr C.Bhasker March 27, 2006 04:30

Re: CFX + MHD

Thanks for your quick response! please send us a example pdf/text file that can work in Ansys-CFX

Regards,

 opaque March 27, 2006 09:59

Re: CFX + MHD

If you contact your CFX help desk, they can provide you with the beta feature description to run MHD problems using ANSYS CFX-10.0.. There is even a sample GUI where you can setup the basics of the problem..

The beta feature allows to solve for the electric potential in the fluid and solid domains.. Includes also a quasi-steady version of the magnetic vector potential formulation. There is no need for User Fortran (as it used to be 5.5.x-> 5.7.1).. For low frequency electromagnetics, all is included within ANSYS CFX.

Good luck, Opaque

 Eugeny Pavlov March 28, 2006 02:34

Re: CFX + MHD

Dear Opaque I do not have information about the quasi-steady version of the magnetic vector potential formulation in CFX supported two-forked exchange (calculation) Force-Velocity between Navier and Maxwell equation. It is principial moment of correct magnetohydrodynamics. Your citation - "For low frequency electromagnetics, all is included within ANSYS CFX" Magnetohydrodynamics has one principial parameter - the magnetic Reynolds number, which increase with increase of frequancy (for periodic field). If Rem<1 can neglect influence of magnetic field of eddy currents in liquid on field which their call (not exchenge velocity to Maxvell). If Rem>10 exchange (calculation) velocity required. Between 1<Rem<10 the precision of modelling on your conscience. If your have information about exchange (calculation) Force-Velocity between Navier and Maxwell equation in CFX then let us know. Yours faithfully, Eugeny

 Eugeny Pavlov March 28, 2006 02:42

Re: CFX + MHD

Sorry, but this site do not supported long message :( 2 part...

Between 1<Rem<10 the precision of modelling on your conscience. If your have information about exchange (calculation) Force-Velocity between Navier and Maxwell equation in CFX then let us know.

Yours faithfully, Eugeny

 Eugeny Pavlov March 28, 2006 02:43

Re: CFX + MHD

Sorry, but this site do not supported long message :( 2 part... Between 1<Rem<10 the precision of modelling on your conscience. If your have information about exchange (calculation) Force-Velocity between Navier and Maxwell equation in CFX then let us know. Yours faithfully, Eugeny

 opaque March 28, 2006 10:08

Re: CFX + MHD

Dear Eugeny,

By quasi-steady version, I meant the transient terms of the Maxwell equations are neglected/dismissed even for transient simulations. Certain class of problems fall into this category, and it is a common approximation in the literature and as you pointed out is a function of the magnetic Reynolds number.

The model can be summarized into the use of potential formulations, specifically the electric potential-magnetic vector potential neglecting transient terms. For the electric potential, the equation ANSYS CFX solves is

div (J) = div (J_e + J_b) = div (elec_cond * grad (elec_pot)) + div (elec_cond * vel x mag_induct) = 0

and, for the magnetic vector potential components (assumes constant magnetic permeability with Coulomb gauge)

div ( mag_perm^-1 grad (mag_vec_pot_i)) = J_i

If you contact the CFX help desk, they will provide you with the package to reconfigure the ANSYS CFX solver to allow setting up the models, boundary conditions, and running the solver.

For more detailed modeling such as including neglected transient terms or time periodic type of problems, you are probably better off using a more advanced package as ANSYS Multiphysics.

Good luck, Opaque..

 amajburi August 23, 2011 01:51

Rrquest

I have the same problem that you had. If possible please send me a procedure or tuturial for MHD solve in Ansys.
Email: amajburi@yahoo.com

Thanks

 Ramnik July 30, 2012 02:56

Hello,

I have been trying to implement conducting wall boundary condition for the MHD module using the Electric Potential Method. It requires to specify a fixed current or voltage.

I am trying to simulate turbulent flow in a square pipe and have not been able to figure out a way to calculate the required potential/voltage at the boundary.

Please comment if you have any ideas.

Regards
Ramnik

 sainath.s@tdps.co.in July 30, 2012 03:11

There is one example in CFX tutorials "Heat transfer from a heating coil" It is a CHT problem using Electric Resistance heating. Check it out.

 bitak February 3, 2013 16:53

Hello.
May I have those tutorials? Thanks
ingckh84@yahoo.com

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