Modeling a Multi Tubular Membrane Reactor!

Hello everybody,

I'm new here in the forum and have been using Matlab for some time and have been using Star CCM+ for a little longer to simulate chemical reactions in fixed beds. Is it possible to simulate a porous zone in FeaTool? Can I add a membrane to it? At Star CCM+, I can simply merge two geometries and define the wall boundary as an interface as a membrane and the region as a porous zone (or two or three regions). It would be good to know whether this also works with FeaTool? Does anyone have any experience?

I also wonder if the FeaTool models are implemented in Simulink? Then you could theoretically simulate a process flow sheet like in Aspen or gPROMS.

Best regards

CFD2D

> Is it possible to simulate a porous zone in FeaTool?

Yes, FEATool comes with pre-defined equations for Darcy's Law and Brinkman equations for porous media flow. If your model uses some other PDE for porous media you would have to define this yourself using the Custom Equation physics mode and the FEATool PDE syntax. The available pre-defined and built-in physics modes are listed and clearly defined here

https://www.featool.com/doc/physics.html#phys_modes

> Can I add a membrane to it?

FEATool supports modeling with multiple boundaries and subdomains one of which you could designate as a membrane. As above, how much work you have to do yourself depends on if the equation for your membrane falls within one of the available pre-defined ones or not.

> I also wonder if the FeaTool models are implemented in Simulink?

FEATool models can not directly be loaded in to Simulink and vice versa. However, as FEATool is written in Matlab and models can be exported and run as simple m-file scripts you can write functions to call (and be called from) other Matlab toolboxes (including Simulink). Again there is nothing ready out of the box for this so you would have to do the implementation work yourself. The public FEATool Matlab function API is listed in the link below:

https://www.featool.com/doc/files.html

Precise Simulation wrote

> Is it possible to simulate a porous zone in FeaTool?

Yes, FEATool comes with pre-defined equations for Darcy's Law and Brinkman equations for porous media flow. If your model uses some other PDE for porous media you would have to define this yourself using the Custom Equation physics mode and the FEATool PDE syntax. The available pre-defined and built-in physics modes are listed and clearly defined here

https://www.featool.com/doc/physics.html#phys_modes

That sounds good. I've looked at a few tools and I'm optimistic. I was thinking more of an Ergun equation. But if you can create equations yourself, that's great! Such problems have already been dealt with in OpenFoam and if you can use all OpenFoam solvers, you can also tinker one yourself together. Or do I get the basic concept wrong?

Precise Simulation wrote

> Can I add a membrane to it?

FEATool supports modeling with multiple boundaries and subdomains one of which you could designate as a membrane. As above, how much work you have to do yourself depends on if the equation for your membrane falls within one of the available pre-defined ones or not.

That also sounds very promising.

Precise Simulation wrote

> I also wonder if the FeaTool models are implemented in Simulink?

FEATool models can not directly be loaded in to Simulink and vice versa. However, as FEATool is written in Matlab and models can be exported and run as simple m-file scripts you can write functions to call (and be called from) other Matlab toolboxes (including Simulink). Again there is nothing ready out of the box for this so you would have to do the implementation work yourself. The public FEATool Matlab function API is listed in the link below:

https://www.featool.com/doc/files.html

Ok, so I think its possible to create a whole process flowsheet with multiple parts of models
I saw that you can optimize the geometry in FEATool. For example, I've seen that another software can do this too. I would like to optimize the distance between the tubes in the tube bundle reactor so that the flow of the cooling medium is low, but the conversion of the reaction localizes its optimum. In another software this is only possible in a 2D simulation. In Star CCM + you can do this via the Design Manager. Can such cases also be dealt with in FEATool?

I am currently looking for a suitable CFD software for my PhD that can cover these cases and would not like to spend so much money "for free" now.

Thanks for your help.

CFD2D

PS: Please delete the another post (its written my real name, thanks ;-))

CFD2D wrote

I was thinking more of an Ergun equation. But if you can create equations yourself, that's great!

Yes, you can define your own PDEs or modify the pre-defined physics modes, see for example

https://www.featool.com/doc/physics.html#phys_ce

CFD2D wrote

Such problems have already been dealt with in OpenFoam and if you can use all OpenFoam solvers, you can also tinker one yourself together. Or do I get the basic concept wrong?

Currently you can not use _all_ OpenFOAM solvers as it would involve far too much work to write custom interfaces for them all. There are built-in interfaces for laminar and turbulent single phase flow, as well as compressible Euler equations which correspond to the simpleFoam, pimpleFoam, and rhoCentralFoam solvers. If you need to use another solver you could possibly use FEATool to set up/export mesh and case files, run your custom solver externally, and re-import the solutions for postprocessing/visualization.

CFD2D wrote

Ok, so I think its possible to create a whole process flowsheet with multiple parts of models
I saw that you can optimize the geometry in FEATool. I would like to optimize the distance between the tubes in the tube bundle reactor so that the flow of the cooling medium is low, but the conversion of the reaction localizes its optimum. In Star CCM + you can do this via the Design Manager. Can such cases also be dealt with in FEATool?

There is not built-in functionality for optimization, but you can certainly use the FEATool functions with the MATLAB Optimization toolbox as has been done by Prof. Yamazaki (note that there is no in-house expertise to help with optimization of this type)

https://www.featool.com/model-showcase/03_structural_mechanics_07_topology_optimization1

or parameter minimization and root finding with the fminbnd and fzero functions

https://www.featool.com/tutorial/2019/02/11/parameter-minimization-and-potential-flow-over-wing-profile.html
https://www.featool.com/tutorial/2019/01/14/inverse-fea-modeling-and-parameter-search-using-matlab-functions.html

or just setting up simple parametric runs

https://www.featool.com/tutorial/2017/11/13/cad-import-and-parametric-stress-displacement-simulation
https://www.featool.com/tutorial/2015/09/09/parametric-studies-with-featool-m-script-model-files

Note, that there is currently no GUI functionality for setting up and running parametric or optimization studies (like I assume StarCCM+ Design Manager is) so everything would have do be done I m-script file.

Precise Simulation wrote

CFD2D wrote

I was thinking more of an Ergun equation. But if you can create equations yourself, that's great!

Yes, you can define your own PDEs or modify the pre-defined physics modes, see for example

https://www.featool.com/doc/physics.html#phys_ce

But can i couple more than one Equation? I need ergun for pressure drop.. than i need convection and Diffusion.. than i need NS.. and I have to Custom all Equation about mixing rules and and and..

Precise Simulation wrote

CFD2D wrote

Such problems have already been dealt with in OpenFoam and if you can use all OpenFoam solvers, you can also tinker one yourself together. Or do I get the basic concept wrong?

Currently you can not use _all_ OpenFOAM solvers as it would involve far too much work to write custom interfaces for them all. There are built-in interfaces for laminar and turbulent single phase flow, as well as compressible Euler equations which correspond to the simpleFoam, pimpleFoam, and rhoCentralFoam solvers. If you need to use another solver you could possibly use FEATool to set up/export mesh and case files, run your custom solver externally, and re-import the solutions for postprocessing/visualization.

Ok But i need to couple Solver like reactingfoam and multiphasefoam.. But than i can directly use Openfoam I think

Precise Simulation wrote

CFD2D wrote

Ok, so I think its possible to create a whole process flowsheet with multiple parts of models
I saw that you can optimize the geometry in FEATool. I would like to optimize the distance between the tubes in the tube bundle reactor so that the flow of the cooling medium is low, but the conversion of the reaction localizes its optimum. In Star CCM + you can do this via the Design Manager. Can such cases also be dealt with in FEATool?

There is not built-in functionality for optimization, but you can certainly use the FEATool functions with the MATLAB Optimization toolbox as has been done by Prof. Yamazaki (note that there is no in-house expertise to help with optimization of this type)

https://www.featool.com/model-showcase/03_structural_mechanics_07_topology_optimization1

or parameter minimization and root finding with the fminbnd and fzero functions

https://www.featool.com/tutorial/2019/02/11/parameter-minimization-and-potential-flow-over-wing-profile.html
https://www.featool.com/tutorial/2019/01/14/inverse-fea-modeling-and-parameter-search-using-matlab-functions.html

or just setting up simple parametric runs

https://www.featool.com/tutorial/2017/11/13/cad-import-and-parametric-stress-displacement-simulation
https://www.featool.com/tutorial/2015/09/09/parametric-studies-with-featool-m-script-model-files

Note, that there is currently no GUI functionality for setting up and running parametric or optimization studies (like I assume StarCCM+ Design Manager is) so everything would have do be done I m-script file.

I know that is any GUI but it’s possible to optimise the Shape in Matlab is saw :)

CFD2D

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CFD2D wrote

 But can i couple more than one Equation? I need ergun for pressure drop.. than i need convection and Diffusion.. than i need NS.. and I have to Custom all Equation about mixing rules and and and..

Yes, you can couple any number of equations, but be aware that the more couplings you have the more non-linear the problem might be and become more difficult and take longer to solve.

CFD2D wrote

Ok But i need to couple Solver like reactingfoam and multiphasefoam.. But than i can directly use
Openfoam I think

The reactingfoam and multiphasefoam OpenFOAM solvers are not available, but you could maybe use the GUI to set up and export mesh and case files

https://www.featool.com/doc/openfoam.html#of_edit

Precise Simulation wrote

CFD2D wrote

 But can i couple more than one Equation? I need ergun for pressure drop.. than i need convection and Diffusion.. than i need NS.. and I have to Custom all Equation about mixing rules and and and..

Yes, you can couple any number of equations, but be aware that the more couplings you have the more non-linear the problem might be and become more difficult and take longer to solve.

I have 48 cores and i have some time for do this :-)
But than I will need another solver for example to solve my membran probem.. is it possible to run a simulation on variable Cores?

Precise Simulation wrote

CFD2D wrote

Ok But i need to couple Solver like reactingfoam and multiphasefoam.. But than i can directly use
Openfoam I think

The reactingfoam and multiphasefoam OpenFOAM solvers are not available, but you could maybe use the GUI to set up and export mesh and case files

https://www.featool.com/doc/openfoam.html#of_edit

I read this fast but I understood that i can export my FEA Simulation to run it in Openfoam with the Openfoam Solver? But than maybe its better to use directly OpenFoam? Hmmm
If FEA implement all OpenFoam Solver and if it possible to couple the Solver than FEATool I think one of the best CFD Software.. I have a vision :-D

CFD2D

CFD2D wrote

I have 48 cores and i have some time for do this :-)
But than I will need another solver for example to solve my membran probem.. is it possible to run a simulation on variable Cores?

Due to MATLAB not being very parallelizable FEATool and the built-in solvers only run in serial mode. But you can directly convert FEATool models to FEniCS FEA models which was designed around MPI parallelization so you can solve multiphysics models using FEniCS in parallel mode (FEATool and FEniCS uses the same FEM discretization so the solutions should be identical independent of which solver you use).

https://www.featool.com/tags/fenics

Precise Simulation wrote

CFD2D wrote

I have 48 cores and i have some time for do this :-)
But than I will need another solver for example to solve my membran probem.. is it possible to run a simulation on variable Cores?

Due to MATLAB not being very parallelizable FEATool and the built-in solvers only run in serial mode. But you can directly convert FEATool models to FEniCS FEA models which was designed around MPI parallelization so you can solve multiphysics models using FEniCS in parallel mode (FEATool and FEniCS uses the same FEM discretization so the solutions should be identical independent of which solver you use).

https://www.featool.com/tags/fenics

Hmmm ok but I need my own OpenFoam Solver.. so I think that i cant use FEATool for my cases :-(. I hope in the Future it will have more functionality about the solver

Hello Dear,

I saw that you made some extensions. I believe all my concerns have been resolved with the updates? I just installed FeaTool again and wanted to ask whether the walls can also be displayed as membranes in the boundary layers?

CFD2D

CFD2D wrote

I just installed FeaTool again and wanted to ask whether the walls can also be displayed as membranes in the boundary layers?

Hi, I'm not quite sure what kind of display or visualization you are looking for. Could you explain in a little more detail?

Precise Simulation wrote

CFD2D wrote

I just installed FeaTool again and wanted to ask whether the walls can also be displayed as membranes in the boundary layers?

Hi, I'm not quite sure what kind of display or visualization you are looking for. Could you explain in a little more detail?

We want to simulate a membrane reactor and FeaTool has made very good extensions. Since it is so super compact with Matlab, we want to give it a chance.

As an example, we would like to show that the membrane only lets through one component of the reaction mass and not others around it.

💪

CFD2D wrote

Precise Simulation wrote

CFD2D wrote

I just installed FeaTool again and wanted to ask whether the walls can also be displayed as membranes in the boundary layers?

Hi, I'm not quite sure what kind of display or visualization you are looking for. Could you explain in a little more detail?

We want to simulate a membrane reactor and FeaTool has made very good extensions. Since it is so super compact with Matlab, we want to give it a chance.

As an example, we would like to show that the membrane only lets through one component of the reaction mass and not others around it.

Yes, that sounds great, I still don't quite understand the question "whether the walls can also be displayed as membranes in the boundary layers". Walls/boundaries are visualized as surfaces, the mesh faces (in 3D) tagged as external or internal, you can plot any expression on them as "surface plot", but I don't quite know now a membrane would be visualized?

Precise Simulation wrote

CFD2D wrote

Precise Simulation wrote

CFD2D wrote

I just installed FeaTool again and wanted to ask whether the walls can also be displayed as membranes in the boundary layers?

Hi, I'm not quite sure what kind of display or visualization you are looking for. Could you explain in a little more detail?

We want to simulate a membrane reactor and FeaTool has made very good extensions. Since it is so super compact with Matlab, we want to give it a chance.

As an example, we would like to show that the membrane only lets through one component of the reaction mass and not others around it.

Yes, that sounds great, I still don't quite understand the question "whether the walls can also be displayed as membranes in the boundary layers". Walls/boundaries are visualized as surfaces, the mesh faces (in 3D) tagged as external or internal, you can plot any expression on them as "surface plot", but I don't quite know now a membrane would be visualized?

I'm sorry. “Displayed” is the wrong word. You shouldn't see anything in the simulation, but the simulation should calculate with a membrane as a wall (only permeable for certain substances).

yes, a concentration or flow profile can then simply be displayed using a surface plot💪!

CFD2D wrote

The simulation should calculate with a membrane as a wall (only permeable for certain substances).

There is currently no pre-defined membrane boundary conditions. What you probably want is to define a Flux (Neumann) boundary condition where the magnitude of the Flux depends on a combination of concentrations etc. If you know specifically how the PDE of your membrane boundary condition looks like it would likely not be that hard to define.

Precise Simulation wrote

CFD2D wrote

The simulation should calculate with a membrane as a wall (only permeable for certain substances).

There is currently no pre-defined membrane boundary conditions. What you probably want is to define a Flux (Neumann) boundary condition where the magnitude of the Flux depends on a combination of concentrations etc. If you know specifically how the PDE of your membrane boundary condition looks like it would likely not be that hard to define.

Yes but it's hard to define if you using multibody.. but with FEA its impossible to use multibody: like i showed in another thread "https://i.imgur.com/FuCFpwI.png"

And how to use a part with more than one subdomains (& Boundarylayer) in FEA to show a membrane process? A membrane seperate two parts (multibody). In openfoam is it possible.

Best Regards
CFD2D