Axial impeller modelling in CFX

famarcfd · June 13, 2011, 05:51

Hi all,
i am performing the development of a new impeller for an axial flow fan and, in doing this, i am using CFX as solver.
According to my informations, CFX is better than FLUENT in modelling turbomachinery applications, but i would like to know if there are some particular numerical settings/options for obtaining a better (more realistic) CFD results.

Anyone can help me?

Thanks in advance!

ghorrocks · June 13, 2011, 08:08

You mean is there a hidden button titled "generate accurate results"? No, I have not found that button yet. I will let you know if I find it.

To get accurate results you need good inputs (ie know what you are simulating), set it up correctly (ie experience in CFD) and know what outputs you are looking for. There are entire textbooks written to answer your question. Time to go to the library I think.

famarcfd · June 13, 2011, 09:15

Your answer does not correspond to the meaning of my question.
I know the physical phenomena typical of my application and i am aware of the aspects related to CFD in general.
I would like only get some information or tips helpful for making a better design exploration. Maybe there are some physical or numerical aspects that, at this moment, i have neglected: so, opinions of the community could help me in reconstructing the real physical phenomena of the flow field of an axial flow impeller.
This was (and is) the meaning of my question!

ghorrocks · June 13, 2011, 20:15

A general question gets a general answer. A good guide for general tips on getting accurate simulations with CFX is in the documentation, especially the best practises guides and "Tips for obtaining convergence".

famarcfd · June 14, 2011, 12:52

I have already read the documentation that you have cited and i also studied the chapter on turbomachinery modelling....some other tip?! For example, by experience deriving from modeling axial impeller.
This is what i am looking for.

ghorrocks · June 14, 2011, 19:45

If you have read the best practises guide and general doco then the next place to look is the literature to see what techniques other people use who are modelling similar things.

June 13, 2011, 05:51	Axial impeller modelling in CFX	#1
famarcfd New Member Join Date: Oct 2009 Posts: 22 Rep Power: 17	Hi all, i am performing the development of a new impeller for an axial flow fan and, in doing this, i am using CFX as solver. According to my informations, CFX is better than FLUENT in modelling turbomachinery applications, but i would like to know if there are some particular numerical settings/options for obtaining a better (more realistic) CFD results. Anyone can help me? Thanks in advance!

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June 13, 2011, 08:08		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	You mean is there a hidden button titled "generate accurate results"? No, I have not found that button yet. I will let you know if I find it. To get accurate results you need good inputs (ie know what you are simulating), set it up correctly (ie experience in CFD) and know what outputs you are looking for. There are entire textbooks written to answer your question. Time to go to the library I think.

June 13, 2011, 09:15		#3
famarcfd New Member Join Date: Oct 2009 Posts: 22 Rep Power: 17	Your answer does not correspond to the meaning of my question. I know the physical phenomena typical of my application and i am aware of the aspects related to CFD in general. I would like only get some information or tips helpful for making a better design exploration. Maybe there are some physical or numerical aspects that, at this moment, i have neglected: so, opinions of the community could help me in reconstructing the real physical phenomena of the flow field of an axial flow impeller. This was (and is) the meaning of my question!

June 13, 2011, 20:15		#4
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	A general question gets a general answer. A good guide for general tips on getting accurate simulations with CFX is in the documentation, especially the best practises guides and "Tips for obtaining convergence".

June 14, 2011, 12:52		#5
famarcfd New Member Join Date: Oct 2009 Posts: 22 Rep Power: 17	I have already read the documentation that you have cited and i also studied the chapter on turbomachinery modelling....some other tip?! For example, by experience deriving from modeling axial impeller. This is what i am looking for.

June 14, 2011, 19:45		#6
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,871 Rep Power: 144	If you have read the best practises guide and general doco then the next place to look is the literature to see what techniques other people use who are modelling similar things.