Generally (simplified), the steps involved in the CFD process are summarized in the flowchart below:
Figure 1.11. General (simplified) CFD workflow
In common modern CFD packages, the geometry can be easily imported from Computer-Aided Design (CAD) software, such as Solidworks, Autodesk Inventor/Fusion 360, Catia, or an open-source modeler such as Blender with various extensions depending on the software’s compatibility.
For more traditional CFD packages, in some cases that need high-quality mesh, the geometry is sometimes constructed manually while creating the mesh, ensuring the consistency of the mesh structure. This is sometimes only limited to simple and primitive geometries such as blocks or spheres.
The next step is meshing/griding, a process of converting continuous geometry (1D/2D/3D) into discrete form, in which we solve the equation within each discrete element. This process can be done automatically or manually, depending on the software package; sometimes, we use a different software package or brand only for meshing and then import it to the solver with the other package/brand.
After the mesh is set up, the following process is to solve the discrete equations inside each discrete mesh element, which stores the resulting data such as velocity, pressure, temperature, etc. Each software package sometimes has different capabilities and limitations for the solver; for example, some solvers can only solve incompressible flow or have no heat transfer. So, engineers should carefully read the solver they are using based on the physical phenomena they are facing.
To interpret the result, the solution can be plotted as curves or 3D-colored contours. This process is called post-processing. Again, some software sometimes uses a different package/brand to do the post-processing. Or, a popular open-source post-processing tool such as paraView can sometimes be used for various extensions.
Figure 1.12. Post-Processing using ParaView
Leave a Reply