Running a single CFD simulation rarely provides enough information to find a good hydraulic or aerodynamic design of a component. In many cases the poor engineer has to wrestle an awfully long list of design parameters into a state-of-the-art shape. Luckily, OpenFOAM and DAKOTA together provide an almost ready-to-use solution just for that: Sensitivity analysis(long […]
I’m building a wind turbine and as you might imagine, the blades are Ye Royale Paine In Me Buttocks. Too big for a CNC, too exposed for a 3D print, too complicated to be made by hand. I decided to make blades from pipes. This simplifies the build but now how do I know how
The Old-Fashioned blockMesh BlockMesh is the weapon of choice for directly generating rather simple meshes of channels, pipes, 2D-stuff etc. Those are mostly internal flows. With external flows, life gets tough much quicker. Consider a very simple case of a 3D flow past a cube. You now need this many blocks: But the cube itself
All OpenFOAM tutorials have Allrun and Allclean scripts which call some mysterious RunFunctions from even more mysterious sources. The most mysterious thing of all this is how poorly those are documented. Since those are not a big deal, I decided to jot down some remarks so a newcomer can tell what they are for. The
IMPORTANT! classy_blocks have been massively improved but this article hasn’t. Please refer to readme in repository for most up-to-date information and examples. blockMesh: pros and cons blockMesh is a great tool for creating simple and quick meshes. It also creates structured meshes and offers total control over its cells, which snappyHexMesh (and many other) doesn’t.
I am not going to share my negative opinion on visual aspects of design of this vehicle (although I could be very verbose) but there are some technical issues I need to clarify. There are statements in style of “Tesla Cybertruck could be insanely aerodynamic” or “Tesla’s Cybertruck Aerodynamics Do Flow Smoothly” or even nonsense
Context If you’re creating a multiregion mesh and you found this article you probably already know what SALOME , OpenFOAM, snappyHexMesh and chtMultiRegionFoam mean. In case you dont’ here’s a quick explanation: OpenFOAM is your favourite open-source CFD package, chtMultiRegionFoam is the OpenFOAM solver for conjugate heat transfer simulations, conjugate heat transfer analysis calculates heat
Practical Background Our intuition will tell us that sharp or rounded objects will cause less drag when moving through fluid. Slightly less intuitive is the fact that changing the rear part will reduce drag even more than changing the front. So why is it that on cars and trucks, all drag-reducing effort is being put
