The Transparent Car

https://youtu.be/jZBsOud4O9Q

In the Forward braking quadrant, power output is -ve, which means the battery is charged, but the -ve torque can occur when the battery is reversed. So, instead of charging the battery, energy is dissipated by the internal resistance of the battery. This is called plugging braking. https://www.electrical4u.com/what-is-braking-types-of-braking-regenerative-plugging-dynamic-braking/ To enable charging, you need to have the back emf to be larger than the battery. The speed is faster than the speed that the battery provides, which can occur when going downhill. This is true for DC motors. For BLDC, you can reverse the phase of the controller to brake the motor and under simulation, some regeneration is possible, but actual measurements of power input and output only showed a maximum of 30% regeneration. https://www.radiocontrolinfo.com/does-an-rc-motor-and-esc-provide-regenerative-braking/ https://youtu.be/znlo8-ZzStQ The paper below shows thar regen occurs during braking but n...

https://youtu.be/b0J2JeSjOLg

 "The ‘Automotive Transformation Fund: Expression of Interest’ assessment process has now concluded. With regret your application has been deemed out of scope and ineligible for funding through the Automotive Transformation Fund. ATF is not funding R&D activity for product or process development which is at prototype or early proof of concept stage. Please continue to review other funding opportunities available via the Innovate UK website." You will be surprised that despite it being called Innovate, it does not support any innovation, only proven concepts. "proof of concept" is not allowed.  From wikipedia:  "Proof of concept (POC), also known as proof of principle , is a realization of a certain method or idea in order to demonstrate its feasibility , [1] or a demonstration in principle with the aim of verifying that some concept or theory has practical potential. A proof of concept is usually small and may or may not be complete."  ...

Based on actual US Navy pilots' close observations, verified by radar and infrared sensors, a UFO or UAP, really exist, and one of them is a black cube surrounded by a transparent sphere. So do not under rate designs that use the simplest shapes. Advanced alen crafts use them.

 From conservation of momentum, we can assume that F*dt = m*v dt is just an arbitrary time interval but it turned out that 1 second is a good estimate for actual deformation of a car during a crash based on comparisons of videos of car crashes. https://www.arcjournals.org/pdfs/ijmsme/v3-i1/1.pdf The better approach should just be to check the deformation in the direction of travel and force applied in front. The back is assumed to be constrained during the FEM analysis. The FEM was done using Calculix solver in FreeCAD running on a Mac. Unlike the Windows version, gmsh does not work so Netgen was used. When force applied in front is 80,000 N, the x direction displacement is 0.25 m, so the energy absorved is 20,000 J. For a mass of 1000 kg, using kinertic energy equation, the velocity of travel is sq. root 40, 6.3 m/s. Maximum von Mises stress is 96 MPa located in front. We can assume that an acrylic body can crash with a speed of 5 m/s without any major damage to its body. The gre...

  https://grabcad.com/library/freecad-fem-of-a-transparent-car-1  

 For the past few weeks, I had struggled with free CFD tools to calculate the Coefficient of Drag of a few cars that have well known measured CD. Tesla Model 3, Shulich I solar car, Pac Car 2. I also did a CFD simulation of the Solar Car 2 and my Transparent SUV. Installation FreeCAD, Paraview, gmsh, cfmesh for Windows 10. These are the best so far in 2022. I tried a few years ago the online openfoam based such as Simwork, they are limited so as to be impractical if you want to run for free. Once you have installed FreeCAD, install the addon, plot, CFDoF and FEM. The easiest version is for windows. OSX is more difficult but basic FreeCAD will work. Installin openfoam is just too difficult. I failed to install the docker and another native OSX installers. When installing CFDoF, no need to install openfoam using other methods other than that shown in the Edit\Preferences\CFDoF. If they failed to install, look at the link and search for the latest version and download separately. The ...

JJust scale the frontal direction to a very small figure. Then meaasure its area using 3d print tools.

this is the easiest way to calculate frontal area of an object. This method uses Paraview. Another method uses Blender but it was too complicated. Paraview method is eaasier but not completely accurate because it just reduces the thickness to a very low value.

This is how you convert STL into parts in FreeCAD. After you have converted into a part, only then can you use CFDoF to do CFD simulation by combining the tunnel with the object to be simulated. The command is in Part, Create shape from mesh. stl is a mesh format. shape is the solid or part format.

CFDoF does not work with many STL files. Even those from 3d printable files such as Thingiverse. This video may help in cleaning up files to be used for CFD.

https://youtu.be/J944HOj_4b0 This is a better way to calculate aerodynamic forces. He does not multiply by density and does not use vectors. Unfortunately, using cell data resulted in errors. Use point data.

  https://formulacareers.com/wp-content/uploads/2020/08/OpenFOAM_slides_week1_final.pdf A very good source for openfoam tutotial instruction. Actually the installation always come with the sources and settings for the tutorials. Getometry files: C:\Program Files\ESI-OpenCFD\OpenFOAM\v2012\msys64\home\ofuser\OpenFOAM\OpenFOAM-v2012\tutorials\resources\geometry Settings directory:  C:\Program Files\ESI-OpenCFD\OpenFOAM\v2012\msys64\home\ofuser\OpenFOAM\OpenFOAM-v2012\tutorials\incompressible\simpleFoam\motorBike  This version of OpenFOAM is installed by the CFDof workbench in FreeCAD 0.19 in its preferences. I tested the openfoam commands in Ubuntu in Windows 10.