Pointy roof for aerodynamics?

[tpoltron]

The only thing that grates on me about the Cybertruck design is the single pointy cab-forward roof peak. At first I wondered if that was just a stylish way to fit cowboy hats but then, more seriously, if it’s a close enough approximation to a teardrop to actually make it much more aerodynamic than a traditional pickup truck? It does really remind me of a F117 Stealth Fighter jet. I’d love some aerodynamics engineers to weigh in.

 

[pdx_m3s]

The roof point will create flow separation, which is detrimental to efficiency, as it increases drag. How much is hard to say. The long sloped rear half of the truck will help, but aerodynamics were certainly not a priority with this design. This is also evident with the wheel/tire placement (they protrude a lot), fender flares, and inset side windows.

 

[UCF3]

This has been discussed several times. Do a search for deeper stats

 

[Saghost]

Motortrend wrote a paragraph about that:

But the aerodynamics of that peaky profile?

It almost looks like a deliberate, suicidal attempt to trigger boundary separation—a potential drag-raising catastrophe for limited-energy EVs. And an odd 180 turn from the Model X and Y, which have such delicately arched profiles precisely to avoid drag-raising trip wires like this.

Tesla might have erased the problem with active suction to bend the boundary-layer downward just aft of that peak. Gordon Murray's McLaren F1 used this trick, and SpaceX has plenty of expertise in active measures to manipulate airflow around its re-entering Falcon 9 first stages. However, with the bed cover deployed, the angle of its vast descending surface is evidently shallow enough for the flow to naturally reattach. The benefit being that it harvests a useful fraction of the air pressure that blocky, open-bed trucks almost entirely forfeit. Actually, the tougher aerodynamic trick has been coaxing the temperamental flow around those sharp A-pillars.

How Tesla's Cybertruck Turns Car Engineering Norms Upside-Down - Motor Trend

Apparently the breakover is shallow enough it doesn't really trip the airflow.

 

[Saghost]

The roof point will create flow separation, which is detrimental to efficiency, as it increases drag. How much is hard to say. The long sloped rear half of the truck will help, but aerodynamics were certainly not a priority with this design. This is also evident with the wheel/tire placement (they protrude a lot), fender flares, and inset side windows.

I agree with most of what you said. But Aerodynamics certainly was *a* priority - hence the splitter nose and very steeply raked profile and retracting door handles.

As you note, they were willing to compromise on it for other aspects in places - it isn't the only priority - but it certainly is a driving factor for the design, and I'm sure the Cybertruck slips through the air more easily than either your average modern pickup or any of the renderings I saw before the release, if likely not quite as easily as say a Model X of similar size..

 

[tpoltron]

Well here's an answer to my question:
Are the boxy Tesla Cybertruck's aerodynamics any good? An engineer found out - Electrek