# Settling Velocity - FLUENT Discrete Phase Model

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

 March 2, 2002, 10:08 Settling Velocity - FLUENT Discrete Phase Model #1 Lily Guest   Posts: n/a I am trying to simulate, using FLUENT 5.4's Discrete Phase Model, the terminal settling velocity of a single spherical particle. The fluid velocity is zero in all direction. I then compare the terminal settling velocity to that calculated using Stoke's equation : i.e. v_t = (rho_p - rho_f)*g*D_p^2 /(18*mu) The simulated terminal settling velocity matches the velocity calculated from Stoke's equation for small particles (less or equal than 10 micron), but diverges when the particle size is larger than 100 micron. For example, the terminal settling velocity for a 2600 kg/m3, 100 micron diameter particle is -1.535e-01 m/s (from FLUENT) and -8.69e-03 m/s (from Stokes' equation). I have tried using smaller time step, but to no avail. Am I missing something blantantly obvious ? Any advice /suggestion are most welcomed. Many thanks in advance.

 March 2, 2002, 10:36 Error #2 Lily Guest   Posts: n/a Sorry "100 micron diameter particle is -1.535e-01 m/s (from FLUENT) and -8.69e-03 m/s (from Stokes' equation)" should have read "100 micron diameter particle is -8.08e-03 m/s (from FLUENT) and -8.69e-03 m/s (from Stokes' equation)"

 March 6, 2002, 22:44 Re: Settling Velocity - FLUENT Discrete Phase Mode #3 blue Guest   Posts: n/a Is what you said meaning that a particle is moving in static flow field and the particle move depending on its gravity? If yes, maybe, the reason is the stoke's equation cann't use again when the particle diameter is large.

 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 vittal FLUENT 4 October 28, 2014 11:07 venu FLUENT 4 December 28, 2011 07:52 pengsh CFX 2 July 12, 2001 02:43 Staffan FLUENT 2 October 18, 2000 10:20 ursenbacher Main CFD Forum 0 January 5, 1999 12:25

All times are GMT -4. The time now is 05:51.