Restitution coefficient wall

naor · November 29, 2011, 12:47

hello how i specify Restitution coefficient wall ??
thanks

NAD · November 29, 2011, 23:42

hi. if you working on multiphase flow using Eulerian model you proceed like this:

define -> phases, select secondary phase, set and set Granular Temperature Model to Partial Differential Equation

now you can set coefficient of restitution under Boundary Conditions, wall (for second phase) under multiphase.

(source:http://www.cfd-online.com/Forums/flu...ase-model.html)

naor · November 30, 2011, 14:18

thank u!!!!
but now how can i define the granular temp?

NAD · December 1, 2011, 19:36

hi. do you mean the value of granular temperature?
you can take the default value 0.0001 .

naor · December 2, 2011, 02:07

yea, but i have a value and i dont see were to put it...

NAD · December 2, 2011, 04:29

hi.
like this : boundary condition -->inlet-->secondary phase--> momentum
you find granular temperature=0.0001
boundary condition -->outlet-->secondary phase-->multiphase
you find back flow granular temperature=0.0001
i hope this will help you.

naor · December 2, 2011, 08:11

i will try and let u know

thank u for the help and quick answers.

naor · December 18, 2011, 11:54

ok i tried it, but it strange i still cant se the difference.
i use an Eulerian model, and when i try to increased the volume fraction (B.C->velocity inlet-> volume fraction)

to 0.02, and make the initialized i get the next massage (before the running of the calc):
"turbulent viscosity limited to viscosity ratio of 1.00 e+5 in 27915 cells"

what it mean? do E model have a limit of volume fraction?

November 29, 2011, 12:47	Restitution coefficient wall	#1
naor New Member naor Join Date: Oct 2010 Posts: 18 Rep Power: 15	hello how i specify Restitution coefficient wall ?? thanks

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November 29, 2011, 23:42		#2
NAD Member Join Date: Oct 2011 Posts: 37 Rep Power: 14	hi. if you working on multiphase flow using Eulerian model you proceed like this: define -> phases, select secondary phase, set and set Granular Temperature Model to Partial Differential Equation now you can set coefficient of restitution under Boundary Conditions, wall (for second phase) under multiphase. (source:http://www.cfd-online.com/Forums/flu...ase-model.html)

November 30, 2011, 14:18		#3
naor New Member naor Join Date: Oct 2010 Posts: 18 Rep Power: 15	thank u!!!! but now how can i define the granular temp?

December 1, 2011, 19:36		#4
NAD Member Join Date: Oct 2011 Posts: 37 Rep Power: 14	hi. do you mean the value of granular temperature? you can take the default value 0.0001 .

December 2, 2011, 02:07		#5
naor New Member naor Join Date: Oct 2010 Posts: 18 Rep Power: 15	yea, but i have a value and i dont see were to put it...

December 2, 2011, 04:29		#6
NAD Member Join Date: Oct 2011 Posts: 37 Rep Power: 14	hi. like this : boundary condition -->inlet-->secondary phase--> momentum you find granular temperature=0.0001 boundary condition -->outlet-->secondary phase-->multiphase you find back flow granular temperature=0.0001 i hope this will help you.

December 2, 2011, 08:11		#7
naor New Member naor Join Date: Oct 2010 Posts: 18 Rep Power: 15	i will try and let u know thank u for the help and quick answers.

December 18, 2011, 11:54		#8
naor New Member naor Join Date: Oct 2010 Posts: 18 Rep Power: 15	ok i tried it, but it strange i still cant se the difference. i use an Eulerian model, and when i try to increased the volume fraction (B.C->velocity inlet-> volume fraction) to 0.02, and make the initialized i get the next massage (before the running of the calc): "turbulent viscosity limited to viscosity ratio of 1.00 e+5 in 27915 cells" what it mean? do E model have a limit of volume fraction?