Tesla's Cybertruck Aerodynamics Do Flow Smoothly, as per a CFD Analysis
Tesla's recently unveiled Cybertruck has sparked people's interest around the world. Some believe it's the next best thing since sliced bread, whereas others think it's a big step back in car design.
However, the Cybertruck is now among us, so we may as well get on board with it.
Moving away from personal opinions, the truck's boxy shape has raised a few eyebrows as people question its advertised ranges, wondering if its bizarre shape will constantly have the car fighting against air and vortexes.
So, as one does, an aerospace engineer decided to check for himself and ran the Cybertruck through a CFD simulation (computational fluid dynamics — a computer version of a wind tunnel). Here's what he found out.
What did the aerospace engineer discover?
Firstly, it must be pointed out that Tesla hasn't yet brought up the topic of its Cybertruck's aerodynamics, and didn't breach the subject of drag coefficient. However, the experienced team at Tesla surely knew what they were doing when designing the truck, and it will most likely deliver on its performance promises.
That said, it's always good to know more. So, aerospace engineer Justin Martin took it upon himself to find out exactly how the air behaves when it hits the stainless steel beast.
Martin built a model of the truck from images and videos he found and then ran the truck through a CFD simulation. Martin spent a good 24 hours researching each and every angle of the truck ahead of the simulation.
One note to point out is that Martin decided not to share a coefficient of drag number as his assumptions of the wheels and fenders could have affected his results.
View this post on Instagram
Well, no one else did it so I did. Here is the #CyberTruck in CFD. What intrigues me is how well this works. While it may occur to be happenstance that the aero turns out quite well, I believe this was actually the result of very clever design. Ease of manufacturing in flat panels, significant use of triangulated body parts, etc. I won't quote a drag coefficient, as I dont want to put words in anyone's mouth, but I will place money on it being much lower than most sports cars, and any truck period. Further, I believe the vortex shed over the bed walls helps act to "seal the bed" when the cover is open. I havent modeled the open bed yet, but it sure seems promising. Further, it appears the front end is designed to almost entirely blank out / shield the wheel well.... The cad file is dimensionally correct, all angles and curves are as close as possible. There are some uncertainties such as fenders and wheel well air-exhaust etc. Lastly, at 65mph the local velocity over the roof "peak" is 88mph. Is this the ultimate Elon Easter Egg? @tesla #Tesla #TeslaTruck #CFD @elon
All in all, it looks like the Cybertruck's vault works well and maintains an attached flow as it passes over the top of the car. A little rough point can be seen at the top of the car where airflow goes up to 141 kph (88 mph) when the car is doing 104 kph (65 mph), but that's nothing new.
Martin pointed out to us at Interesting Engineering that it's ironic that such a Delorean 'Back-To-The-Future' looking truck produced this local flow at such highway speeds.
The yellow line at the back of the car shows that this leads to a detached airflow, but most of that is due to the air blowing off of the truck's huge windshield.
Almost everything sheds a vortex, as Martin pointed out to us, however, he found it interesting how it does so over the bedsides of the Cybertruck. His belief is that it perhaps helps to reattach airflow after the peak.
The biggest point of turbulence is at the back of the truck, behind the closed truck bed. This is quite normal in most trucks, though.
The fenders and wheels remain a question mark, as Martin wasn't able to represent them properly through his research.
Martin is the first to admit his findings aren't perfect, but they're a great first draft. Moreover, this model helps shed light on the matter and shows that the truck may be more aerodynamic than skeptics thought.
Here are some more up-close images of Martin's CFD simulation: