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-   -   Non-spherical, inert particle tracking in FLUENT (https://www.cfd-online.com/Forums/fluent/44864-non-spherical-inert-particle-tracking-fluent.html)

Amanda May 30, 2007 10:21

Non-spherical, inert particle tracking in FLUENT
 
Hi!

I'm currently working on injection of inert particles into a combustion chamber. If the particle involved is non-spherical, how can I define the shape? I can only see 'diameter' when I set the injection in FLUENT. Please help!! Thanks!


margaret mkhosi May 30, 2007 11:26

Re: Non-spherical, inert particle tracking in FLUE
 
Hi, FLuent has an option for nospherical particles under the drag law, but you will have to specify the 'shape factor.

Amanda May 30, 2007 12:24

Re: Non-spherical, inert particle tracking in FLUE
 
Hi,

something that I'm curious about --> let's say I'm considering a long cylidrical shape (length is relatively long compare with its diameter), when I specify the 'shape factor' under the drag law, will the rotational motion of that cylinder being considered properly?

Thanks!!

Henrik May 31, 2007 06:22

Re: Non-spherical, inert particle tracking in FLUE
 
Hi!

The shape factor is the ratio of the surface area of a sphere having the same volume as your particle to the actual surface area of your particle. It is used by Fluent when determining CD for use with the drag force. As it does not include any information on exactly how your particle differs in shape from a sphere, it will not be possible for Fluent to correctly considered any rotational motion of your particle. If this is important for your simulations, maybe it will be easier to use a custom drag law that you may implement via a UDF.

Hope this helps!

/Henrik


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