CFD_FOAM

🔴 All you need to learn OpenFOAM 1- OpenFOAM book [in Persian] 2- OpenFOAM video tutorials [in Persian] 3- OpenFOAM tutorials on github 4- OpenFOAM tutorials and search in the channel for extra tutorial and learning materials

🔴 Search deeply through the codes https://sourcegraph.com/search

🔴 a tool that reconstruct high-detailed 3D city geometries for microscale urban flow simulations. https://github.com/tudelft3d/City4CFD

🔴 the signed distance function (SDF) of geometry corrupted by holes, noise, or self-intersections. https://nzfeng.github.io/research/SignedHeatMethod/

🔴A 5-Minute CMake Survival Guide: https://journal.hexmos.com/cmake-survial-guide/

🔴 CFD with python Prof. Lorena Barba https://github.com/barbagroup/CFDPython 🔴 Lecture videos: https://www.youtube.com/playlist?list=PL30F4C5ABCE62CB61 🔴Additional CFD examples with python https://drzgan.github.io/Python_CFD/intro.html 🔴CFD course by Prof. Suman Chakraborty https://www.youtube.com/playlist?list=PLbRMhDVUMngcFmWiK1YBhAbsYo8mYvPKJ 🔴CFD on HPC https://arc4cfd.github.io/about/

🔴 learn to visualize your dataset with PyVista link: https://tutorial.pyvista.org/

🔴 create boundary patch from non-closed STL using paraview [from here]: 1. Load the STL model. 2. Activate the feature edges filter to isolate boundary edges only (deactivate other features extraction). 3. Apply the connectivity filter to assign points into regions. 4. Utilize the threshold filter to isolate regions. 5. Employ the Delaunay2D filter with the "Best fitting plane" option activated. 6. Export the boundary patch in STL format.

🔴 recommendation: using leastSquare for gradient schemes on unstructure grid in OpenFOAM

gradSchemes { default none; grad(U) leastSquares; }

read more [here]

🔴 Checkout our latest paper: Numerical investigation of bubble dynamics and flow boiling heat transfer in cylindrical micro-pin-fin heat exchangers [link]

🔴 checkout our recent paper: Drop rebounding on heated micro-textured surfaces [link]

🔴 A Modified Overset Method in OpenFOAM for Simultaneous Motion and Deformation [link] #overset #dynamicMesh

🔴 Post processing tip - Average over selected cut surface

z0.2 { type surfaceFieldValue;//faceSource; functionObjectLibs ("libfieldFunctionObjects.so"); enabled true; writeControl outputTime; // Output to log&file (true) or to file only log true; writeFields true; //// Type of source: patch/faceZone/sampledSurface select sampledSurface; surfaceFormat vtk; fields ( UMean.particles alphaMean.particles ); sampledSurfaceDict { type cuttingPlane; planeType pointAndNormal; pointAndNormalDict { basePoint (0 0 0.2); normalVector (0 0 1); } source cells; // sample cells or boundaryFaces interpolate true; } // Operation: areaAverage/sum/weightedAverage ... operation areaAverage; }

🔴 High-resolution Structure-preserving Convection Schemes github link: https://github.com/advanCFD/libROUNDSchemes/

🔴 hybrid Central solvers based on central-upwind schemes of Kurganov and Tadmor including vofTwoPhaseCentralFoam github: https://github.com/unicfdlab/hybridCentralSolvers

🔴 How to use GMESH to create grid for OpenFOAM link: https://youtu.be/A-gNbBZCelc?si=n2g_3FwHUd2BtsHX

🔴 Some points on grid quality 1️⃣ Non-orthogonality, skewness, and uniformity do not affect the accuracy of source terms. The accuracy depends only on the size of the cells and the error tends to zero with mesh refinement. This means that when the source terms behave in an obscure manner, it makes sense to refine the mesh or revise their linearization practice. 2️⃣ Non-orthogonality does not affect accuracy on divergence, gradient, and source terms and is not the most important quality metric for convection-dominated flows. It influences the calculation of the surface-normal gradient (snGrad) the Laplacian terms. Therefore, It is an important measure in the viscous part of the boundary layer 3️⃣ Skewness and uniformity affect the accuracy of divergence and gradient terms. It is important to note that this is only the case in regions where the solution is not uniform! In practice, this means that the mesh shall be of high quality where the gradients are significant e.g. in shear layers, and jets, where the solution exhibits rapid variation! 4️⃣ Skewness does not play a role when using the upwind scheme. This scheme is diffusive and is not the best choice when accurate solutions are desired. 5️⃣ Cell types with face pairs shall be preferred because they provide better accuracy for the same number of cells. Therefor, Quadrilateral cells in 2D and hexahedral cells in 3D are the best cell shapes 6️⃣ Hex-dominant meshes with split-hexes are a good compromise between accuracy and simplifying the process of mesh generation. These meshes performed better than hexagons for cases where the bulk of the flow is aligned with mesh. 7️⃣ Meshes consisting of triangles and tetrahedra are the least accurate mesh types. They are used because the process can be automated much easier than for other mesh types. However, they often require an order of magnitude more cells which makes them greedy for computational resources. 🔗links: [1, 2, 3, 4]