by saturn5k on 8/6/22, 8:17 PM
For engine nerds, you should check out Automation - The Car Company Tycoon Game [1]. It is basically a car builder simulator where you go through every aspect of developing a car - chassis design, suspension, engine..
I spent hours tuning and building exotic engines. 6 liter turbo inline 3? 1 liter NA V12? Only your imagination is the limit.
[1] https://www.youtube.com/watch?v=xQpfvliszx4
Bonus: You can export your vehicles directly in BeamNG.drive and test them on the track.
by Scene_Cast2 on 8/6/22, 2:58 PM
Sounds amazing, would love for something like this for racing sims (CPUs these days have more cores than good uses for those cores...)
For the gotchas - I'd guess that the exhaust manifolds would make a huge difference in terms of sound, and they seem hard to simulate. For example, engineers tune the individual per-cylinder exhaust distance - this way, the exhaust fumes from each individual cylinder align nicely once the exhaust from each cylinder merge into the final exhaust pipe. Otherwise, if, for example, the firing pattern is 1-5-..., then the air from cylinder 1 might arrive to the exhaust pipe at the same time as air from cylinder 5, given high RPMs and limited speed of sound.
And the fluid dynamics of the cylinders are something that is extremely critical to modern cars, too. And I'd guess that this is where things like misfires can be simulated.
Disclaimer - this is all based on my highly unsophisticated mental model,
by bitwize on 8/6/22, 2:50 PM
The thing that got me into computing was watching an engine simulation my dad, a mechanical engineer, wrote in BASIC. He wanted to get some numbers on the mechanical advantages of various crank designs, so he only simulated the piston, crank, and crankshaft. And it chugged at about 1 fps on a TRS-80 Model II. But still, seeing that piston and crank arm move made me realize computers are capable of truly wondrous things.
And if that was the Lv 1, this is the Lv 99.
by modeless on 8/6/22, 4:04 PM
80,000 Hz rigid body simulation! That's amazing. Seems like the only output of the simulation that's used in sound generation is the graph of exhaust pressure. He's adding white noise to the output. I wonder if it would be possible to replace the white noise by reading the vibrations of the various rigid bodies directly out of the simulation.
by teddyh on 8/6/22, 8:16 PM
>
The code is open source on my GitHub, the link to that is in the descriptionDescription:
> Engine Simulator Codebase [Temporarily Private]
My most generous guess is that he got hit by a patent claim. I can’t think of any other reasonable reason for him to take back the code but keep the video up.
by nabla9 on 8/6/22, 4:14 PM
Car manufacturers might buy this for their EV's when they want their car make engine sounds.
by freemint on 8/6/22, 5:21 PM
I wonder that time integrator is used for what must be a DAE system and if a better integrator could cut those numbers of step required down by a lot.
by _fat_santa on 8/6/22, 2:21 PM
That's so cool. The guy made the repo private but I hope he makes it public again. It would be really interesting to see the code behind this. And looking at the other repos, I would bet its written in C++
by buescher on 8/6/22, 3:45 PM
That's very impressive. I hope he writes it up. I'd like to see the bibliography.
by zbird on 8/6/22, 11:24 PM
I think it would be interesting to simulate the audio of a fuel engine in EVs and be able to customize the output. Otherwise they sound a bit too boring.
by mandeepj on 8/6/22, 6:09 PM
Great job. If my car had that instrument panel - and I'd love to have it - then it'd look like a cockpit :-). Amazing stuff.
by zbird on 8/6/22, 11:17 PM
Very nice work, need more posts like this.
by jmpman on 8/6/22, 3:08 PM
Quite incredible. I’d like to see engine vibration in the X,Y,Z axis, to optimize engines for a quadcopter APU.
by dark-star on 8/6/22, 6:38 PM
anyone grabbed the code before the repo went private? I'd really like to play around with this a bit :)
by Cupertino95014 on 8/6/22, 3:50 PM
Maybe someone can find this YT video: it was a guy on the back of a Vespa or some small scooter, carrying a boombox that made the sound of a giant Harley.