CFD Online Logo CFD Online URL
www.cfd-online.com
[Sponsors]
Home > Forums > General Forums > Main CFD Forum

Ideas about Gas - Solid Cyclone Separator Simulations

Register Blogs Members List Search Today's Posts Mark Forums Read

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   January 11, 2016, 10:46
Default Ideas about Gas - Solid Cyclone Separator Simulations
  #1
New Member
 
uk
Join Date: Jul 2012
Posts: 16
Rep Power: 11
ardismo is on a distinguished road
Hi;

Im trying to simulate gas-solid cyclone separator used in cement industry. I will mention about boundary conditions and operating conditions. I need some ideas to solve more accurate , quicker solution with same accuracy or to correct my mistakes. These will helpful for me and for others who has need help on this subject.

operating conditions ;

- It is a multilevel system consists of 5 cyclone levels.
- very high dust loading particle.( 0.2 kg particle/ m^3 air)
- 12 to 20 m/s inlet velocity
- nearly 700 m^3 control volume

Boundary Conditions;

1 - velocity inlet
2 - pressure outlet or outflow

****normally outlet is not open to atmosphere. Gas always goes to upper cyclone level. So there must not be reverse flow.

3 - wall ,of cyclone body
4 - wall of dust outlet

Setup settings;

1 - Mesh count : 160K , 700K , 3M, 8M , 30M
2 - Eularian multiphase model with dense DPM option.
3 - Reynols stress model with linear pressure strain option
4 - pressure-velocity coupling scheme;
----Simple : there is no need to set a CFL but long computational time.
----Coupled : I have enough memory. But in Fluent theory manual, it says below 10 is not recommended for Courant number. And if you can't choose wright CFL in coupled , solution monitors fluctuates a lot.
5 - Spatial Discretization ;
---- Gradient :Green Gauss node based
---- Pressure : Presto
---- others : second or third order upwind---- solution monitors fluctuates a lot. So it says you to switch time-dependent simulation.
6 - Under Relaxation Factors : 0.5 for all parameters
7 - Initialization : Normal + FMG with 7 levels


QUESTIONS

1 - I will use Multi-Objective algorithm to get functions of separation efficiency and pressure loss depending on geometric and flow parameters. I could not get efficiency directly . I use 17 injections for 17 different diameters, I need efficiency for all diameters like output parameters.

2 - Is it necessary to set a boundary layer mesh while using RSM ?

3 - Which model would be more suitable for particle drag force calculations ?

Thank you in advance
ardismo is offline   Reply With Quote

Reply

Tags
cyclone, dpm, rsm, turbulence

Thread Tools Search this Thread
Search this Thread:

Advanced Search
Display Modes

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
Problem in setting Boundary Condition Madhatter92 CFX 12 January 12, 2016 04:39
Setting the height of the stream in the free channel kevinmccartin CFX 10 July 9, 2015 21:36
Gas Cyclone convergence problem lxlylzl FLUENT 36 July 21, 2012 02:31
Yplus [y+] value for gas solid two phase flow P.R.Naren Main CFD Forum 0 September 5, 2006 02:04
Gas pressure question Dan Moskal Main CFD Forum 0 October 24, 2002 22:02


All times are GMT -4. The time now is 23:22.