# User Subroutine ----- sorent

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

 November 24, 2008, 01:26 User Subroutine ----- sorent #1 conglin Guest   Posts: n/a In the head of soren subroutine, it says "This subroutine enables the user to specify a source term (per unit volume) for enthalpy in linearized form: Source = S1P-S2P*T, (W/m3)". Why the unit is "w/m3"? Shouldn't enthalpy be J/kg?What does "per unit volume" mean? Should I define enthalpy (H) as: H = f(T)/ VOLP ? VOLP-----volume of the cell (m3).

 November 24, 2008, 12:37 Re: User Subroutine ----- sorent #2 ab Guest   Posts: n/a w/m3 is rate energy is added per unit volume (in this case a unit volume is a cubic meter). A watt is just one joule per second... using joules would have no meaning in a steady state simulation, because time in infinite.

 November 24, 2008, 20:45 Re: User Subroutine ----- sorent #3 conglin Guest   Posts: n/a Thank you, ad. I very appreciate your answer. In the letter,it said"using joules would have no meaning in a steady state simulation,because time in infinite." Do you mean that the sorent subroutine must be sued in a transient simulation? "in this case a unit volume is a cubic meter", and "the case" mesns the example equation-----"Source = S1P-S2P*T" or all the expressions used in this subroutine? If answer is the latter, then should I difine the source as: Source = H/VOLP = (S1P-S2P*T)/VOLP ? H ----- enthalpy, VOLP ----- volume of the cell in my mold. Regards. conglin