# DPM problems

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

 January 23, 2013, 08:17 DPM problems #1 New Member   Join Date: Jan 2013 Posts: 1 Rep Power: 0 Hi all! i'm new in using fluent and i need a big help about modelling a dpm simulation. I run an unsteady 3D simulation where water droplets are being injected into turbulent airflow (std k-e model) with an uncoupled approch. so i run the continuous before and i injected the particles in a second step. i used a surface injection and i specified velocity and mass flow rate of every single point of injection of that surface and diameter and density of the particles. But: problem1: when the particles are injected there is a change of the residuals that let me think that the continuous is affected by the droplets. what can i do to set up in a right way an uncoupled simulation? problem2: i specified density and diameter of the particles and mass flow rate of each point of injection. but at each time step fluent injects a particle for each point of injection (about 51000) so i have a very big number of particles injected. This fact let me think that dansity or diameter setting weren't respected. maybe i have to change the type of injection. is there an injection in which u can set up a total mass flow rate of the whole area? many thanks!!

 January 29, 2013, 11:27 #2 New Member   Matty Join Date: Nov 2011 Posts: 5 Rep Power: 8 If you have ticked the 'interaction with continuous phase' this will be a coupled calculation. This wasnt clear to me at first either. You can run a DPM simulation without this option ticked, just have a suitable injection. As for your second problem, i have a similar issue. When using a surface injection + uncoupled, the mass flow rate is ignored. If you want a particular flow rate (kg/s) you must adjust your time step so that the number of particles injected per second is equivalent to what you want.

 Tags dpm, mass, mass flow rate, uncoupled approch

 Thread Tools Display Modes Linear Mode

 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 OffTrackbacks are On Pingbacks are On Refbacks are On Forum Rules

 Similar Threads Thread Thread Starter Forum Replies Last Post Mechstud Main CFD Forum 4 July 26, 2011 12:13 Prashanth FLUENT 3 April 3, 2009 17:45 Nikhil Dani FLUENT 0 January 1, 2009 12:58 joshkemp FLUENT 0 May 1, 2007 17:20 Micha Siemens 0 August 6, 2003 13:55

All times are GMT -4. The time now is 17:24.