The Transparent Car

  How To Keep the Courant Number Below 1? Created On February 10, 2020 by Theresa https://www.simscale.com/knowledge-base/what-is-a-courant-number/   The intention of this article is to define what a Courant number is and to give a best practice of how to set your mesh and time step in case you have problems with the Courant number. If you want to have more details you should read this article . Definition The Courant–Friedrichs–Lewy or CFL condition expresses that the distance that any information travels during the time step length within the mesh must be lower than the distance between mesh elements. In other words, information from a given cell or mesh element must propagate only to its immediate neighbors. The derivation of the CFL condition leads to the formula for Courant number and is given by:   C = u Δ t Δ x C = u Δ t Δ x where C is Courant number,

https://www.cfd-online.com/Forums/fluent/207943-determining-ideal-mesh-size.html Co = v * dt / dx, where v is your maximum velocity in the domain, dt is your time step (defined in solver), and dx is your typical mesh size.

A good tutorial on how to analyse Openfoam data using Paraview.

I find watching this video boring but the links are userful and the linked tutorial very helpful. Better than reading the instructiions in the FreeCAD Addon installation comments for CFDof. http://www.opensim.co.za/training.html   The tutorial that is useful in doing CFD for car is the one below: https://github.com/opensimsa/opensim/raw/master/Documentation/CFD/UAV2/CFD%20Tutorial%204%20-%20External%20Aerodynamics%20of%20a%20UAV.pdf   WINDOWS: ● https://www.freecadweb.org/wiki/Download ● Install CfdOF from Tools | Addon manager ● Go to Edit | Preferences | CFD to check and install dependencies   Of special note: I install the older version of Paraview as shown in the FreeCAD preferences. I downloaded cfmesh and HiSA from sourceforge. No need to look for binaries. It appears as though the master file  zipped file can be installed by FreeCAD.   cfMesh downloaded to C:\Users\othma\AppData\Local\Temp\tmpwg568v1r.zip Installing cfMesh... Install completed Downloading HiSA, please wait...

Why Tank Turn has been delayed The automaker cares about safety, and while the R1T has a lot of  safety features , Rivian wanted to be sure that Tank Turn was safe to use, according to MotorTrend. Essentially, due to the laws of physics, Rivian needs to do a lot of extra programming to make Tank Turn safe. For example, without any safety precautions, the moment Tank Turn is activated, the wheels will lose traction.  If the Rivian is on an incline, then without traction, the truck will slide towards that direction. That’s not a good thing, so Rivian’s engineers need to program a safeguard against this scenario. Another issue that Rivian’s engineers will have to solve is speed. That’s because, in order to use Tank Turn, the wheels will have to go very fast. This could scare inexperienced drivers and cause them to lose control, and Rivian will need a safeguard.  So, for those reasons and more, Tank Turn has been delayed. Unfortunately, MotorTrend said that there’s no timeline on when Tank

https://youtu.be/y5qLYCn4qJw

Take note that this is in smooth roads. High Pressures mean the tires do not absorb the shocks any more. All of it goes to the shock absorbers. And this article is based on real experiences from drivers. Why don't we try on our cars?  Based on cyclists, high tyre pressures do not necessarily result in energy savings because the energy is lost on the cyclists who need to absorb the shocks. It is true that high tyre Pressures, up to 100 psi will result in lower tyre rolling resistance but it means a harsher ride that is not enjoyable. Based on real tests on rough roads, high tyre Pressures can consume more energy compared to Pressures above the minimum recommended tyre Pressures. Bicycle travel more on rougher roads because of their poor shock absorption and sizes. 

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https://www.iea.org/reports/fuel-consumption-of-cars-and-vans Tracking report — November 2021 Authors and contributors Cite Share