I see. Thanks for clarifying it ! I will implement this over the weekend and to see how it works out. Thank you.

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Best, Zhekai On Wed, Oct 12, 2016 at 8:15 AM, Campbell, Ian <i.campbel...@imperial.ac.uk> wrote: > Dear Zhekai, > > > > My October 11th post to this list affects my recommendation to you from > October 4th. You’ll probably be fine if you aren’t running your simulation > for long, but if you are running it for long periods, it will likely become > cripplingly slow. I've implemented the corrected version below for you, > which should not have a memory leak because of the method of updating the > boundary condition. > > > > I hope that helps. > > > > Best regards, > > > > - Ian > > > > phi_1_initial, phi_2_initial = 0.0, 0.0 > D1, D2 = 1.5, 1.75 > > dx_1 = [0.03806023, 0.10838638, 0.16221167, 0.19134172, 0.19134172, > 0.16221167, 0.10838638, 0.03806023] > dx_2 = [0.03806023, 0.10838638, 0.16221167, 0.19134172, 0.19134172, > 0.16221167, 0.10838638, 0.03806023] > > mesh_1 = Grid1D(dx=dx_1, Lx=1.0) > mesh_2 = Grid1D(dx=dx_2, Lx=1.0) > > phi_1 = CellVariable(mesh_1, value=phi_1_initial) > phi_2 = CellVariable(mesh_2, value=phi_2_initial) > > eq_1 = TransientTerm() == ExplicitDiffusionTerm(coeff=D1) > eq_2 = TransientTerm() == ExplicitDiffusionTerm(coeff=D2) > > phi_1.faceGrad.constrain(0.5, where=mesh_1.facesLeft) > phi_1.constrain(1.0, where=mesh_1.facesRight) > inlet_BC_value = Variable() > phi_2.faceGrad.constrain(inlet_BC_value, where=mesh_2.facesLeft) > phi_2.faceGrad.constrain(-0.5, where=mesh_2.facesRight) > > timeStepDuration = 0.9 * min(dx_1)**2 / (2 * max(D1, D2)) > steps = 100 > viewer = Viewer(vars=(phi_1, phi_2)) > > for step in range(steps): > eq_1.solve(var=phi_1, dt = timeStepDuration) > inlet_BC_value_new = phi_1.faceValue[mesh_2.faceCenters == 1.0] # > Acquire the data > inlet_BC_value.setValue(float(inlet_BC_value_new)) > # Apply that data on the 2nd mesh > eq_2.solve(var=phi_2, dt = timeStepDuration) > viewer.plot() > > > > > > *From:* fipy-boun...@nist.gov [mailto:fipy-boun...@nist.gov] *On Behalf > Of *Zhekai Deng > *Sent:* 05 October 2016 05:20 > *To:* fipy@nist.gov > *Subject:* Re: how to set up data transfer between two adjacent > nonuniform meshs > > > > Hi Ian, > > > > Thank you very much for the example and pointing out the additional > reference. Those are very useful informations. This approach seems > intuitive and easy to incorporate into the code. I will try to incorporate > it into my own code. Thanks again. > > > > Best, > > > > Zhekai > > > > On Tue, Oct 4, 2016 at 5:23 AM, Campbell, Ian <i.campbel...@imperial.ac.uk> > wrote: > > Hi Zhekai, > > > > There is. > > > > Try the following, where as you suggest, the interpolated value at the > right-most face of mesh_1 is used. That (outward flowing) flux value is > then copied to the inlet boundary condition (Neumann/flux) for mesh_2. A > diffusion equation with a different coefficient for your solution variable > phi is defined on the 2nd mesh – this should work if you change the > equation further. Both meshes are non-uniform and of unit length. > > > > I don’t know from your question what type or magnitude boundary conditions > you’re interested in on the other faces, but nonetheless, you can see in > the figures produced from the code below that the outlet flux on the > right-most face of mesh_1 is equal to the inlet flux on the left-most face > of mesh_2. There’s likely a cleaner way to do this, by updating the value > of the boundary condition for mesh_2 rather than re-defining it, but this > is a start. > > > > An additional reference for you, here is Dr. Guyer’s suitably-named Gist: > https://gist.github.com/guyer/bb199559c00f6047d466daa18554d83d > > > > Let us know if that works for you. > > > > Best, > > > > - Ian > > > > phi_1_initial, phi_2_initial = 0.0, 0.0 > > D1, D2 = 1.5, 1.75 > > inlet_BC_value_init = 2.0 > > > > dx_1 = [0.03806023, 0.10838638, 0.16221167, 0.19134172, 0.19134172, > 0.16221167, 0.10838638, 0.03806023] > > dx_2 = [0.03806023, 0.10838638, 0.16221167, 0.19134172, 0.19134172, > 0.16221167, 0.10838638, 0.03806023] > > > > mesh_1 = Grid1D(dx=dx_1, Lx=1.0) > > mesh_2 = Grid1D(dx=dx_2, Lx=1.0) > > > > phi_1 = CellVariable(mesh_1, value=phi_1_initial) > > phi_2 = CellVariable(mesh_2, value=phi_2_initial) > > > > eq_1 = TransientTerm() == ExplicitDiffusionTerm(coeff=D1) > > eq_2 = TransientTerm() == ExplicitDiffusionTerm(coeff=D2) > > > > # Boundary Conditions > > phi_1.faceGrad.constrain(0.5, where=mesh_1.facesLeft) > > phi_1.constrain(1.0, where=mesh_1.facesRight) > > phi_2.faceGrad.constrain(inlet_BC_value_init, where=mesh_2.facesLeft) > > phi_2.faceGrad.constrain(-0.5, where=mesh_2.facesRight) > > > > timeStepDuration = 0.9 * min(dx_1)**2 / (2 * max(D1, D2)) > > steps = 100 > > viewer = Viewer(vars=(phi_1, phi_2)) > > > > for step in range(steps): > > eq_1.solve(var=phi_1, dt = timeStepDuration) > > inlet_BC_value = phi_1.faceValue[mesh_2.faceCenters == 1.0] # > Acquire the data > > phi_2.faceGrad.constrain(inlet_BC_value, where=mesh_2.facesLeft) # > Apply that data on the 2nd mesh > > eq_2.solve(var=phi_2, dt = timeStepDuration) > > viewer.plot() > > > > *From:* fipy-boun...@nist.gov [mailto:fipy-boun...@nist.gov] *On Behalf > Of *Zhekai Deng > *Sent:* 04 October 2016 03:29 > *To:* fipy@nist.gov > *Subject:* how to set up data transfer between two adjacent nonuniform > meshs > > > > Hello All, > > > > I wonder is there any way to allow the data share on the two nonuniform > mesh's interface ? To explain this, let's say I have two meshes, mesh_1 and > mesh_2. Different equations govern the mesh_1 and mesh_2, and solution > variable on both meshes is phi. I would like the outlet (on the right > face) on mesh_1 served as inlet(on the left face) on mesh_2. > > > > I tired to concatenate two mesh. If they are uniform, this works fine. > However, if two does not share the exact the same face (for example, one is > uniform, and another is nonuniform), there seems to be problem. . > > > > Thus, I wonder is there any way to "interpolate" the phi.facevalue on > mesh_1 outlet face, and apply this interpolation value into the inlet of > mesh_2? > > > > > > Best, > > > > Zhekai > > > _______________________________________________ > fipy mailing list > fipy@nist.gov > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] > > > > _______________________________________________ > fipy mailing list > fipy@nist.gov > http://www.ctcms.nist.gov/fipy > [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ] > >

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