CFD stands for Computational Fluid Dynamics. It's a branch of fluid mechanics that uses numerical methods and algorithms to solve and analyze problems involving fluid flows. CFD is commonly used in engineering and physics to simulate the behavior of gases and liquids and their interactions with surfaces.

Applications of CFD:

Aerospace Engineering: Simulating airflow over aircraft designs to optimize aerodynamics.

Automotive Industry: Improving vehicle performance by analyzing drag, airflow, and cooling systems.

Architecture: Studying wind loads on buildings and the distribution of HVAC systems.

Energy Sector: Modeling flows in pipelines, turbines, and nuclear reactors.

Biomedical Applications: Simulating blood flow in arteries for medical research.

It involves solving complex equations like the Navier-Stokes equations, which describe the motion of fluid substances.

https://www.cfdsupport.com/cae-open-source-software.html

Each piece of software has its pros and cons. Usage of any of them depends on the particular project needs and many other circumstances (Physics, resources, skills, experience, …).

Please contact us if you find new open-source software to complete this list or broken link or any inaccuracy. We’ll be happy to fix it.

May you have any questions, don’t hesitate to get in touch with us.

Best Regards,

Team CFD SUPPORT

Hi! I'm a beginner CFD user, and I've encountered a strange bug with my mesh. When I reduce the firstLayerThickness to a smaller value, the mesh stops working. The layer doesn't generate properly, and I get an error saying my refineBox isn't inside my blockMesh, which is incorrect.

TCAE-Lite is designed for those with limited budgets.

Over 50 man-years of consistent development on top of open-source condensed in unlimited software at the cost of a daily cup of coffee. 

https://www.cfdsupport.com/tcae-lite.html

hashtag#CFD hashtag#Simulation hashtag#FluidDynamics hashtag#FlowVisualization

I am looking to simulate the power output of an in pipe axial turbine, I don't have any experience in CFD simulations and I've decided to brake down the project into 3 parts, first I am going to simulate just the pipe in which the turbine is going to be housed, then a static state with the turbine in the pipe, and finally setup the rotation of the turbine.

I've made a quick 3D model of the pipe and I tried copying the setup from the pipe example, I ran into a problem where the mesher consumes all the available RAM on the computer and locks it up, I assume the STL mesh has a hole somewhere but I couldn't find it, I've had issues before with glitches in STL meshes made in Rhinoceros 3D, the modeling program I used, so I decided to recreate the pipe example with the STLs from the example, and that meshed successfully, but I got an error in the TCFD part "TCFD calculation failed. Please consult the chapter 'Rescue list' in the TCAE Manual for possible reasons of the failure.", I couldn't find the Rescue list chapter in the manual online.

Also the TCAE Output gives this error:
"Application decomposePar failed.
For detailed information check error log at: "C:\Users\Name\Desktop\CFD Test\CFD_test\simulationRun1\TCFD\logRun\solve-err-decomposePar-stationary-1.log"".

And in that log file is:
"--> FOAM FATAL IO ERROR:
Cannot find patchField entry for Co1_pipe-wall_wall

file: C:/Users/Name/Desktop/CFD Test/CFD_test/simulationRun1/TCFD/stationary/0/nut/boundaryField from line 32 to line 54.

    From function void Foam::GeometricField<Type, PatchField, GeoMesh>::Boundary::readField(const Foam::DimensionedField<TypeR, GeoMesh>&, const Foam::dictionary&) [with Type = double; PatchField = Foam::fvPatchField; GeoMesh = Foam::volMesh]
    in file /opt/OpenFOAM-dev/src/OpenFOAM/lnInclude/GeometricBoundaryField.C at line 184.

FOAM exiting"

Attached is a rough diagram of how will the setup work.

I don't have an idea what to try next, and would be thankful for any assistance.

This is more like an open question than a fully formed topic with both question and answer.

I am running an incompressible laminar flow simulation with the pimpleFoam solver. It has two openings on one side (n1 and n2) and one on the other (n3). I have set up the pressure boundary conditions so that the flow is driven primarily by the pressure applied at n3. The flow should be changing direction halfway. Realistically, the total volume passing through an opening should be the same for the two flow direction. Yet, when I sum over the patch flow rates (postProcessing function) of the two flow directions and compare them, they are different. What could be the potential reason(s) for this phenomenon?

Following is the pressure boundary condition I set up:

/*--------------------------------*- C++ -*----------------------------------*\
  =========                 |
  \\      /  F ield         | OpenFOAM: The Open Source CFD Toolbox
   \\    /   O peration     | Website:  https://openfoam.org
    \\  /    A nd           | Version:  10
     \\/     M anipulation  |
\*---------------------------------------------------------------------------*/

FoamFile
{
    version     2.0;
    format      ascii;
    class       volScalarField;
    object      p;
}
// * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * //

dimensions      [0 2 -2 0 0 0 0];

internalField   uniform 0;

boundaryField
{
    n1
	{
		type            totalPressure;
		p0              uniform 0;  // Reference total pressure (e.g., atmospheric pressure in Pascals)
		U               U;               // Velocity field name
		phi             phi;             // Flux field name
		rho             none;            // Density, use 'none' for incompressible flow
		psi             none;            // Compressibility, use 'none' for incompressible flow
		gamma           1;               // For incompressible flow, use 1
	}

	n2
	{
		type            totalPressure;
		p0              uniform 0;  // Reference total pressure
		U               U;
		phi             phi;
		rho             none;
		psi             none;
		gamma           1;
	}


    n3
    {
		type		uniformTotalPressure;
	p0
	{
		type		sine;
		frequency	0.3333333333333333;
		amplitude	-50.0;
		level		0;
	}


    }
    walls
    {
        type            zeroGradient;
    }

    defaultFaces
    {
        type            empty;
    }

}

// ************************************************************************* //



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   CFDSUPPORT has initiated a benchmark that tests and compares the speed of various processors, providing crucial insights for engineering simulations. 

📊🖥️ Not just that, we're inviting academicians, professionals, and enthusiasts like YOU to contribute! Yes, ALL participants are welcome! 🙌
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For a comprehensive understanding, do check out our full case study 📄 (download option available) at https://www.cfdsupport.com/motorbike-cpu-processor-benchmark.html
Help us create a more informed academic and professional community. Let's benchmark for a better tomorrow! 💪🌐
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Hello, I am very new to CFD and simulations, I am trying to simulate the power output of a kaplan hydro turbine. I have made the geometry, but when I try to mesh it, after 15 minutes it fails. Is there any function in TCAE that I can use to check the mesh, I think it might not be water tight, but I don't know where. Also, the setup check passes without errors.

If you need any more information, please let me know.

Thank you in advance.

Hello, I tried to run the benchmarks case DJI9450 that I downloaded from CFD SUPPORT. But the  CFD calculation failed after 100 hours running and it showns that "Application redDyMsolver failed" . And there was nothing in the error log. I haven't change anything except the number of processor. Would it be OK if I run it again?

Thanks for your help.

Hello everyone,


I have questions about the calculation of circumferential angles circA by TCAE.


I have understood that, if a surface is oriented in the radial direction, circA on this surface will be the angle between the tangent and the velocity in the radial/tangential plane. According to graphical representation of the manual, circA shoud be positiv when the projection of the velocity in the radial/tangential plane points out (of the cylinder in the picture), and negativ when it points in.


Let's imagine that we are on a surface radially oriented where some back flow occurs and that the absolute velocity has a circA > 90° when there is no back-flow. In most of the cells of the surface, circA points out of the cylinder (90° < circA < 180°), but when back-flow occurs, circA points in the cylinder (-180° < circA < -90°). Thus, there are positiv and negativ values of circA at the same time, isn't it ? Therefore, because the circA are either > 90° or < -90°, in the in the interfaces-final.csv file in simulationRun1/TCFD/stationary/postProcessing/surfaceName/0/ folder, it seems to me that surface averaged value of circA is distorted.

I had this reflection because I find particularly high values of circA on some surfaces of my simulations.

Could someone confirm my interpretation ? Or explain me why it isn't true ?

Besides, does someone know how to visualize circA angles on Paraview after a calculation ?


Thanks in advance !


Zacharie

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I am reconstructing the case of the cyclone separator using the Euler-Euler approach given in this link. Unfortunately, many of the images and tables are corrupted, making the process quite difficult.

I have some specific questions about the Allrun file found here, especially regarding the following fragment:

echo "Modifiing and adding files in/to 0 dir..."

cd 0

rm -rv uniform

cp -v U U.water

mv -v U U.particles

rm -v nut

mv -v epsilon epsilon.water

mv -v k k.water

mv -v p p_rgh

cp -v ../0.euler/nut.particles .

cp -v ../0.euler/nut.water .

cp -v ../0.euler/T.water .

cp -v ../0.euler/T.particles .

cp -v ../0.euler/Theta.particles .

cp -v ../0.euler/alphat.particles .

cp -v ../0.euler/alpha.particles .

cp -v ../0.euler/alphat.water .

cp -v ../0.euler/alpha.water .

cp -v ../0.euler/p .

cd ..

echo "                                     ...done"

1. Why is the p field renamed to p_rgh, considering that p in simpleFoam is in Pressure/density units, and p_rgh is in Pressure units?
2. Why is nut removed and reinitialized when simpleFoam handles it?

Other questions regarding the simulation are:

Which is the drag model more adequated for solid-fluid simulation?

I would also like to know if anyone has the case folder available.

Thank you for your help.