Community Profile

# Ravi Kumar

### University of Illinois

137 total contributions since 2016

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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...

4 days ago | 0

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...

4 days ago | 0

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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 ...

12 days ago | 1

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...

14 days ago | 0

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...

14 days ago | 0

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....

16 days ago | 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...

17 days ago | 0

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

1 month ago | 0

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...

1 month ago | 0

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? ...

1 month ago | 0

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...

1 month ago | 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 ...

1 month ago | 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...

1 month ago | 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...

2 months ago | 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...

2 months ago | 0

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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...

2 months ago | 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...

2 months ago | 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...

2 months ago | 1

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...

2 months ago | 0

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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 months ago | 0

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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...

4 months ago | 0

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Temperature-dependent boundary conditions
Do you have PDE Toolbox in your installed products list? You can check this by executing 'ver' at the command prompt. If so, di...

4 months ago | 0

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To activate both radiation and convection on the same boundary, combine them into one assignment as: thermalBC(thermalmodel,'Fa...

4 months ago | 0

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Temperature in a specific point with pde thermal
Yes! Check out the interpolateTemperature function.

5 months ago | 0

How to specify initial conditions for two different subdomains in PDE solver?
I suggest you to look at the programmatic workflow, refer to the programmatic workflow overview doc page. In the programmatic ...

5 months ago | 0

How to specify f coefficient function for arbitrarily located point sources within a domain.
If you want to use addtional arguments in computing f, then wrap the f coefficient function around the actual function that take...

5 months ago | 0

Determine locations struct used in PDE solver
You can write that code that you indented to use to "create a matrix that is of length N by M where ..." in the function itself....

5 months ago | 0

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Time-dependent thermal conductivity
Function should return values of k at all points requested by the solver, points are in the first argument. Update your funciton...

5 months ago | 0

| accepted