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Solution dependent material coefficient? How to use specifyCoefficients in pdetool (for a time dependnet PDE solution)
Define a function or a anonymous function handle as per the prescribed format. For example you can define: cFcn = @(region,stat...

fast 4 Jahre vor | 0

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partial derivative coding in matlab
Although I have not looked into details, you might be able to setup this problem using pdepe function available in base MATLAB (...

fast 4 Jahre vor | 0

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Capacitance by solving Poisson equation
If you setup the problem using PDE Toolbox, look here for example, then you get the gradients of the solution in the results. ...

fast 4 Jahre vor | 0

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How to properly add radiative heat flux boundary conditions in a stationary heat transfer problem using the pde toolbox?
Hi Eduardo, The issue is with the default tolerance. The default tolerance of 1E-4 in the model is too loose for your problem. ...

fast 4 Jahre vor | 0

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How i can write transient condition in a pde thermal model?
Example: If you want to write y^2 - 2*t^2, you write: handlename=@(region,state) region.y.^2 - 2 * state.time^2 Yes, if it de...

fast 4 Jahre vor | 0

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How can I solve 2D transient diffusion equation with nonlinear source term?
I don't see any interaction between species being defined by the stated PDEs. You can define coefficients usng PDEModel workflo...

fast 4 Jahre vor | 0

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questions about the 'pdeeig'
Please use one the newer workflow like general equation based one, Structural or Thermal one. Once you setup your model in one ...

fast 4 Jahre vor | 0

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Haw can I use the PDE toolbox to model isotropic thermal expansion?
The latest version of MATLAB has the capabality to solve for thermal expansion and thermal stress by specifying temperature as a...

fast 4 Jahre vor | 0

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capability pde toolbox, 3d application heat transfer
If your 3-D model that you discretize involve only cubes then you can model this in PDE. For example see attached image: Yo...

fast 4 Jahre vor | 1

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Defining non-constant Neumann Boundary Conditon
You do not need to model the interface BC explicitly. This condition should be automatically satisfied in the solution. Regard...

fast 4 Jahre vor | 0

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PDE Toolbox - Convection in Diffusion Equation
It looks like your function errored without returning one onput. Most likely the error could have been due to 'va' being out of...

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How to integrate PDE solution in 2D space?
If you are solving a single PDE, i.e., you used createpde(1) then you need to specify time-steps as the last argument. If you ha...

fast 4 Jahre vor | 0

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How to set boundary conditions?
If you are using PDE Toolbox, then you have to create all those edges, and then you would be able to do it. Refer to the documen...

fast 4 Jahre vor | 0

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3D Multi-Domain PDE Modelling
Thanks for taking time to explain the problem with such a detail and for providing the reproduction code. I tried to understand ...

fast 4 Jahre vor | 2

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How to plot DiscreteGeometry objects
Looks like you are overwriting the plot in a loop. If you want to plot multiple figures then you insert: figure command before p...

fast 4 Jahre vor | 0

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Error While exporting data to workspace.
You can export solution by selecting menu option: Solve> Export Solution This would export the solution as 'u' variable to wor...

fast 4 Jahre vor | 0

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Use of "region" and "state" in PDE models with variable coefficients.
Hi Allen, Solver passes two input arguments to the function that you define, "region" and "state" are just place holder names....

fast 4 Jahre vor | 0

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Import a 2D STL File
Hi Matthias, Your geometry in the STL file is indeed 3-D. I am assuming you want just the one of the flat faces for two 2-D an...

fast 4 Jahre vor | 0

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Import a 2D STL File
The keyword here is "planar". Is your geomtry planar? Regards, Ravi

fast 4 Jahre vor | 0

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Thermal simulation with Nodal Temperature Initial Condition
Couple of options: You can use a function to define the temperature, which you can specify to thermalIC as function_handle. Y...

fast 4 Jahre vor | 0

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PDE toolbox and load on nodes
OK, in that case can you number the number of verteices in the model: >> gm Do you see the new VertexID in the plot you make? ...

fast 4 Jahre vor | 0

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PDE toolbox and load on nodes
The function addVertex was introduced in R2019b. You might be running an older version of the MATLAB to get this error. Regard...

etwa 4 Jahre vor | 0

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PDE Toolbox: Constant external heating on 4 sides of a Cylinder
Hi Pascal, If there is no axial variation, then I suggest using a 2-D crosssecion to solve the problem. In 2-D you can easily ...

etwa 4 Jahre vor | 0

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EvaluateHeatRate Matlab PDE units and discussion
evaluateHeatRate returns the value of heat flux integrated our the specified face. So its unit would be unit of enery, if everyt...

etwa 4 Jahre vor | 0

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How can I modify the default options (like RelTol' and 'AbsTol') of the pde solver when using the PDE toolbox?
You can edit those tolerances directly using the model object properties. Say, model = createpde(... User model the set RelTo...

etwa 4 Jahre vor | 0

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Question on using geometryFromMesh
It looks like the node IDs from COMSOL might be 0 based. That is first node ID in COMSOL may be 0, in MATLAB it must be 1. You c...

etwa 4 Jahre vor | 1

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Time dependent external heat flux in PDE Toolbox
Hi Pascal, You are on the right track, refer to the externalHeatFlux in the example: https://www.mathworks.com/help/pde/ug/h...

etwa 4 Jahre vor | 0

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Unexpected Result for 3-D Thermal Transient Analysis of Heat sink using PDE Solver Toolbox
Here is the correct results using the new STL after fixing two more inconsitencies: Radiation problem should include temperatu...

etwa 4 Jahre vor | 1

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Unexpected Result for 3-D Thermal Transient Analysis of Heat sink using PDE Solver Toolbox
Hello Jake, You seem to have unit mismatch in the MATLAB model. PDE Toolbox doesn't have any units. When you exported the geom...

etwa 4 Jahre vor | 1

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Solving 2D Convection Diffusion Equation
You might be able to setup the 2-D version using PDE toolbox. Take look at the following code. Please verify I have accuratly ca...

etwa 4 Jahre vor | 0

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