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-   -   DPM (https://www.cfd-online.com/Forums/fluent/38918-dpm.html)

yooceframandi December 13, 2005 01:51

DPM
 
dear friends! how can i define wet particles?it means solid+solvent. I think i should define a droplet. and how can i define a new mixture material? i use fluent to simulate a continuous fluidized bed dryer.(2 input, 2 output) regards

HS December 13, 2005 06:34

Re: DPM
 
For a transient simulation, I suggest you write DPM property and switching and/or law UDFs to account for the fact that you have 2 substances in the droplet. Use a user-defined scalar to monitor the mass fraction of the solvent and then let the droplet properties be decided from the value of this scalar, for example.

/Henrik

yooceframandi December 13, 2005 07:23

Re: DPM
 
Dear Henrik! Thanks for reply, Henrik, i can't use UDF and UDS because i dont know that and i have not enough time (I'm MS student of chemical eng. and it is my final project). I mean how can i do that with fluent without UDF. Fluent have a mixture that contain 1 solid+ 3 species(silicon+ h2+ sih2,...) is it possible to change it's property to set that as my mixture? Henrik, i really need your help, help me please. best regards

HS December 13, 2005 08:16

Re: DPM
 
Hello again! Actually I'm also a MS student in Chemical Engineering doing my final project. :) Anyway I saw no other way than to learn how to write the UDFs I needed. I had not programmed in C before but in other languages and it was not very difficult, the UDF manual is not very large but it has some good examples. I suggest you start out looking at DEFINE_DPM_PROPERTY, DEFINE_DPM_SWITCH and DEFINE_DPM_LAW and maybe also DEFINE_DPM_BC. Good luck!

/Henrik

yooceframandi December 13, 2005 08:30

Re: DPM
 
hello Henrik! what is ur project? is it fluidized bed dryer? may i define a flow of wet particles at inlet?or i have to use injection? regards

Allan Walsh December 13, 2005 11:49

Re: DPM
 
Have you looked at wet combusting particles. Liquid fraction can be set as any material. Be careful on defining liquid fraction - volumetric or wet basis.

For a dryer, the basic version of Fluent should be okay. For combustion, problems can be encountered at boundaries.

yooceframandi December 18, 2005 08:45

Re: DPM
 
Dear Allan, Thanks for reply. i have 2 input( wet solids & fluidizing gas) and 2 output( dry solids & outlet gas).what is the best BC's? is it possible not to define injection and use mass-flow-inlet for inlet wet particles? regards


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