# how to perform temperature gradient on a particle (Thermophoretic Force)

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

 March 22, 2011, 09:20 how to perform temperature gradient on a particle (Thermophoretic Force) #1 New Member   mu lin Join Date: Oct 2010 Posts: 8 Rep Power: 8 Sponsored Links hi, everyone. Now i model dpm in a turbulent flow with a significant thermophoretic force. And just like what user's guide of fluent has introduced in 22.2.1 Equations of Motion for Particles. thermophoretic force is proportional to temperature gradient. F_thermal force=f(dT/dx) While in a 2D model, there are 2 directions for temperature gradient acted on a particles (as UDF manual , C_T_G(c,t)[0] and C_T_G(c,t)[1]) My Questions: (1) How could i write a correction formulation for thermophretic force on a particle with these two temperature gradient vector? (2) Why there is only Fx for a particle in user's guide of fluent when thermophoretic force is formed? What about Fy and Fz(if 3D case)? (3) if any body had a UDF about thermophoretic force, please send me a copy.Thank you very much. My email:mulin0803@sina.com or wwtmwtd@hotmail.com

 March 22, 2011, 13:36 #2 Senior Member     Amir Join Date: May 2009 Location: Montreal, QC Posts: 739 Blog Entries: 1 Rep Power: 16 Hi, I don't think that you're right. in user manual F_x is just a notation and the force acts in resultant gradient vector direction. you can also check that in a simple case which has temperature gradient only in y-direction.

 March 22, 2011, 22:21 how to perform temperature gradient on a particle (Thermophoretic Force) #3 New Member   mu lin Join Date: Oct 2010 Posts: 8 Rep Power: 8 Maybe i know what you mean. What i have modeled is a cross flow. so for a tueb surface it is a circle, even in the flow field it is hardly to show what is the exact direction of thermophoresis. Well, if U have a better code ,please send me a copy, and i will still study and search some literatures on it. Thank you Amir.

 March 23, 2011, 03:10 #4 Senior Member     Amir Join Date: May 2009 Location: Montreal, QC Posts: 739 Blog Entries: 1 Rep Power: 16 I meant that you can generate a simple mesh(e.g. a cube) and perform a temperature gradient in y-direction with boundary conditions and see whether it influences the particles or not.

 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 Catherine FLUENT 1 August 24, 2012 09:10 Sandrine Main CFD Forum 2 June 10, 2009 16:34 Mikka Main CFD Forum 0 August 5, 2007 21:55 Mikka Main CFD Forum 0 June 30, 2007 22:16 phsieh2005 Main CFD Forum 8 March 28, 2007 07:12