# heat realease in wall by surface reaction (FLUENT)

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

 March 17, 2006, 16:32 heat realease in wall by surface reaction (FLUENT) #1 Marie-Anne Guest   Posts: n/a Hi, I am confused about which boundary conditions to choose for the wall where a surface reaction that releases heat takes place. If I choose constant temperature, then the fact that the wall should be heated is lost. If I choose zero heat flux, then it heats too much because it is considered as adiabatic. Thanks for any advice or previous experience on that. Marie-Anne

 March 17, 2006, 16:47 Re: heat realease in wall by surface reaction (FLU #2 Andrew Hayes Guest   Posts: n/a I believe that would be a constant heat flux bc, as long as your reaction is exothermic. You have to know the heating value of the reaction

 March 18, 2006, 00:36 Re: heat realease in wall by surface reaction (FLU #3 Marie Anne Guest   Posts: n/a Thanks Andrew but I believe that knowing the enthalpy of formation, fluent computes itself the heat produced by the reaction. I just dont know where this heat goes and how to tell Fluent it heats the wall. Thank you Marie Anne

 March 18, 2006, 06:59 Re: heat realease in wall by surface reaction (FLU #4 Andrew Mettler Hayes Guest   Posts: n/a when you set up the boundary condition for the wall you can set it up as a constant heat flux. you just have to know how much heat is being released. Though, I have never done any reaction stuff. When I do a constant heat flux in fluent I set up a surface in Gambit that I can define as a 'constant heat flux' in Fluent - sort of hard to explain via the net.

 March 20, 2006, 09:15 Re: heat realease in wall by surface reaction (FLU #5 RoM Guest   Posts: n/a Another option is to use the convection bc with a high htc (>1000). In this case the free stream temperature is almost equal to the outer wall temperature of your domain. This approach is good if you have already measured vaules for outer wall temperature. RoM