Re: how to set up data transfer between two adjacent nonuniform meshs

2016-10-04 Thread Zhekai Deng 
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 
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
>
> ___
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> fipy@nist.gov
> http://www.ctcms.nist.gov/fipy
>   [ NIST internal ONLY: https://email.nist.gov/mailman/listinfo/fipy ]
>
>
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RE: how to set up data transfer between two adjacent nonuniform meshs

2016-10-04 Thread Campbell, Ian 
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
___
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