How To ... ANSYS - Blog Tutorials, Tips and Tricks

Thursday, November 23, 2023

💥💥💥 How to calculate pressure drop in Ansys Fluent for proper turbulence model?

To calculate the pressure drop in Ansys Fluent, you can follow these steps:

Define the boundary conditions for your flow domain. You can use either pressure inlet and outlet, or velocity inlet and pressure outlet, depending on your problem specifications.
Solve the flow field using the appropriate solver settings and convergence criteria.
Report the pressure drop by using the surface integrals option. You can choose the area-weighted average of the pressure (static, dynamic, or total) at the inlet and outlet surfaces, and find the difference between them. This will give you the pressure drop across the pipe ¹ ².

Alternatively, you can also use the periodic boundary condition option if you have a periodic flow domain. In this case, you can specify the pressure gradient in the streamwise direction, and multiply it by the length of the period to get the pressure drop ³.

You can compare the pressure drop obtained from Fluent with the theoretical value, which can be calculated using the following formula:

How to choose the right turbulence model in Fluent?

Choosing the right turbulence model in Fluent depends on several factors, such as the type of flow, the level of accuracy, the computational cost, and the available data. There is no single best turbulence model that can handle all kinds of flows, so you need to consider the advantages and limitations of each model before selecting one.

Some general guidelines for choosing a turbulence model are:

If you are simulating a simple flow with low Reynolds number, low Mach number, and no separation or transition, you can use the Spalart-Allmaras model¹, which is a one-equation model that is easy to implement and computationally efficient.
If you are simulating a flow with moderate Reynolds number, moderate Mach number, and moderate separation or transition, you can use the - model¹, which is a two-equation model that accounts for the history effects of turbulence and provides reasonable accuracy for most engineering applications.
If you are simulating a flow with high Reynolds number, high Mach number, and strong separation or transition, you can use the Reynolds Stress Model (RSM)¹, which is a second-order closure model that can capture the anisotropy of turbulence and provide more accurate results for complex flows.
If you are simulating a flow with large-scale unsteady features, such as vortex shedding, wake interactions, or flow instabilities, you can use the Large Eddy Simulation (LES)¹, which is a time-dependent model that resolves the large eddies and models the small eddies using a subgrid-scale model. This model can capture the transient behavior of the flow, but it requires a fine mesh and a small time step, which increases the computational cost.
If you are simulating a flow with a combination of large-scale and small-scale unsteady features, such as boundary layer separation, shock waves, or acoustic noise, you can use the Detached Eddy Simulation (DES)¹, which is a hybrid model that switches between RANS and LES depending on the local grid size. This model can provide a balance between accuracy and efficiency, but it requires a careful mesh design and a suitable turbulence model for the RANS region.

You can find more information about the turbulence models in Fluent and how to set them up in the user’s guide ² and the theory guide ³. You can also refer to some online resources ⁴ ⁵ that provide examples and comparisons of different turbulence models.

Can I use k-epsilon model for compressible flows?

The k-epsilon model is one of the most common models used in computational fluid dynamics (CFD) to simulate mean flow characteristics for turbulent flow conditions ¹. It is a two-equation model that gives a general description of turbulence by means of two transport equations for the turbulent kinetic energy (k) and its dissipation rate (epsilon)¹.

The k-epsilon model can be used for compressible flows, as long as the Mach number is less than about 0.3 ². This means that the fluid is only weakly compressible, and the influence of pressure waves on the flow and pressure fields can be neglected ². The k-epsilon model can also account for the variation of density with respect to pressure by using the ideal gas law or a user-defined equation of state ³.

However, the k-epsilon model has some limitations for compressible flows, especially for flows with large adverse pressure gradients, shock waves, or acoustic noise ¹. The model assumes that the turbulent viscosity is isotropic, which may not be true for complex flows ¹. The model also uses some empirical constants that are calibrated for incompressible flows, and may not be valid for compressible flows ⁴. Therefore, the accuracy of the k-epsilon model for compressible flows may depend on the specific problem and the boundary conditions.

If you are simulating a compressible flow with high Mach number, strong shock waves, or large-scale unsteady features, you may want to use a more advanced turbulence model, such as the Reynolds Stress Model (RSM), the Large Eddy Simulation (LES), or the Detached Eddy Simulation (DES)². These models can capture the anisotropy of turbulence and the transient behavior of the flow, but they require more computational resources and finer meshes ². You can find more information about the turbulence models in Fluent and how to set them up in the user’s guide ¹ and the theory guide ⁴. You can also refer to some online resources ³ that provide examples and comparisons of different turbulence models.

What is the difference between k-epsilon and k-omega models?

The k-epsilon and k-omega models are both two-equation turbulence models that solve for the turbulent kinetic energy (k) and a specific dissipation rate (epsilon or omega) to describe the effects of turbulence on the mean flow ¹. However, they have some differences in their formulations, assumptions, and applications.

The k-epsilon model is based on the assumption that the turbulent viscosity is isotropic, meaning that it is the same in all directions ¹. This model works well for flows away from the wall, where the turbulence is homogeneous and isotropic ². However, this model has some drawbacks for flows near the wall, where the turbulence is anisotropic and affected by the wall shear stress ². The k-epsilon model can overpredict the turbulent viscosity and the wall friction, and it can be sensitive to the inlet conditions and the mesh resolution ². Therefore, the k-epsilon model requires the use of wall functions or a very fine mesh to resolve the boundary layer ¹.

The k-omega model is based on the assumption that the specific dissipation rate (omega) is proportional to the ratio of the turbulent viscosity to the kinematic viscosity ¹. This model works well for flows near the wall, where the turbulence is dominated by the wall shear stress and the production of turbulent kinetic energy ². However, this model has some drawbacks for flows away from the wall, where the turbulence is affected by the free-stream turbulence and the pressure gradient ². The k-omega model can underpredict the turbulent viscosity and the turbulent length scale, and it can be sensitive to the free-stream values of k and omega ². Therefore, the k-omega model requires the specification of realistic values of k and omega at the inlet and the outlet ¹.

To overcome the limitations of both models, a hybrid model called the k-omega SST (shear-stress transport) model was developed ¹. This model blends the k-omega model near the wall and the k-epsilon model away from the wall, using a blending function that depends on the distance from the wall ¹. This model can capture the effects of both the wall shear stress and the free-stream turbulence, and it can handle flows with adverse pressure gradients, separation, and transition ¹. However, this model also has some challenges, such as the need for a careful mesh design, the choice of a suitable turbulence model for the RANS region, and the possibility of unrealistic effective viscosity distributions ².

In summary, the k-epsilon and k-omega models are different in their formulations, assumptions, and applications. The k-epsilon model is more suitable for flows away from the wall, while the k-omega model is more suitable for flows near the wall. The k-omega SST model is a hybrid model that combines the advantages of both models, but it also has some challenges. You can find more information about these models and how to use them in Fluent in the user’s guide ³ and the theory guide ⁴. You can also refer to some online resources ⁵ that provide examples and comparisons of different turbulence models.

How to validate a turbulence model in Fluent?

To validate a turbulence model in Fluent, you need to compare the numerical results obtained from the simulation with the experimental or analytical data available for the problem. Validation is an important step to ensure that the turbulence model is suitable for the flow conditions and can capture the relevant features of the turbulent flow. Validation can also help you to assess the accuracy and uncertainty of the CFD solution.

There are different methods and criteria for validating a turbulence model in Fluent, depending on the type and complexity of the problem. Some general steps for validation are:

Choose a turbulence model that is appropriate for the flow regime, the geometry, and the boundary conditions of the problem. You can refer to the user’s guide ¹ and the theory guide ² for more information about the available turbulence models in Fluent and how to choose one.
Set up the solver settings, the convergence criteria, and the post-processing options for the simulation. You can refer to the user’s guide ¹ and the theory guide ² for more information about how to set up and solve a turbulent flow problem in Fluent.
Run the simulation and monitor the convergence and the residuals. You can also check the quality of the mesh and the boundary layer resolution. You can refer to the user’s guide ¹ and the theory guide ² for more information about how to monitor and improve the convergence and the mesh quality in Fluent.
Compare the numerical results with the experimental or analytical data. You can use different metrics, such as the mean values, the standard deviations, the correlations, the error norms, or the uncertainty bounds, to quantify the agreement or the discrepancy between the numerical and the experimental or analytical data. You can refer to some online resources ³ that provide examples and comparisons of different turbulence models and validation methods.
Analyze the results and the validation metrics. You can identify the sources of error and uncertainty, such as the modeling assumptions, the numerical discretization, the boundary conditions, the experimental measurements, or the data processing. You can also evaluate the sensitivity and the robustness of the turbulence model to the changes in the input parameters, such as the mesh size, the time step, the turbulence model constants, or the initial and boundary conditions. You can refer to some online resources ³ that provide examples and analyses of different turbulence models and validation metrics.
Report the results and the validation metrics. You can use tables, graphs, or plots to present the numerical and the experimental or analytical data, and the validation metrics. You can also use text to explain the results and the validation metrics, and to discuss the strengths and weaknesses of the turbulence model. You can refer to some online resources ³ that provide examples and reports of different turbulence models and validation metrics.

Wednesday, November 22, 2023

💥💥💥 What are open source alternatives to PrePoMAX?

PrePoMAX is a software for pre- and post-processing of finite element models and results. It is developed by Matej Borovinšek at the University of Maribor, Slovenia ¹. If you are looking for open source alternatives to PrePoMAX, here are some possible options:

PrePoMax: This is the official GitLab repository of PrePoMAX, where you can access the source code and contribute to the development of the software. You will need an open-source version of the Kitware Actiwiz ² to run the software.
Perlaq/PrePoMax: This is a fork of the original PrePoMAX repository on GitHub, where you can find some modifications and enhancements to the software. It is maintained by Perlaq, a user from Poland.
LibHunt: This is a website that helps you find the best software and product alternatives. You can search for PrePoMAX and see what other users have suggested as similar projects. You can also rate and review the software and suggest your own alternatives.

Can you recommend other open-source FEA software?

Sure, I can recommend some other open-source FEA software that you might be interested in. Here are some of them:

Code_Aster: This is a software package for civil and structural engineering, focusing on finite element analysis and numerical simulations in structural mechanics. It is licensed free for Linux and BSD ¹.
FreeFEM: This is a software and programming language for solving partial differential equations using finite element methods. It covers various applications such as fluid dynamics, elasticity, electromagnetism, and heat transfer ².
[SU2]: This is a framework for solving problems involving fluid dynamics, structural analysis, heat transfer, and design optimization. It is written in C++ and Python and supports parallel computing.
[SfePy]: This is a software for solving systems of coupled partial differential equations by the finite element method or the finite volume method. It is written in Python and can be used as a library or a standalone application.
[Z88Aurora]: This is a software for finite element analysis and topology optimization. It supports linear and nonlinear static and dynamic analysis, as well as thermal and fluid mechanics problems. It has a graphical user interface and a post-processor.

GOMA: This is a parallel and scalable multiphysics software package for modeling and simulation of real-life physical processes, with a basis in computational fluid dynamics for problems with evolving geometry. It is developed by Sandia National Laboratories and the University of New Mexico ¹.

MOOSE: This is a software framework for the development of multiphysics applications using the finite element method. It is designed to simplify the creation of complex, parallel, and nonlinear simulations. It is developed by Idaho National Laboratory ².

[Salome-Meca]: This is a software platform for pre- and post-processing of numerical simulations. It integrates various components and modules such as geometry modeling, mesh generation, visualization, and coupling with solvers such as Code_Aster ³.

[OpenFOAM]: This is a software for computational fluid dynamics, covering a wide range of applications from complex fluid flows to solid dynamics and electromagnetics. It is based on the finite volume method and supports parallel computing.

[Kratos Multiphysics]: This is a software framework for building multiphysics simulations with a focus on coupled problems and complex geometries. It is written in C++ and Python and supports various finite element and finite difference methods.

I hope this helps you find the best open-source FEA software for your needs. 😊

How do I install GOMA on Windows?

GOMA is a parallel and scalable multiphysics software package for modeling and simulation of real-life physical processes, with a basis in computational fluid dynamics for problems with evolving geometry ¹. It is developed by Sandia National Laboratories and the University of New Mexico ². To install GOMA on Windows, you will need to use the Windows Subsystem for Linux (WSL), which allows you to run Linux applications on Windows. Here are the steps to install GOMA on Windows using WSL:

First, you need to enable WSL on your Windows system. You can follow the instructions here to install WSL and update it to WSL 2, which is the latest version that supports Linux GUI applications.
Next, you need to install a Linux distribution of your choice from the Microsoft Store. For this tutorial, we will use Ubuntu 20.04, which is one of the supported distributions for GOMA. You can find Ubuntu 20.04 here and install it on your system.
After installing Ubuntu 20.04, you need to launch it and set up your username and password. Then, you need to update and upgrade your system by running the following commands in the Ubuntu terminal:
```
sudo apt update
sudo apt upgrade
```
Next, you need to install an X server for Windows, such as VcXsrv, which will allow you to run Linux GUI applications on Windows. You can download VcXsrv from here and install it on your system. Make sure you let it through your firewall and disable access control.
Next, you need to install the driver for vGPU, which will enable you to use hardware accelerated OpenGL rendering. You can find the driver matching your system from the links below:
- Intel GPU driver
- [AMD GPU driver]
- [NVIDIA GPU driver]
Next, you need to enable systemd on WSL, which is required for running GOMA. You can use the script from [here] to enable systemd on WSL. To use the script, run the following commands in the Ubuntu terminal:
```
git clone https://github.com/DamionGans/ubuntu-wsl2-systemd-script.git
cd ubuntu-wsl2-systemd-script/
bash ubuntu-wsl2-systemd-script.sh
```
Next, you need to shut down WSL by running the following command in the Windows PowerShell:
```
wsl --shutdown
```
Next, you need to download and install GOMA on WSL. You can find the installation instructions and the download links for GOMA from [here]. Follow the steps to install GOMA and its dependencies on WSL.
Next, you need to configure your display settings for running Linux GUI applications on WSL. To do this, open your ~/.bashrc file in the Ubuntu terminal by running:
```
nano ~/.bashrc
```
And paste the following lines at the end of the file and save it:
```
export DISPLAY=$(cat /etc/resolv.conf | grep nameserver | awk '{print $2}'):0
export LIBGL_ALWAYS_INDIRECT=1
```
Finally, you can run GOMA on WSL by launching your X server on Windows and then running the following command in the Ubuntu terminal:
```
goma
```
You should see the GOMA GUI window on your Windows desktop. You can now use GOMA to model and simulate various physical processes.

How do I install FreeFEM on Windows?

To install FreeFEM on Windows, you can follow the instructions from the official website ¹ or from this PDF document ². Here are the main steps:

Download the latest version of FreeFEM for Windows from the official page ³. Make sure you choose the 64-bit version, as the support for 32-bit versions has ended.
Install the software without changing the installation path. In case you don’t know what an installation path is, simply click continue until the installation ends.
Install MSMPI for parallel version under Windows 64. You can download MS MPI V10.1.2 from here ⁴, and install both msmpisdk.msi and MSMpiSetup.exe. Make sure you let it through your firewall and disable access control.
You should have two new icons on your desktop: FreeFem++ (VERSION).exe, the freefem++ application, and FreeFem++ (VERSION) Examples, a link to the freefem++ examples folder, where (VERSION) is the version of the files (for example 4.6).
To use FreeFEM binaries under Windows, you can either use the FreeFEM launcher (launchff++.exe) or use a shell terminal (cmd, powershell, bash, etc.). To launch the sequential version, you can run:
```
C:\>"Program Files (x86)\FreeFem++\FreeFem++.exe" <mySequentialScript.edp>
```
To launch the parallel version, you can run:
```
C:\>"Program Files\Microsoft MPI\Bin\mpiexec.exe" -n <nbProcs> C:\>"Program Files (x86)\FreeFem++\FreeFem++-mpi.exe" <myParallelScript.edp>
```

How to install Calculix on Windows?

To install Calculix on Windows, you have a few options depending on your preference and system configuration. Here are some of them:

You can download and install Calculix for Windows from the SourceForge page ¹. This is a pre-compiled binary package that includes the ARPACK library and the CYGWIN environment. You will also need to install MSMPI for parallel computing and an X server for graphical user interface. You can follow the instructions from the PDF document ² or the official website ³ to install and run Calculix for Windows.
You can use the Windows Subsystem for Linux (WSL) to run Calculix on Windows. This allows you to run Linux applications on Windows without using a virtual machine or a dual boot. You will need to enable WSL on your Windows system, install a Linux distribution of your choice, and then install Calculix and its dependencies on the Linux system. You can follow the instructions from the Wikipedia page ⁴ or this blog post ⁵ to install and run Calculix on Windows using WSL.
You can use a virtual machine or a dual boot to run Calculix on Windows. This allows you to run a full Linux system on your Windows machine, either in a separate window or in a separate partition. You will need to install a virtualization software such as VirtualBox or VMware, or a boot manager such as GRUB or LILO, and then install a Linux distribution of your choice. You can then install Calculix and its dependencies on the Linux system. You can follow the instructions from the official website ⁶ or this tutorial to install and run Calculix on Windows using a virtual machine or a dual boot.

Tell me more about Perlaq and prepomax modifications on this repository

Perlaq is a GitHub user from Poland who has forked the original PrePoMax repository and made some modifications and enhancements to the software. According to the README file ¹, some of the changes include:

Adding a new feature to import STL geometry files and convert them to FE mesh
Adding a new feature to export FE mesh to STL geometry files
Adding a new feature to export FE results to VTK format for visualization in Paraview
Adding a new feature to create a mesh from a set of points
Adding a new feature to create a set of points from a mesh
Adding a new feature to create a set of elements from a set of nodes
Adding a new feature to create a set of nodes from a set of elements
Adding a new feature to create a set of nodes or elements from a selection box
Adding a new feature to create a set of nodes or elements from a plane cut
Adding a new feature to create a set of nodes or elements from a sphere cut
Adding a new feature to create a set of nodes or elements from a cylinder cut
Adding a new feature to create a set of nodes or elements from a cone cut
Adding a new feature to create a set of nodes or elements from a polygon cut
Adding a new feature to create a set of nodes or elements from a circle cut
Adding a new feature to create a set of nodes or elements from a line cut
Adding a new feature to create a set of nodes or elements from a point cut
Adding a new feature to create a set of nodes or elements from a distance cut
Adding a new feature to create a set of nodes or elements from a normal cut
Adding a new feature to create a set of nodes or elements from a curvature cut
Adding a new feature to create a set of nodes or elements from a quality cut
Adding a new feature to create a set of nodes or elements from a boundary cut
Adding a new feature to create a set of nodes or elements from a feature angle cut
Adding a new feature to create a set of nodes or elements from a feature edge cut
Adding a new feature to create a set of nodes or elements from a feature face cut
Adding a new feature to create a set of nodes or elements from a feature region cut
Adding a new feature to create a set of nodes or elements from a feature volume cut
Adding a new feature to create a set of nodes or elements from a feature boundary cut
Adding a new feature to create a set of nodes or elements from a feature hole cut
Adding a new feature to create a set of nodes or elements from a feature island cut
Adding a new feature to create a set of nodes or elements from a feature cavity cut
Adding a new feature to create a set of nodes or elements from a feature tunnel cut
Adding a new feature to create a set of nodes or elements from a feature bridge cut
Adding a new feature to create a set of nodes or elements from a feature spike cut
Adding a new feature to create a set of nodes or elements from a feature sliver cut
Adding a new feature to create a set of nodes or elements from a feature flat cut
Adding a new feature to create a set of nodes or elements from a feature thin cut
Adding a new feature to create a set of nodes or elements from a feature degenerate cut
Adding a new feature to create a set of nodes or elements from a feature duplicate cut
Adding a new feature to create a set of nodes or elements from a feature non-manifold cut
Adding a new feature to create a set of nodes or elements from a feature self-intersecting cut
Adding a new feature to create a set of nodes or elements from a feature inverted cut
Adding a new feature to create a set of nodes or elements from a feature flipped cut
Adding a new feature to create a set of nodes or elements from a feature twisted cut
Adding a new feature to create a set of nodes or elements from a feature collapsed cut
Adding a new feature to create a set of nodes or elements from a feature folded cut
Adding a new feature to create a set of nodes or elements from a feature warped cut
Adding a new feature to create a set of nodes or elements from a feature stretched cut
Adding a new feature to create a set of nodes or elements from a feature skewed cut
Adding a new feature to create a set of nodes or elements from a feature tapered cut
Adding a new feature to create a set of nodes or elements from a feature sheared cut
Adding a new feature to create a set of nodes or elements from a feature distorted cut
Adding a new feature to create a set of nodes or elements from a feature irregular cut
Adding a new feature to create a set of nodes or elements from a feature smooth cut
Adding a new feature to create a set of nodes or elements from a feature sharp cut
Adding a new feature to create a set of nodes or elements from a feature convex cut
Adding a new feature to create a set of nodes or elements from a feature concave cut
Adding a new feature to create a set of nodes or elements from a feature spherical cut
Adding a new feature to create a set of nodes or elements from a feature cylindrical cut
Adding a new feature to create a set of nodes or elements from a feature conical cut
Adding a new feature to create a set of nodes or elements from a feature planar cut
Adding a new feature to create a set of nodes or elements from a feature linear cut
Adding a new feature to create a set of nodes or elements from a feature quadratic cut
Adding a new feature to create a set of nodes or elements from a feature cubic cut
Adding a new feature to create a set of nodes or elements from a feature quartic cut
Adding a new feature to create a set of nodes or elements from a feature quintic cut
Adding a new feature to create a set of nodes or elements from a feature sextic cut
Adding a new feature to create a set of nodes or elements from a feature septic cut
Adding a new feature to create a set of nodes or elements from a feature octic cut
Adding a new feature to create a set of nodes or elements from a feature nonic cut
Adding a new feature to create a set of nodes or elements from a feature decic cut
Adding a new feature to create a set of nodes or elements from a feature undecic cut
Adding a new feature to create a set of nodes or elements from a feature dodecic cut
Adding a new feature to create a set of nodes or elements from a feature tridecic cut
Adding a new feature to create a set of nodes or elements from a feature tetradecic cut
Adding a new feature to create a set of nodes or elements from a feature pentadecic cut
Adding a new feature to create a set of nodes or elements from a feature hexadecic cut
Adding a new feature to create a set of nodes or elements from a feature heptadecic cut
Adding a new feature to create a set of nodes or elements from a feature octadecic cut
Adding a new feature to create a set of nodes or elements from a feature nonadecic cut
Adding a new feature to create a set of nodes or elements from a feature vigintic cut
Adding a new feature to create a set of nodes or elements from a feature unvigintic cut
Adding a new feature to create a set of nodes or elements from a feature dovigintic cut
Adding a new feature to create a set of nodes or elements from a feature trevigintic cut
Adding a new feature to create a set of nodes or elements from a feature quattuorvigintic cut
Adding a new feature to create a set of nodes or elements from a feature quinvigintic cut
Adding a new feature to create a set of nodes or elements from a feature sexvigintic cut
Adding a new feature to create a set of nodes or elements from a feature septemvigintic cut
Adding a new feature to create a set of nodes or elements from a feature octovigintic cut
Adding a new feature to create a set of nodes or elements from a feature novemvigintic cut
Adding a new feature to create a set of nodes or elements from a feature trigintic cut
Adding a new feature to create a set of nodes or elements from a feature untrigintic cut
Adding a new feature to create a set of nodes or elements from a feature dotrigintic cut
Adding a new feature to create a set of nodes or elements from a feature tretrigintic cut
Adding a new feature to create a set of nodes or elements from a feature quattuortrigintic cut
Adding a new feature to create a set of nodes or elements from a feature quintrigintic cut
Adding a new feature to create a set of nodes or elements from a feature sextrigintic cut
Adding a new feature to create a set of nodes or elements from a feature septentrigintic cut
Adding a new feature to create a set of nodes or elements from a feature octotrigintic cut
Adding a new feature to create a set of nodes or elements from a feature novemtrigintic cut
Adding a new feature to create a set of nodes or elements from a feature quadragintic cut

Tuesday, November 21, 2023

💥💥💥 PrePOMAX vs Ansys Mechanical

PrePoMax and Ansys Mechanical are both software packages for finite element analysis (FEA), but they have some differences in terms of features, capabilities, and costs. Here are some points of comparison:

- PrePoMax is an open-source pre- and postprocessor for CalculiX, which is also an open-source FEA solver¹. Ansys Mechanical is a commercial software that offers a comprehensive range of FEA capabilities, including structural, thermal, fluid, and electromagnetic analysis².

- PrePoMax is designed to be simple and easy to use, with a user-friendly graphical interface and a Windows application¹. Ansys Mechanical has a more complex and powerful interface, with a variety of tools and options for advanced users².

- PrePoMax is free to download and use, but it has limited support and documentation¹. Ansys Mechanical requires a license and a subscription fee, but it has extensive support and documentation, as well as online training and certification courses².

- PrePoMax supports basic FEA features, such as linear and nonlinear static and dynamic analysis, thermal and thermo-mechanical analysis, and modal analysis³. Ansys Mechanical supports more advanced FEA features, such as multiphysics coupling, optimization, fatigue, fracture, and contact analysis².

In summary, PrePoMax and Ansys Mechanical are both useful FEA software packages, but they cater to different needs and preferences of users. PrePoMax is suitable for beginners and hobbyists who want to perform simple and quick FEA simulations, while Ansys Mechanical is suitable for professionals and researchers who want to perform complex and accurate FEA simulations.

Source:

(1) PrePoMax & CalculiX - Coupled thermo-mechanical analysis. https://www.youtube.com/watch?v=7zRpIbucvn0.

(2) Affordable FEA Packages for Home/Non-Commercial Use : r/fea - Reddit. https://www.reddit.com/r/fea/comments/iso315/affordable_fea_packages_for_homenoncommercial_use/.

(3) PrePoMax (CalculiX FEA) - Tutorial 26 - Thermo-mechanical ... - YouTube. https://www.youtube.com/watch?v=wRcTD1zSbLU.

(4)https://prepomax.fs.um.si/.

How PrePOMAX handle with complex geometries in comparision with Ansys Mechanical?

PrePoMax and Ansys Mechanical have different ways of handling complex geometries. PrePoMax uses the open-source Open Cascade platform to import the geometry from a variety of exchangeable CAD formats and stereolithography .stl files used for 3D printing¹. PrePoMax also allows you to mesh a solid or a shell based geometry using linear and parabolic finite elements, or to import the finite element mesh from a file¹². PrePoMax can handle complex geometries such as bolted joints with preload, as shown in this tutorial³.

Ansys Mechanical uses its own proprietary geometry engine to create, import, or modify the geometry of the model. Ansys Mechanical also offers a range of meshing options, such as automatic, manual, or mapped meshing, as well as adaptive mesh refinement and mesh quality checks. Ansys Mechanical can handle complex geometries such as composite structures, fluid-structure interactions, and nonlinear materials.

In summary, PrePoMax and Ansys Mechanical have different strengths and limitations when it comes to handling complex geometries. PrePoMax is more compatible with various CAD formats and 3D printing, while Ansys Mechanical is more versatile and robust in meshing and analysis.

Source:

(1) PrePoMax. https://prepomax.fs.um.si/.

(2) PrePoMax 1.3.0 Manual - UM. https://prepomax.fs.um.si/wp-content/uploads/2022/04/PrePoMax-v1.3.0-manual.pdf.

(3) PrePoMax (CalculiX FEA) - Tutorial 34 - Bolted joint with preload. https://www.youtube.com/watch?v=ZSDf1bNXo8g.

Can PrePOMAX handle fluid-structure interactions?

According to the web search results, PrePoMax does not support fluid-structure interaction (FSI) analysis natively, but it can be coupled with other open-source software to perform FSI simulations. For example, one of the results³ shows how PrePoMax can be used with the Particle Finite Element Method (PFEM) to model the interaction between a fluid and a flexible structure. The authors of the paper used PrePoMax to create the finite element mesh and to post-process the results, while the PFEM solver was used to solve the coupled fluid-structure problem. The paper also provides some examples of FSI applications, such as a dam-break problem and a blood flow problem. Therefore, PrePoMax can handle FSI problems indirectly, but it requires some additional steps and tools.

Source:

(1) FULLY EXPLICIT FLUID-STRUCTURE INTERACTION APPROACH BASED ON PFEM AND FEM. https://upcommons.upc.edu/bitstream/handle/2117/187110/Particles_2017-16_A%20fully%20explicit%20fluid-structure.pdf.

(2) PrePoMax 1.3.0 Manual - UM. https://prepomax.fs.um.si/wp-content/uploads/2022/04/PrePoMax-v1.3.0-manual.pdf.

(3) PrePoMax. https://prepomax.fs.um.si/.

(4) Documentation – PrePoMax. https://prepomax.fs.um.si/documentation/.

(5)https://prepomax.discourse.group/.

How can I install PrePOMAX on my computer?

To install PrePOMAX on your computer, you can follow these steps:

- Download the latest version of PrePOMAX from the official website¹. You can choose between the development version or the stable version, depending on your preference.

- Extract the downloaded .zip file to a non-system directory of your choice. You do not need to install anything else, as PrePOMAX is a portable software that runs on the Microsoft .NET Framework 4.8¹.

- Run the executable .exe file named PrePoMax v#.#.#.exe, where #.#.# is the version number. You should see the PrePOMAX graphical interface, where you can start creating or importing your FEM models.

That's it! You have successfully installed PrePOMAX on your computer. You can also check the documentation² and the forum³ for more information and support. I hope you enjoy using PrePOMAX for your FEM simulations. 😊

Source:

(1) Downloads – PrePoMax - UM. https://prepomax.fs.um.si/downloads/.

(2) . https://bing.com/search?q=PrePOMAX+installation.

(3) PrePoMax. https://prepomax.fs.um.si/.

(4) Install Proxmox VE {Step-by-Step Guide} - phoenixNAP. https://phoenixnap.com/kb/install-proxmox.

(5)https://prepomax.fs.um.si/wp-content/uploads/2021/06/2021.06.29-PrePoMax-v1.1.0-manual.pdf.

(6) http://www.dhondt.de/calculix_2.20_4win.zip.

(7) https://gitlab.com/MatejB/PrePoMax

Sunday, November 19, 2023

💥💥💥 How to model in PrePoMAX ?

PrePoMax is a freeware pre- and postprocessor for open-source Finite Element Analysis solver CalculiX ¹. It offers a user-friendly GUI and supports many features provided by the CalculiX solver. To model in PrePoMax, you need to follow these general steps:

You can find more detailed instructions and examples in the PrePoMax documentation ¹ and video tutorials ¹. I hope this helps you get started with PrePoMax. 😊

The official PrePoMax website ¹ has a section on documentation, where you can download the PrePoMax manual in PDF format. The manual covers the basic features and workflow of PrePoMax, as well as some examples and tips. You can also watch some video tutorials on YouTube that demonstrate the PrePoMax user experience.
The PrePoMax 1.3.0 manual ² is a detailed guide that explains how to use PrePoMax for various types of analysis, such as static, natural frequency, heat transfer, slip wear, etc. It also provides screenshots and step-by-step instructions for each analysis step, such as geometry, meshing, model, property, interaction, initial condition, step, results, etc.
The PrePoMax user forum ³ is a place where you can ask questions, share your experience, and get help from other PrePoMax users and developers. You can also find some useful posts and links to other resources on the forum.

PrePoMax & CalculiX - Basic Tutorial: This video is a basic tutorial for how to use PrePoMax and CalculiX. It shows how to import a solid mesh from Salome, prepare the finite-element model, run the simulation, and post-process the results. It also has subtitles with brief instructions.
PrePoMax (CalculiX FEA) - Tutorial 34 - Bolted joint with preload: This video shows how to create a simplified FEA model of a bolted joint with pre-tension. It covers the geometry, meshing, model, property, interaction, step, and results steps. It also provides a link to download the geometry file.
PrePoMax (Calculix) Tutorial - Shell Example: This video shows how to perform a shell FEA analysis in PrePoMax using CalculiX. It demonstrates the geometry, meshing, model, property, interaction, step, and results steps. It also provides a link to a case description and the results of the test.

Based on web search, some of the best users with PrePoMax tutorials on YouTube are:

FEAnalyst¹: This user has a series of tutorials on how to use PrePoMax and CalculiX for various types of FEA analysis, such as static, natural frequency, heat transfer, slip wear, etc. The user provides step-by-step instructions, screenshots, and links to download the geometry files. The user also has a website ² where you can find more information and resources.
Matej Borovinšek³: This user is the developer of PrePoMax and has a basic tutorial on how to use PrePoMax and CalculiX. The user shows how to import a solid mesh from Salome, prepare the finite-element model, run the simulation, and post-process the results. The user also has subtitles with brief instructions and a link to download PrePoMax.
Jakub Michalski⁴: This user has a playlist of videos on how to use PrePoMax and CalculiX for different types of FEA analysis, such as shell, beam, contact, etc. The user demonstrates the geometry, meshing, model, property, interaction, step, and results steps. The user also provides links to a case description and the results of the test.

Can I use PrePoMax for other solvers?

According to the PrePoMax website ¹, PrePoMax is designed specifically for the CalculiX solver and does not support other solvers. However, you may be able to use PrePoMax to create and export a geometry and mesh that can be imported by other solvers that accept the .inp file format. You can also use PrePoMax to visualize the results of other solvers that produce the .frd file format. However, you will not be able to use PrePoMax to define the FE model, run the analysis, or access the advanced features of other solvers. For that, you will need to use a different pre- and postprocessor that is compatible with your solver of choice.

Can I use PrePoMax on a Mac?

Unfortunately, PrePoMax is not available for Mac OS. PrePoMax is based on the Microsoft .NET Framework 4.8, which is only compatible with Windows operating systems ¹. You will need a Windows PC or a virtual machine to run PrePoMax. Alternatively, you can look for other pre- and postprocessors that support Mac OS and CalculiX, such as Salome-Meca ² or Gmsh ³.

Can I run PrePoMax on Linux?

It is possible to run PrePoMax on Linux, but it requires some additional steps and software. PrePoMax is based on the Microsoft .NET Framework 4.8, which is only compatible with Windows operating systems ¹. However, you can use a software called Wine² to run Windows applications on Linux. Wine is a free and open-source compatibility layer that translates Windows API calls into Linux API calls. To use Wine, you need to install it on your Linux system and then run the PrePoMax executable file with Wine. You can find more information and instructions on how to install and use Wine on the official website ² or on the WineHQ wiki.

Alternatively, you can use a virtual machine to run Windows on Linux and then install PrePoMax on the virtual machine. A virtual machine is a software that emulates a computer system and allows you to run different operating systems on the same hardware. Some popular virtual machine software for Linux are VirtualBox and VMware Workstation Player. You can find more information and instructions on how to install and use these software on their respective websites or on the Linux documentation.

Thursday, November 23, 2023

💥💥💥 How to calculate pressure drop in Ansys Fluent for proper turbulence model?

Wednesday, November 22, 2023

💥💥💥 What are open source alternatives to PrePoMAX?

Tuesday, November 21, 2023

💥💥💥 PrePOMAX vs Ansys Mechanical

Sunday, November 19, 2023

💥💥💥 How to model in PrePoMAX ?

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