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

problem in particle injection in discrete phase modelling

Register Blogs Community New Posts Updated Threads Search

Like Tree1Likes
  • 1 Post By sajeesh

Reply
 
LinkBack Thread Tools Search this Thread Display Modes
Old   March 4, 2013, 06:58
Default problem in particle injection in discrete phase modelling
  #1
Member
 
sajeesh
Join Date: Feb 2013
Posts: 52
Rep Power: 13
sajeesh is on a distinguished road
hi
i am trying to simulate the transient particle tracking in a fluid flow through a square channel.i want to study the transient behavior of a single particle..how i can inject one partilce in to the flow stream...
Even i am managed to give group injection and when i am running the code it is showing particle deleted during some iterations..and also in plot particle tracking result option.no tracking of particle have been done...any body can help me
arjun425 likes this.
sajeesh is offline   Reply With Quote

Old   March 4, 2013, 12:27
Default
  #2
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,385
Blog Entries: 23
Rep Power: 29
diamondx will become famous soon enough
have you check unsteady ??? if yes look at your stop time in injection, it should be of a large value so injection never stops.
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/KAOIwm
Ali
diamondx is offline   Reply With Quote

Old   March 4, 2013, 12:43
Default
  #3
Member
 
sajeesh
Join Date: Feb 2013
Posts: 52
Rep Power: 13
sajeesh is on a distinguished road
thank you sir.


Sir i am doing unsteady..but sir in ansys user guide i saw if we put start time and stop time as zero..injection will be onlly in the starting of calculation...sir exactly i need one particle in the flow....


My problem defnition is
initially i have no particle so i apply mass flow rate as inlet condition and preesure as outlet boundary condition..after simulation i will get inlet pressure also...so the total preesure drop i can found out\
\
I need all the above things when a solid sphere is moving unsteadily in the fluid.the present condition is as follows.initially solid sphere is placed in the fluid.it is taken by the drag force acting on it.later this sphere will modify the flow as two way coupling..after that steady state reached...

sir in this model how i get one particle instead of one stream of particle


Sir i am not sure my approach is correct..pls g
sajeesh is offline   Reply With Quote

Old   March 4, 2013, 12:45
Default
  #4
Super Moderator
 
diamondx's Avatar
 
Ghazlani M. Ali
Join Date: May 2011
Location: Tokyo, Japan
Posts: 1,385
Blog Entries: 23
Rep Power: 29
diamondx will become famous soon enough
in your injection, how many particle are you giving ??
__________________
Regards,
New to ICEM CFD, try this document --> https://goo.gl/KAOIwm
Ali
diamondx is offline   Reply With Quote

Old   March 4, 2013, 13:01
Default
  #5
Member
 
sajeesh
Join Date: Feb 2013
Posts: 52
Rep Power: 13
sajeesh is on a distinguished road
i have no answer for that...i dont know to calculate that also....i given the inlet condition as single
x y and z velocity as zero
mass flow rate of particle a low value as 8e-14 kg/sec to make the particle as one per minute....

but during the calculation in console

'particle trapped one ' it is showing after some iteration' particle escaped one ' showing ...even we stop iteration before escping particle ..i search for the result as follows
the plot and animation
particle tracking

particle ID''

no result is showing as a result

now i have doubt in setiing the particle time step and fluid time step .....how i should set up that.i didnt understand these things from user guide
sajeesh is offline   Reply With Quote

Old   March 4, 2013, 15:30
Default
  #6
Senior Member
 
A CFD free user's Avatar
 
A-A Azarafza
Join Date: Jan 2013
Posts: 226
Rep Power: 14
A CFD free user is on a distinguished road
I had such problem before. I think you need to have a deep look at the fluent user guide concerning simulation setup and setting parameters model for step time, step size and etc. Maybe you better to start a steady state and after get enough experience change to unsteady. I don't know how I solved the problem now but I can recommend you that the key to solve the problem lies in step time and size.
A CFD free user is offline   Reply With Quote

Old   March 4, 2013, 21:52
Default
  #7
Member
 
sajeesh
Join Date: Feb 2013
Posts: 52
Rep Power: 13
sajeesh is on a distinguished road
i tried but its not working............you r right sir...the key area is the time step....actually how the iteration is done...iterating the fluid in a certain number.then injecting the particle ..the particle advancing time period how we can determined..when the DPM iteration is happening...i have no idea from the guide....pls help me sir...regarding the iteration procedure
thanks
sajeesh is offline   Reply With Quote

Old   March 5, 2013, 12:51
Default
  #8
Senior Member
 
A CFD free user's Avatar
 
A-A Azarafza
Join Date: Jan 2013
Posts: 226
Rep Power: 14
A CFD free user is on a distinguished road
You need to get a converged solution without DPM model, then inject the particles. There are several types of particle injecting. You can inject only one particle or a group of particles or other types described in user guide. You can even adjust Rosin-Ramler parametrs and use this method. Hope it help.
A CFD free user is offline   Reply With Quote

Old   March 5, 2013, 23:18
Default
  #9
Member
 
sajeesh
Join Date: Feb 2013
Posts: 52
Rep Power: 13
sajeesh is on a distinguished road
sir one more doubt..if i want one particle to track..how i put one particle in one stream..option single in injection means that single stream.that is not one particle.sir what value i should give to the mass flow rate for one particle.and initially i want to place the particle not with one velocity at the injection point.can i set a velocity of zero for a stationary particle at the inlet.

sorry sir if it is blunder

thank a lot for your reply
sajeesh is offline   Reply With Quote

Old   March 6, 2013, 12:34
Default
  #10
Senior Member
 
A CFD free user's Avatar
 
A-A Azarafza
Join Date: Jan 2013
Posts: 226
Rep Power: 14
A CFD free user is on a distinguished road
I think what you need is injecting massless particle. In this case you don't need to set velocity value or even mass flow rate. The only thing would be required is the position of the injected particle. Actually, in this method of injecting the particles move along the stream lines.
Good Luck
A CFD free user is offline   Reply With Quote

Old   March 6, 2013, 12:48
Default
  #11
Senior Member
 
A CFD free user's Avatar
 
A-A Azarafza
Join Date: Jan 2013
Posts: 226
Rep Power: 14
A CFD free user is on a distinguished road
Please If you have any questions, contact me as:
aboozar.azarafza@gmail.com
Cause, I may forget to see this page.
A CFD free user is offline   Reply With Quote

Reply


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
Diesel injection problem Jurek FLUENT 2 June 16, 2017 07:05
Thermal phase change set up problem Danial Q Main CFD Forum 1 July 10, 2014 15:41
Uncoupled calculation for discrete phase? ljp FLUENT 2 September 21, 2010 12:16
report discrete phase data problem. seasoul FLUENT 0 April 22, 2008 02:10
Discrete phase modellision through a free surface thomas Main CFD Forum 0 December 10, 2003 09:05


All times are GMT -4. The time now is 00:55.