Pretty much how we do things in Australia!
Wait. Where does the cover go when it is open? We can clearly see the back seats when the cover is open, so does it just curl up in the back roof? It seems like a rather thick cover. I'm guessing it's magic. . .
miscommunication; seemed you were making the broader claim that tonneau covers have a positive effect on aero:
Though, the fact that there’s no definitive data available cuts both ways: if I can’t state the negative effects absent that data, seems you can’t assert the positive effects, either.
No way to look at the vehicle and gauge whether it will be different better, different worse, or different neutral.
My comment was based upon the document. It shows the close path of the vault cover as obstructing with rear window when the vault cover is closed. Either the document in incorrect or I'm missing something which is a possibility ;-)
CT will most definitely be more prone range loss from protruding bed loads than a F150, provided the load on the F150 is below the cab roof height.miscommunication; seemed you were making the broader claim that tonneau covers have a positive effect on aero:
Though, the fact that there’s no definitive data available cuts both ways: if I can’t state the negative effects absent that data, seems you can’t assert the positive effects, either.
But to be clear: I wasn’t asserting negative effects of the CT tonneau design in particular. Since it’s being designed into the truck, I assume they’re designing the aero package for overall affect. That’s what available models show (see below).
No way to look at the vehicle and gauge whether it will be different better, different worse, or different neutral.
Aero can work counterintuitively to the layman eye, or even to expert expectation.
The few professional (but theoretical) aero model studies done on the CT have consistently suggested that they expected the wedge-shaped apex of the truck to cause drag problems, not alleviate them - but despite their expectations we’re surprised to find the shape didn’t cause much drag problem and in fact was efficient, owing to the overall design elements of the CT.
Tesla Cybertruck electric pickup surprises in aerodynamic performance simulation
(Quoting the aero fir“Contrary to what many people would think, the sharp edge of the roof does not produce a big detachment! It is true that the flow it is not attached, but in fact the air follows down the slope quite seamlessly. The boundary layer does not substantially grow. This is quite remarkable and a big aerodynamic advantage compared to other pick-up trucks.”
However, the turbulence that in a typical truck is usually right behind the cab, in the CT “slipped down” the truck to instead behind the tailgate:
“On the other side, our results show clear turbulent structures … The generation of the turbulent structures is caused by the sharpness of these edges. These geometrical features increase the drag of the vehicle, which ultimately reduce the range the CYBERTRUCK. Furthermore, due to the sharp rear end, the flow instantly detaches and creates a considerably big low energy area (wake), mostly noticeable behind the top and side rear-end edges.”
Here’s a second firm, a race car aero firm, that also did a CT model, and had a familiar expectation-to-result experience:
“Across the top of the truck, you have a favorable pressure gradient on the windscreen that leads to the peak in the roofline which trips the flow and causes a region of separation or recirculating flow (read: drag) across the centre section of the truck. This isn’t as big as we’d normally expect as we are running at 100kph which is much lower than our typical race car work. However, despite the small region of separation, the long gentle sloping rear tray cover allows for the flow to reattach and the teardrop shape helps to minimise the wake of the vehicle and reduce drag compared to a typical truck body.”
So yes, the tonneau on the CT does appear a net benefit to aero, owing to the other design features of the truck working in parallel. Which makes since: they’re designing an aero package, not just slapping a slope on the back of the vehicle because to their eye a slope looks aerodynamic.
In contrast, slapping a sloped or normal tonneau on a normal truck, may be a net negative or neutral.
Which raises a potentially interesting issue with the CT as truck: if the expected drag created by the peak is alleviated by the cover, just how negatively will aero be affected by having the tonneau openedv
And maybe more importantly, at times cargo will be sticking up into the airstream that is just over the bed aperture unlike in a normal truck design.
The below comparison of the airflow over a CT vs a Raptor indicates why a tonneau on a normal truck doesn’t do much good:
On a traditional bed design, there’s not much air flowing over the aperature of the bed for a tonneau to effect. (This is also why a paper bag in the back of a truck at speed will twirl around in the area just behind the cab but not fly out - unless a passing truck disturbs the airflow.)
For the same reasons, in a traditional truck design, cargo sticking up above the bed aperture (but lower than the cab height) has little/no aerodynamic effect.
But on the CT, it may be that having the tonneau open means the overall aero goes south - will have to wait and see.
But it certainly means that on a CT cargo sticking above the bed aperture will be directly in airstream and cause turbulence.
That is no small thing: this is the same effect of bicycle racks on the back of Tesla sedans causing 20-30% range reductions.
Then you can start selling snacks out of it at the carnival!Hopefully there is a blowout of some sort because the battery is beneath the bottom of the vault cover.
Or they just open the rear panel storage to access it.
That truck needs a haircut.
