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. ...

2 years 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. ...

2 years 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...

2 years 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...

2 years 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 ...

2 years 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...

2 years 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...

2 years ago | 1

| 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...

2 years 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...

2 years 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...

2 years 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...

2 years ago | 0

| accepted

Answered

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 ...

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 ...

2 years ago | 2

| accepted

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 years 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 years 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 years 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 years 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

3 years 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...

3 years 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? ...

3 years 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...

3 years 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 ...

3 years 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 years 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 years 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 years ago | 1

| accepted

Answered

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...

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...

3 years ago | 0

| accepted

Answered

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...

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...

3 years ago | 1

| accepted

Answered

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...

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...

3 years ago | 1

Answered

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...

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...

3 years ago | 0

| accepted

Answered

Solving PDE for Hygromechanical Coupling with f coefficient as a function of previous PDE results

You should be all set if you replace the last two lines in your function with the following one line: fx = [gradx.'.*coefRGx;gr...

Solving PDE for Hygromechanical Coupling with f coefficient as a function of previous PDE results

You should be all set if you replace the last two lines in your function with the following one line: fx = [gradx.'.*coefRGx;gr...

3 years ago | 0

| accepted

Answered

Error using deval in pde toolbox

Hi SS, The warning: Warning: Failure at t=1.307250e+00. Unable to meet integration tolerances without reducing the step size...

Error using deval in pde toolbox

Hi SS, The warning: Warning: Failure at t=1.307250e+00. Unable to meet integration tolerances without reducing the step size...

3 years ago | 0

| accepted