multiphase granular flows; options for secondary phase

RockOn · January 14, 2013, 06:49

Hi,

I am working through a FLUENT tutorial where a impeller mixes a vessel with 1/3 sand and 2/3 water

@ moderator: I do not know if I am allowed to provide the ANSYS Tutorial here, otherwise please delete the link.

When specifying the secondary phase, there are different options to be specified. I really worked through the FLUENT user guide, the FLUENT theory guide and there mentioned papers.

Especially for

- the granular viscosity (kintetic part of the viscosity) --> "symlial-obrian" or "gidaspow"
- the granular bulk viscosity (resistance to diletation) --> "lun-et-al" or constant value

I do not understand the difference.

The according ANSYS user/theory guides just mention the options and related formulas. Also after reading through the related papers (Lun et al. & Symlial et al.) and hardly understanding their theories I can not figure out when/why to use which option for the two above mentioned parameters.

Can someone maybe explain me the differences of the options -- respectively in which to use in which cases -- for both parameters?

Thank you very much in advance.

kind regards
RockOn

RockOn · January 15, 2013, 07:59

Nobody out there who can help me?

January 14, 2013, 06:49	multiphase granular flows; options for secondary phase	#1
RockOn New Member Join Date: Jan 2013 Posts: 2 Rep Power: 0	Hi, I am working through a FLUENT tutorial where a impeller mixes a vessel with 1/3 sand and 2/3 water @ moderator: I do not know if I am allowed to provide the ANSYS Tutorial here, otherwise please delete the link. When specifying the secondary phase, there are different options to be specified. I really worked through the FLUENT user guide, the FLUENT theory guide and there mentioned papers. Especially for - the granular viscosity (kintetic part of the viscosity) --> "symlial-obrian" or "gidaspow" - the granular bulk viscosity (resistance to diletation) --> "lun-et-al" or constant value I do not understand the difference. The according ANSYS user/theory guides just mention the options and related formulas. Also after reading through the related papers (Lun et al. & Symlial et al.) and hardly understanding their theories I can not figure out when/why to use which option for the two above mentioned parameters. Can someone maybe explain me the differences of the options -- respectively in which to use in which cases -- for both parameters? Thank you very much in advance. kind regards RockOn

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January 15, 2013, 07:59		#2
RockOn New Member Join Date: Jan 2013 Posts: 2 Rep Power: 0	Nobody out there who can help me?