User defined functions

abhishek.iiest · May 15, 2015, 18:52

can anyone please tell me as to how i should write a user defined function for a horizontal magnetic field. i need to know all the macros required and the format in which it is to be written. also i need to know the governing equation that should be programmed into the udf and the way in which it is to be programmed.

pakk · May 18, 2015, 06:16

If you want an explanation on how to write UDFs and what macro's there are available, you should start with the Fluent manual.
Right now your question is too general to be answered...

abhishek.iiest · May 18, 2015, 06:39

actually i am dealing with a magnetohydrodynamic flow within a closed lid-driven cavity.in order to incorporate the magnetic field i am writing a udf. a lorentz force will be generated in the y-momentum equation.also a buoyancy term appears in the dimensional y-momentum equation.so my question is should i write a udf which includes both the magnetic field and the buoyancy term or write two separate udfs or whether i should write the udf only for the magnetic field term??

pakk · May 18, 2015, 06:44

That is a concrete question that somebody here might be able to answer.

I can not really do that with confidence... But I thought that buoyancy is automatically included in the Fluent calculations if you add gravity, so in that case you would only need to add the magnetic force. I am not sure of that, as I have never did a simulation where buoyancy is important. But your answer might still be in the manual.

abhishek.iiest · May 22, 2015, 10:15

i have another question. i want to know as how to include a hollow cylinder in a two dimensional cavity in ansys fluent.i have done everything i know but after completing meshing when i enter the set-up and open the tab for the boundary conditions then all the sides of the cavity that i have named previously in the meshing section does not appear in the boundary conditions tab.only the interior surface body and wall surface body appears in the tab.

May 15, 2015, 18:52	User defined functions	#1
abhishek.iiest New Member abhishek chakrabarti Join Date: May 2015 Posts: 8 Rep Power: 11	can anyone please tell me as to how i should write a user defined function for a horizontal magnetic field. i need to know all the macros required and the format in which it is to be written. also i need to know the governing equation that should be programmed into the udf and the way in which it is to be programmed.

May 18, 2015, 06:39	udf	#3
abhishek.iiest New Member abhishek chakrabarti Join Date: May 2015 Posts: 8 Rep Power: 11	actually i am dealing with a magnetohydrodynamic flow within a closed lid-driven cavity.in order to incorporate the magnetic field i am writing a udf. a lorentz force will be generated in the y-momentum equation.also a buoyancy term appears in the dimensional y-momentum equation.so my question is should i write a udf which includes both the magnetic field and the buoyancy term or write two separate udfs or whether i should write the udf only for the magnetic field term??

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May 18, 2015, 06:16		#2
pakk Senior Member Join Date: Nov 2013 Posts: 1,965 Rep Power: 27	If you want an explanation on how to write UDFs and what macro's there are available, you should start with the Fluent manual. Right now your question is too general to be answered...

May 18, 2015, 06:44		#4
pakk Senior Member Join Date: Nov 2013 Posts: 1,965 Rep Power: 27	That is a concrete question that somebody here might be able to answer. I can not really do that with confidence... But I thought that buoyancy is automatically included in the Fluent calculations if you add gravity, so in that case you would only need to add the magnetic force. I am not sure of that, as I have never did a simulation where buoyancy is important. But your answer might still be in the manual.

May 22, 2015, 10:15		#5
abhishek.iiest New Member abhishek chakrabarti Join Date: May 2015 Posts: 8 Rep Power: 11	i have another question. i want to know as how to include a hollow cylinder in a two dimensional cavity in ansys fluent.i have done everything i know but after completing meshing when i enter the set-up and open the tab for the boundary conditions then all the sides of the cavity that i have named previously in the meshing section does not appear in the boundary conditions tab.only the interior surface body and wall surface body appears in the tab.