Define particales in close chamber

mahde1818 · February 22, 2015, 02:59

i want to simulate closed chamber fill up with particles.how can i define it in cfx i dont want to inject them in certain time. i want to simulation start from from time that chamber is full of particles and air suck up how can i do that ?

ghorrocks · February 22, 2015, 05:25

What type of particles? What flowing do the particles do? What is the fluid? Is the fluid agitated? What is the geometry?

Please provide more information about what you are doing.

JuPa · February 22, 2015, 08:57

You might have issues if the particles are initially at rest.

Ansys support informed me CFX and Fluent cannot model saltation.

mahde1818 · February 22, 2015, 16:33

look at this pic it say everything about my project

ghorrocks · February 22, 2015, 18:18

As Mr CFD says CFX does not have models to support this sort of thing. You might be able to simplify it a little and use the maximum packing fraction stuff in the fluidised bed stuff, or you might be able to link CFX to a discrete element model (like EDEM) for the particle modelling to include the packing effects. Both of these approaches are not simple and are simplifications, so you will have to decide whether it is good enough in your case.

mahde1818 · February 22, 2015, 18:43

[QUOTE=ghorrocks;532928]As Mr CFD says CFX does not have models to support this sort of thing. You might be able to simplify it a little and use the maximum packing fraction stuff in the fluidised bed stuff, or you might be able to link CFX to a discrete element model (like EDEM) for the particle modelling to include the packing effects. Both of these approaches are not simple and are simplifications, so you will have to decide whether it is good enough in your case.[/QU
How can I link EDEM to cfx ? Is there any tutorial for it? I want to calculate deformation of memberian

ghorrocks · February 22, 2015, 18:48

Talk to the suppliers of EDEM for the software, how to link it to CFX and tutorials.

mahde1818 · February 23, 2015, 02:45

Quote:

Originally Posted by ghorrocks

As Mr CFD says CFX does not have models to support this sort of thing. You might be able to simplify it a little and use the maximum packing fraction stuff in the fluidised bed stuff, or you might be able to link CFX to a discrete element model (like EDEM) for the particle modelling to include the packing effects. Both of these approaches are not simple and are simplifications, so you will have to decide whether it is good enough in your case.

you said simplify what kind of simplification? i mean which part of problem eliminate with this simplification?

ghorrocks · February 23, 2015, 05:20

All simulations are simplifications - the Navier Stokes equations makes important assumptions you should be aware of (such as the assumption the fluid can be modelled as a continuum). So as soon as you choose to use CFX to conduct a simulation you are making simplifications.

Using the fluidised bed model obviously makes the assumption that the fluidised bed model is applicable. This model was developed to model fluidised bed combustors so you will have to be careful applying it to sand bed modelling. The discrete element model makes less bold assumptions, but still assumes that the sand can be modelled as point particles. So the flow through the sand bed will be an approximation.

February 22, 2015, 02:59	Define particales in close chamber	#1
mahde1818 New Member mehdi Join Date: Feb 2015 Posts: 9 Rep Power: 11	i want to simulate closed chamber fill up with particles.how can i define it in cfx i dont want to inject them in certain time. i want to simulation start from from time that chamber is full of particles and air suck up how can i do that ?

February 23, 2015, 05:20		#9
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,872 Rep Power: 144	All simulations are simplifications - the Navier Stokes equations makes important assumptions you should be aware of (such as the assumption the fluid can be modelled as a continuum). So as soon as you choose to use CFX to conduct a simulation you are making simplifications. Using the fluidised bed model obviously makes the assumption that the fluidised bed model is applicable. This model was developed to model fluidised bed combustors so you will have to be careful applying it to sand bed modelling. The discrete element model makes less bold assumptions, but still assumes that the sand can be modelled as point particles. So the flow through the sand bed will be an approximation. mahde1818 likes this.

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February 22, 2015, 05:25		#2
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,872 Rep Power: 144	What type of particles? What flowing do the particles do? What is the fluid? Is the fluid agitated? What is the geometry? Please provide more information about what you are doing.

February 22, 2015, 08:57		#3
JuPa Senior Member Mr CFD Join Date: Jun 2012 Location: Britain Posts: 361 Rep Power: 15	You might have issues if the particles are initially at rest. Ansys support informed me CFX and Fluent cannot model saltation.

February 22, 2015, 18:18		#5
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,872 Rep Power: 144	As Mr CFD says CFX does not have models to support this sort of thing. You might be able to simplify it a little and use the maximum packing fraction stuff in the fluidised bed stuff, or you might be able to link CFX to a discrete element model (like EDEM) for the particle modelling to include the packing effects. Both of these approaches are not simple and are simplifications, so you will have to decide whether it is good enough in your case.

February 22, 2015, 18:43		#6
mahde1818 New Member mehdi Join Date: Feb 2015 Posts: 9 Rep Power: 11	[QUOTE=ghorrocks;532928]As Mr CFD says CFX does not have models to support this sort of thing. You might be able to simplify it a little and use the maximum packing fraction stuff in the fluidised bed stuff, or you might be able to link CFX to a discrete element model (like EDEM) for the particle modelling to include the packing effects. Both of these approaches are not simple and are simplifications, so you will have to decide whether it is good enough in your case.[/QU How can I link EDEM to cfx ? Is there any tutorial for it? I want to calculate deformation of memberian

February 22, 2015, 18:48		#7
ghorrocks Super Moderator Glenn Horrocks Join Date: Mar 2009 Location: Sydney, Australia Posts: 17,872 Rep Power: 144	Talk to the suppliers of EDEM for the software, how to link it to CFX and tutorials.