-------- Forwarded Message -------- > From: Damm, Edward F. (E. Buddy) <[EMAIL PROTECTED]> > To: Damm, Edward F. (E. Buddy) <[EMAIL PROTECTED]> > Subject: FW: Convection solutions > Date: Thu, 27 Apr 2006 15:34:16 -0400 > > > -----Original Message----- > From: [email protected] [mailto:[EMAIL PROTECTED] On Behalf Of Jonathan Guyer > Sent: Thursday, April 27, 2006 2:14 PM > To: Multiple recipients of list > Subject: Re: Convection solutions > > > > On Apr 27, 2006, at 1:34 PM, Damm, Edward F. (E. Buddy) wrote: > > > Sorry, Hope the attached clarifies it. The second to the last > > equation is what I am talking about. The stuff before leads up to it. > > > The term that is not in the original reference, but that I added per > > our discussion was the 1/uc. > > It's not that you divide by uc; it's that you must factor it out of the > term to determine the coefficient. You have correctly identified your > convection term as > > \begin{equation} > \nabla\cdot \left[ M_{c}\cdot u_{c}y_{va}\cdot \frac{\partial > ^{2}G_{m}}{\partial u_{c}\partial \phi }\nabla \phi \right] > \end{equation} > > A convection \nabla\cdot\left[ u_c \vec{v} \right] represents the field > $u_c$ being transported by a velocity field $\vec{v}$. For FiPy's > purposes, the coefficient of the convection term is the velocity field > which, in your expression, is everything *but* $u_c$. > It's not that you need to explicitly divide by $u_c$; you simply need to > factor it out. > > Your convection *coefficient* (not equation!!!) is then: > > Mc * yva * d2Gmducdphi * phi.getFaceGrad() should this be (in my case of factoring out uc) >>> convTerm = (1/uc)*Mc * yva * d2Gmducdphi # added the (1/uc) >>> phaseVelocity = convTerm * phase.getFaceGrad() >>> c_convectionTerm = PowerLawConvectionTerm(coeff = phaseVelocity, diffusionTerm = c_diffusionTerm) > > > However you determine Mc, yva, and d2Gmducdphi, remember that they must > be determined on faces to be consistent with phi.getFaceGrad(). > -- E. Buddy Damm ph. 330-471-2703 [EMAIL PROTECTED]
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