Why does chtMultiRegionTwoPhaseEulerFoam halt at "Constructing face momentum equations" without errors?
The fact that chtMultiRegionTwoPhaseEulerFoam stops at the "Constructing face momentum equations" stage without any error message suggests an issue with the initial conditions or case setup. Here are some potential causes to investigate:
Question: How to fix pressure field issues and continuity errors in an intermixingFoam simulation for simulating two mixing fluids in a rocket engine chamber?
I'd be glad to assist you with the pressure field and continuity errors you're encountering in your intermixingFoam simulation.
What are some potential solutions to address buoyantFoam crashes during mixed convection simulations in OpenFOAM?
I'd be glad to help you with the buoyantFoam crashes you're encountering in mixed convection simulations or when using higher-order schemes.
It sounds like you’re dealing with a challenging CFD problem. Convergence issues can often arise from the way boundary conditions are set up. Here are a few tips that might help you troubleshoot and resolve the issue:
The unexpected velocity increase in your partially filled stirred vessel simulation could stem from a few factors:
Hey everyone,
I have a weird problem with my simulation of a stirred vessel partially filled with water. Above the air-water interface, the velocity of water (UWater) gradually increases over time and I can't figure out why. I think this increase over time causes my simulation to fail after simulating a few seconds
I mostly used the case from this link as a reference: https://www.cemf.ir/simulating-two-p...sing-openfoam/
I can't figure out what the problem is for the increase. Does anyone know what could be the cause for this or had similar issues in the past?
There are two main approaches to porting the initial field from a StarCCM+ simulation to an OpenFOAM case:
* Using ccmToFoam: While ccmToFoam can convert the mesh, it may not directly translate the initial field data. You'll need to manipulate the converted data to match OpenFOAM's format.
In OpenFOAM, you can simulate rough wall effects in your pipe flow simulations using the roughWall function object. This function alters the logarithmic law of the wall to account for the increased drag caused by the roughness.
I am trying to install the OpenFOAM 11 version of thew software on my Windows server 22 OS through WSL. I followed the documentation based on the 4 steps mentioned here.
https://openfoam.org/download/source...g-environment/
While sourcing the bashrc file through my $HOME directory, I am getting the following errors as shown in the image attached. Do I need to make any changes in the User editable portion of the bashrc script?
To help with the 'mover' in OpenFOAM 11, specifically the 'interpolator' option.
While there seems to be a lack of readily available examples or tutorials on the 'interpolator' option in OpenFOAM 11's 'mover' dictionary, here's some insight that might be helpful:
Backflow in OpenFOAM simulations can arise from various factors, even when using the inletOutlet boundary condition. Here are some potential causes and solutions for your specific scenario:
There is the inconsistency in units for non-Newtonian viscosity calculations in the Herschel-Bulkley model. The inconsistency arises because the model expresses shear stress (tau) in units of N/m^2 (Pascals), while the shear rate (gamma_dot) is in units of s^-1 (reciprocal seconds).
The error message "Carrier phase curlUc interpolation object not set" in OpenFOAM indicates that a required interpolation object for the Saffman Mei lift force calculation is missing. Here's how to address this:
Converting rheology data to model parameters is definitely possible! Here's a general approach for fitting your complex rheology data (G*, G', and G'') to the PTT or Maxwell models using OpenFOAM:
I'd be glad to help you with the dynamic library error you're encountering in your OpenFOAM simulation. While I cannot provide specific instructions on copying and pasting due to the potential variations in file structures and operating systems, here are general guidelines that should help you resolve the issue:
The timeVaryingMappedFixedValue boundary condition in OpenFOAM allows you to prescribe values that vary in time and space on a patch. Here's a breakdown of its usage with the interFoam solver:
Ansys is a powerful commercial software suite, so there isn't a single free program that offers all its functionalities. However, depending on your specific needs, here are some free and open-source options that can handle various aspects of structural analysis similar to Ansys:
General Structural Analysis:
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Here are some of the best OpenFOAM tutorials for beginners to get you started:
Official Resources:
While OpenFOAM itself isn't officially supported on Windows, there are a couple of ways to run it on your Windows machine:
Windows Subsystem for Linux (WSL): This is the recommended approach by the OpenFOAM community. WSL allows you to run a Linux distribution like Ubuntu directly within Windows. You can then install OpenFOAM on the Linux subsystem and access it through the command line. This offers a more native OpenFOAM experience.
Docker: Docker provides a containerized environment for running applications. There are pre-built Docker images available for OpenFOAM. This can be a good option if you don't want to deal with installing Linux directly on your system.
Gas flow over a cylinder is a classic benchmark problem in computational fluid dynamics (CFD) and can be a good starting point for modelling floating steam. Here's a general overview of the steps involved:
**Geometry and Grid:**
* Define the geometry of the cylinder. This includes its radius and height.
* Create a computational mesh around the cylinder. This mesh discretizes the space into small cells where the governing equations are solved.
**Source Term:**
* For modeling steam plume, you'll need a source term representing the buoyancy force caused by the hot steam. This can be modeled as a momentum source in the vertical direction with a Gaussian distribution centered at the steam plume's origin. The standard deviation of the Gaussian will determine the plume's spread.
**Boundary Conditions:**
* Set appropriate boundary conditions for the gas flow. At the cylinder's surface, you'll typically have a no-slip condition, where the gas velocity matches the cylinder's velocity (which is usually zero for a stationary object). Other boundaries may have specified pressure or velocity conditions depending on the specific scenario.
**Solver:**
* This is where the CFD magic happens. You'll need a CFD solver to discretize and solve the governing equations of fluid mechanics (i.e., Navier-Stokes equations) for the gas flow around the cylinder. The solver will account for the source term representing the steam plume.
**Visualization:**
* Once you have the solution from the solver, you can visualize the velocity field to see how the gas flows around the cylinder and how it interacts with the steam plume.
**Challenges and Considerations:**
* Realistically modelling steam plume behaviour can be complex. Steam is a compressible gas, and its properties (like density) can vary with temperature. You might need to use more sophisticated CFD models that account for these variations.
* Turbulence is another factor to consider. If the flow velocities are high enough, turbulence can play a significant role in the steam plume's behavior. Modeling turbulence adds complexity to the CFD simulation.
**Software Options:**
* There are several open-source and commercial CFD software packages available. OpenFOAM and ANSYS Fluent are popular choices for industrial applications.
**Additional Tips:**
* Start with a simplified model to understand the basic flow behavior. You can gradually increase the complexity by incorporating turbulence or compressibility effects.
* Consider the computational cost of the simulation. Running high-fidelity CFD simulations can be expensive in terms of computational resources.
By following these steps and considering the challenges, you can develop a CFD model to simulate gas flow over a cylinder and gain insights into the behavior of a floating steam plume.
SU2, Ansys Fluent and Helyx-OS are three popular CFD software that have different features, advantages and disadvantages. Here is a brief summary of their main capabilities:
- SU2: SU2 is a free and open-source software that is designed for compressible flow applications. It has many convective numerical schemes, turbulence models, and an adjoint solver for shape optimization. It can also handle complex geometries, multiphysics problems, and parallel computing. However, it is not very well-known and may have less support and documentation than commercial software¹².
- Ansys Fluent: Ansys Fluent is a commercial software that can perform a wide range of simulations, including incompressible and compressible flows, multiphase flows, heat transfer, combustion, acoustics, and more. It has various solvers, numerical schemes, and turbulence models, as well as a user-friendly interface and a large user community. However, it is expensive and requires a license to use. It may also have limitations in parallel computing and meshing²⁴.
- Helyx-OS: Helyx-OS is a graphical user interface for OpenFOAM, which is another free and open-source software for CFD. It allows users to set up, run, and post-process OpenFOAM cases in a simpler and faster way. It can handle complex geometries, unstructured meshes, and parallel computing. However, it may have less features and capabilities than OpenFOAM itself, and it may not be compatible with the latest versions of OpenFOAM⁵ .
- SU2: SU2 can also perform unsteady simulations, such as harmonic balance and dual time-stepping methods. It has a Python-based framework for automatic differentiation, which enables gradient-based optimization and uncertainty quantification. It also has a modular structure that allows users to customize and extend the code¹².
- Ansys Fluent: Ansys Fluent can also perform mesh adaptation, moving and deforming meshes, and overset meshes. It has a comprehensive library of physical models, such as reacting flows, multiphase flows, porous media, radiation, and more. It also has a user-defined function feature that allows users to write their own code and link it to Fluent⁴ .
- Helyx-OS: Helyx-OS can also perform steady and transient simulations, as well as large eddy simulation and detached eddy simulation. It has a graphical interface for meshing, boundary conditions, solver settings, and post-processing. It also has a built-in mesh quality checker and a mesh conversion tool⁵ .
Source:
(1) Comparison between SU2 and Fluent - CFD Online. https://www.cfd-online.com/Forums/su2/221077-comparison-between-su2-fluent.html.
(2) Computational Fluid Dynamics Analyses of a Wing with Distributed .... https://mdpi-res.com/d_attachment/aerospace/aerospace-10-00064/article_deploy/aerospace-10-00064-v2.pdf?version=1674032673.
(3) Ansys Fluent vs SU2 [2023]: In-Depth Comparison Report. https://www3.technologyevaluation.com/solutioncomparison/61384/ansys-fluent/54099/su2.
(4) https://doi.org/10.3390/.
(5) Computational Fluid Dynamics Analyses of a Wing with Distributed ... - MDPI. https://www.mdpi.com/2226-4310/10/1/64.
Can you recommend some other CFD software?
Sure, I can recommend some other CFD software that you may find useful for your engineering projects. Here are some of them:
- COMSOL Multiphysics: COMSOL Multiphysics is a commercial software that can perform CFD simulations as well as other types of physics-based simulations, such as structural mechanics, electromagnetics, heat transfer, and more. It has a user-friendly interface that allows you to create and modify models using a graphical approach. It also has a powerful equation-based modeling feature that lets you define your own equations and boundary conditions. It supports various solvers, numerical methods, and meshing options. However, it is expensive and requires a license to use. It may also have limitations in parallel computing and scalability¹.
- OpenFOAM: OpenFOAM is a free and open-source software that can perform CFD simulations as well as other types of fluid dynamics simulations, such as multiphase flows, turbulence, combustion, acoustics, and more. It has a modular and flexible structure that allows you to customize and extend the code. It also has a large library of solvers, numerical schemes, and turbulence models. It supports complex geometries, unstructured meshes, and parallel computing. However, it has a steep learning curve and requires a good knowledge of programming and CFD. It may also have less support and documentation than commercial software².
- SimScale: SimScale is a cloud-based software that can perform CFD simulations as well as other types of engineering simulations, such as structural mechanics, thermodynamics, acoustics, and more. It has a web-based interface that allows you to access and run simulations from any device and location. It also has a collaborative platform that lets you share and review your projects with other users. It supports various solvers, numerical methods, and meshing options. However, it requires an internet connection and a subscription to use. It may also have limitations in data security and privacy³.
Source:
(1) 11 Best CFD Software Solutions to Boost Your Engineering Efficiency. https://geekflare.com/best-cfd-software/.
(2) OpenFOAM | Free CFD Software | The OpenFOAM Foundation. https://openfoam.org/.
(3) ANSYS Fluent vs. Other CFD Softwares - MR CFD. https://www.mr-cfd.com/ansys-fluent-vs-other-cfd-softwares/.
Are there any other open source CFD software ?
Yes, there are many other open source CFD software that you can use for your fluid dynamics simulations. Here are some of them, along with a brief description of their features and advantages:
- Elmer: Elmer is a multiphysical simulation software that can perform CFD simulations as well as other types of physics-based simulations, such as structural mechanics, electromagnetics, heat transfer, and more. It has a graphical user interface that allows you to create and modify models using a graphical approach. It also has a powerful equation-based modeling feature that lets you define your own equations and boundary conditions. It supports various solvers, numerical methods, and meshing options¹.
- FEATool Multiphysics: FEATool Multiphysics is a MATLAB and GNU Octave toolbox that can perform CFD simulations as well as other types of engineering simulations, such as structural mechanics, heat transfer, electromagnetics, and more. It has a user-friendly interface that allows you to set up, solve, and post-process models using a graphical or script-based approach. It also has a built-in interface for OpenFOAM, FEniCS, and SU2, which enables you to use these solvers within the FEATool environment².
- Code_Aster: Code_Aster is a finite element software that can perform CFD simulations as well as other types of mechanical simulations, such as solid mechanics, contact, fracture, fatigue, and more. It has a command-line interface that allows you to define and execute models using a text-based language. It also has a large library of physical models, such as turbulence, multiphase flows, combustion, and more. It supports complex geometries, adaptive mesh refinement, and parallel computing³.
- Code_Saturne: Code_Saturne is a finite volume software that can perform CFD simulations for various types of flows, such as incompressible, compressible, laminar, turbulent, reactive, and more. It has a graphical user interface that allows you to set up, run, and post-process models using a graphical approach. It also has a modular and flexible structure that allows you to customize and extend the code. It supports complex geometries, unstructured meshes, and parallel computing⁴.
I hope this helps you find the best open source CFD software for your needs. If you want to learn more, you can check my blog. Have a nice day! 😊
¹: [Elmer - CSC](https://www.csc.fi/web/elmer)
²: [FEATool Multiphysics - MATLAB FEA Physics Simulation Toolbox](https://www.featool.com/)
³: [Code_Aster - Wikipedia](https://en.wikipedia.org/wiki/Code_Aster)
⁴: [Code_Saturne - Wikipedia](https://en.wikipedia.org/wiki/Code_Saturne)
Source:
(1) OpenFOAM | Free CFD Software | The OpenFOAM Foundation. https://openfoam.org/.
(2) Open-Source CFD Software Packages: Good Enough and Free. https://www.digitalengineering247.com/article/open-source-cfd-software-packages-good-enough-and-free.
(3) ANSYS Fluent Alternatives and Similar Software | AlternativeTo. https://alternativeto.net/software/ansys-fluent/.
(4) Free ANSYS Fluent Alternatives | AlternativeTo. https://alternativeto.net/software/ansys-fluent/?license=free.
(5) OpenFOAM Alternatives and Similar Software | AlternativeTo. https://alternativeto.net/software/openfoam/.
