CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > Software User Forums > ANSYS > FLUENT > Fluent Multiphase

Max. Packing Limit & Volume Fraction in Circulating Fluidized Bed

Register Blogs Community New Posts Updated Threads Search

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   May 4, 2016, 12:21
Default Max. Packing Limit & Volume Fraction in Circulating Fluidized Bed
  #1
New Member
 
Bramantyo
Join Date: May 2016
Location: Java
Posts: 11
Rep Power: 10
brams is on a distinguished road
Hello there

I am currently trying to simulating circulating fluidized bed boiler with Eulerian-Eulerian multiphase method, in FLUENT 15.
I am using 4 phases in this simulation. 1 phase is air, and then the other 3 are sands with different diameter.

The details are given below:
-phase 1: air
-phase 2: sand, diameter 50 micro
-phase 3: sand, diameter 175 micro
-phase 4: sand, diameter 500 micro

So my questions:
1. What is the appropriate max packing limit value for each sand phase? I've read in the user guide that max packing limit value maybe higher than 0.63(default value) if there is more than 1 sand phase

2. In the Slip Velocity Specification Method in Mass-Flow Inlet Boundary for sand phase, there is an option: Volume Fraction. What is the meaning of this volume fraction option? Can we just input the mass flow rate differently for each of the sand phase without choosing the volume fraction option?

Any explanation will be really helpful!

Thanks
brams is offline   Reply With Quote

Old   May 16, 2016, 14:31
Exclamation fuidized bed
  #2
New Member
 
Join Date: May 2016
Posts: 9
Rep Power: 10
kantay is on a distinguished road
Hi Brams,

unfortunately I can not help you because I am a beginner in this kind of work, but I think you can help me if you don't mind .I am a student of 2nd year master, I'm working on fluent.16 software for the simulation of fluidization (without combustion or chemical reaction) this fluidized bed uses the olive pomace as particles and air as the fluidizing. I draw the geometry of the boiler and I did the mesh but I found a lot of trouble about modeling (in fluent models), I try to understand but really it's not easy), please if you don't mind help me with advice or paper that can help me to advance in my project. I tried with documentation of ansys but it is too detailed and
scattered.
thank you for any help
kantay is offline   Reply With Quote

Old   May 23, 2016, 19:07
Default
  #3
New Member
 
Jerry
Join Date: Aug 2014
Posts: 1
Rep Power: 0
yjl19920614 is on a distinguished road
Hi Brams,

I have the same doubt. I am trying to simulate bidisperse system by using eulerian model. While I found the total volume fraction of two solid phases can be very large.

The maximum packing limit for each solid phase is set to 0.6 while the total volume fraction can be as high as 0.85 in the result. I checked fluent theory guide manual and calculated the maximum packing limit for binary system. The packing limit calculated from those equations is around 0.73.

Hope someone can help.
yjl19920614 is offline   Reply With Quote

Reply

Tags
circulating fluidized bed, eulerian multiphase model, eulerian-eulerian model, max. packing limit, volume fraction.


Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are On
Refbacks are On


Similar Threads
Thread Thread Starter Forum Replies Last Post
y+ and u+ values with low-Re RANS turbulence models: utility + testcase florian_krause OpenFOAM 114 August 23, 2023 06:37
negative min.(alpha1) value interFoam Arjun Jayakumar OpenFOAM 11 December 21, 2019 11:59
mpirun interFoam very stable --> then blows up ghadab OpenFOAM Running, Solving & CFD 3 October 27, 2013 11:34
Force can not converge colopolo CFX 13 October 4, 2011 23:03
On the damBreak4phaseFine cases paean OpenFOAM Running, Solving & CFD 0 November 14, 2008 22:14


All times are GMT -4. The time now is 23:40.