# surface reaction

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

 August 19, 2003, 10:06 surface reaction #1 pepa Guest   Posts: n/a Does anybody do the simulation with the equilibrium raction on the surface? Please could you help me?

 August 19, 2003, 10:23 Re: surface reaction #2 andrew_garrard Guest   Posts: n/a Yes, I was doing this sort of simulation about six months ago. I was using fluent5 and there was the option to turn on the backward reaction in a surface reaction. However in fluent 6 the option seems to be removed, leading me to think that the option was probably not avaliable or very good in the earlier version. The easiest way aroud it is to create your own reaction sheme via a UDF. It isn't that difficult. it is improtant to know that the *rr varibale specifies the molar rate of production of your species rather than the equlibrium constant. If you need anymore help with this I can help you as much as I can.

 August 19, 2003, 11:57 Re: surface reaction #3 pepa Guest   Posts: n/a Okey, before I start with the UDF I would like to try something. Meybe I have stupid question, but which units of pre-exponencial factor does FLUENT use by the reaction type - wall surface. Or the reaction is in [kmol/m2-s]??? Is it right?

 August 20, 2003, 05:04 Re: surface reaction #4 andrew_garrard Guest   Posts: n/a The manual says that the units of pre-exponencial factor are consistent, but I do not know what this means. from equation 13.1-9 I can only assume the units are s-1 k-1. If you are specifying the surface reaction rate, as in define -> user -> function hooks surface reaction, then yes, kmol/m2-s looks like the right unit for that.

 August 20, 2003, 22:05 Re: surface reaction #5 Greg Perkins Guest   Posts: n/a Actually they should be determined by you depending upon for example the exponent of the temperature term and concentration term, such that the overall rate will come out to be in kmol/m3-s. I foudn this all a little confusing to begin with too, but it all makes sense. Consider some reactions with say 2nd order reactant dependencies and then figure out what the k term will be. You'll find it does depend on the exponents. Greg

 August 21, 2003, 00:14 Re: surface reaction #6 Greg Perkins Guest   Posts: n/a sorry in the above I was thinking about volume reactions, for surface reactions the rate should be in kmol/m2-s

 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 nishant_hull Open Source Meshers: Gmsh, Netgen, CGNS, ... 23 August 5, 2015 02:09 NewKid OpenFOAM 18 January 20, 2011 17:55 fkuwo FLUENT 0 August 14, 2009 11:04 Chie Min CFX 5 July 12, 2001 23:19 La S. Hyuck CFX 1 May 23, 2001 00:07

All times are GMT -4. The time now is 16:17.