Answered

Adaptive mesh refinement function for time-dependent problems?

Adaptive refinement of time-dependent problem is not currently available in PDE Toolbox. However, you can do a coarse adaptive...

Adaptive mesh refinement function for time-dependent problems?

Adaptive refinement of time-dependent problem is not currently available in PDE Toolbox. However, you can do a coarse adaptive...

10 days ago | 0

| accepted

Answered

PDE Toolbox: evaluateGradient for legacy workflow or convert legacy solution to PDE solution

Hi Maxime, You can create a result object of the kind you need using the solution from the legacy solver and the createPDEResu...

PDE Toolbox: evaluateGradient for legacy workflow or convert legacy solution to PDE solution

Hi Maxime, You can create a result object of the kind you need using the solution from the legacy solver and the createPDEResu...

10 days ago | 1

| accepted

Answered

How can I just get the corner points in the 3D model?(PDE Toolbox)

Hi Haoran, It looks like you are interested in nodes that form the triangle element corners and not the midside nodes. Two opt...

How can I just get the corner points in the 3D model?(PDE Toolbox)

Hi Haoran, It looks like you are interested in nodes that form the triangle element corners and not the midside nodes. Two opt...

10 days ago | 1

| accepted

Answered

PDETool temperature gradient-dependent internal heat generation

Hi Tadeu, My apologies, this is a bug in detecting pseudo-nonlinearity. Solver does not pass solution and its derivative to cus...

PDETool temperature gradient-dependent internal heat generation

Hi Tadeu, My apologies, this is a bug in detecting pseudo-nonlinearity. Solver does not pass solution and its derivative to cus...

10 days ago | 0

| accepted

Answered

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...

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...

12 days ago | 0

| accepted

Answered

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 (...

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 (...

15 days ago | 0

Answered

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. ...

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. ...

15 days ago | 0

Answered

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. ...

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. ...

16 days ago | 0

| accepted

Answered

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...

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...

23 days ago | 0

Answered

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...

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...

24 days ago | 0

Answered

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 ...

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 ...

29 days ago | 0

| accepted

Answered

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...

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...

1 month ago | 0

| accepted

Answered

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...

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...

1 month ago | 0

| accepted

Answered

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...

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...

1 month ago | 0

Answered

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...

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...

1 month ago | 0

| accepted

Answered

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...

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...

1 month ago | 0

| accepted

Answered

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...

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...

1 month ago | 0

| accepted

Answered

3D Magnetostatics in the Presence of a Current Source via PDE Toolbox

Thanks for taking time to explain the problem with such a detail and for providing the reproduction code. I tried to understand ...

3D Magnetostatics in the Presence of a Current Source via PDE Toolbox

Thanks for taking time to explain the problem with such a detail and for providing the reproduction code. I tried to understand ...

2 months ago | 1

Answered

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...

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...

2 months ago | 0

Answered

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...

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...

2 months ago | 0

Answered

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....

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....

2 months ago | 0

| accepted

Answered

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...

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...

2 months ago | 0

| accepted

Answered

Import a 2D STL File

The keyword here is "planar". Is your geomtry planar? Regards, Ravi

Import a 2D STL File

The keyword here is "planar". Is your geomtry planar? Regards, Ravi

2 months ago | 0

Answered

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...

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...

2 months ago | 0

Answered

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? ...

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? ...

2 months ago | 0

Answered

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...

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...

2 months ago | 0

| accepted

Answered

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 ...

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 ...

2 months ago | 0

| accepted

Answered

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...

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...

3 months ago | 0

| accepted

Answered

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...

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...

3 months ago | 0

| accepted

Answered

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...

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...

3 months ago | 0

| accepted