DPM Parcel Number Problem

February 25, 2004, 22:17

Hi all,

I am currently using a DPM model to simulate particles within a bubble column.

My problem is with the DPM injection, despite changing factors like size, mass flow, and time step, Fluent always seem to inject 272 parcels per time step (even if the no. of particles per parcel is less than 1).

I haven't bee able to change it. How is this done, what am I missing!!

Thanks in advance Shane

viva · May 19, 2011, 23:40

Hi, could you please help me with understanding the DPM parcel concept.
How do you find , how many particles are there in the parcel and can the user change the number of particles in one parcel.

Thanks in advance

alighaffari · May 20, 2011, 02:13

Hi shane
what is your injection type?
I guess it is surface injection type. If you create a surface injection, a particle stream will be released from each facet of the surface and so it only depends on your number of mesh in that surface. I think it will be better to use group injection type therefore you can control number of injection streams. For more information see chapter22 of fluent 6.3 users guide.

Amir · May 20, 2011, 03:05

Hi Ali,
It doesn't need to define group injection for this purpose. it's better to create virtual surfaces with sample points.

viva · May 20, 2011, 12:52

Hi Amir:

Could you please elaborate a little on how to create virtual surfaces and how to create sample points? Is there any reference that can help me to understand this?

Thanks for your help.

Amir · May 20, 2011, 13:00

Quote:

Originally Posted by viva

Hi Amir:

Could you please elaborate a little on how to create virtual surfaces and how to create sample points? Is there any reference that can help me to understand this?

Thanks for your help.

Hi,
surface->plane ; toggle on bounded and sample points & set sample density
set this surface in injection panel. you have particles in each sample point instead of boundary faces.

viva · May 20, 2011, 14:44

Thanks Amir.

morihangi · October 25, 2012, 09:24

Hi
I still don't understand how to change the number of particles in a parcel!!
would you describe a little more
thanks,

February 25, 2004, 22:17	DPM Parcel Number Problem	#1
Shane Guest Posts: n/a	Hi all, I am currently using a DPM model to simulate particles within a bubble column. My problem is with the DPM injection, despite changing factors like size, mass flow, and time step, Fluent always seem to inject 272 parcels per time step (even if the no. of particles per parcel is less than 1). I haven't bee able to change it. How is this done, what am I missing!! Thanks in advance Shane

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May 19, 2011, 23:40		#2
viva New Member viva Join Date: Jan 2011 Posts: 14 Rep Power: 15	Hi, could you please help me with understanding the DPM parcel concept. How do you find , how many particles are there in the parcel and can the user change the number of particles in one parcel. Thanks in advance

May 20, 2011, 02:13		#3
alighaffari Member alighaffari Join Date: May 2011 Posts: 31 Rep Power: 15	Hi shane what is your injection type? I guess it is surface injection type. If you create a surface injection, a particle stream will be released from each facet of the surface and so it only depends on your number of mesh in that surface. I think it will be better to use group injection type therefore you can control number of injection streams. For more information see chapter22 of fluent 6.3 users guide.

May 20, 2011, 03:05		#4
Amir Senior Member Amir Join Date: May 2009 Location: Montreal, QC Posts: 735 Blog Entries: 1 Rep Power: 23	Hi Ali, It doesn't need to define group injection for this purpose. it's better to create virtual surfaces with sample points.

May 20, 2011, 12:52		#5
viva New Member viva Join Date: Jan 2011 Posts: 14 Rep Power: 15	Hi Amir: Could you please elaborate a little on how to create virtual surfaces and how to create sample points? Is there any reference that can help me to understand this? Thanks for your help.

May 20, 2011, 14:44		#7
viva New Member viva Join Date: Jan 2011 Posts: 14 Rep Power: 15	Thanks Amir.

October 25, 2012, 09:24		#8
morihangi New Member Mori Join Date: Oct 2012 Posts: 9 Rep Power: 14	Hi I still don't understand how to change the number of particles in a parcel!! would you describe a little more thanks,