- 1,833
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- WarriusZero
It's a mini batmobile? 
GTDesigned: A Community Vision GT Project
- Thread starter LosCules24SFA
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- 4,193
- UK
Kind of, except much lighter and rotary powered.It's a mini batmobile?
- 2,308
- United States
- monkeylima
Even though they didn't invent or were the first to put it in a car
R5
(Banned)
- 7,527
- Location, Location
But they do own the rights to it if I remember correctly.
- 3,440
- Keasbey, NJ
- Smurfybug
- Smurfybug
Kei just annoys the 🤬 out of me, I hate that name lmao, but Ignore me as I'm am a Ps3 peasantWho said anything about 'Mazda'?... Maybe i should have said 'Dynakinectic powered' or something. The engine would still be of the rotary kind. Besides, iv'e changed the name to 'Kei Class Roto Fighter' or just 'Roto Fighter' for short'.
- 2,308
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- monkeylima
- 3,440
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- Smurfybug
- Smurfybug
Awsm thing is I ain't getting a Ps4 for a while
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- 4,193
- UK
Here's the kind of engine i was thinking. (It reminds me a bit of an engine that @YukinoSuzuka designed/modeled)
GoTek Dynakinetic (rotary) engine:
Imagine a bank of these:
Slight update of the 'Kei Class Roto Fighter'
Added some shutlines and rear lights:
GoTek Dynakinetic (rotary) engine:
Imagine a bank of these:
Slight update of the 'Kei Class Roto Fighter'
Added some shutlines and rear lights:
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- 7,527
- Exorcet
- OE Exorcet
While it looks good I think it has a lift problem. Nothing on the upper surface is pushing it down and there is a lot pulling it off the ground. The really sharp transition from the front fascia to wheelwell will produce a lot of separation and a large drag area.
The angular wheelwell design could be a problem too, though they also might produce a slight amount of downforce. It wouldn't be anything to celebrate about though. The rear fascia has no separation edge anywhere which could lead to massive drag
- 57
- United States
I tried to make Nessy's Kei Class Roto Fighter a little more aero.
-Added vents on the front end, to reduce lift.
-Broadened the front fascia in front of the front tires, included a "reverse mudflap" to block the tire a bit more.
-Reduced the size and scale of the side vents. I think having a flat side for the air to reattach to after the front tires is good.
-Added a rear skirt over the rear wheels to compliment the change above.
-Added a rear wing for downforce and clean separation.
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- 3,440
- Keasbey, NJ
- Smurfybug
- Smurfybug
.... Not bad
- 1,833
- United Kingdom
- WarriusZero
Please don't cover any wheels!
- 7,527
- Exorcet
- OE Exorcet
The low pressure under the car depends on a number of things. Peak negative pressure could very easily be over the driver's cabin though, so even with low pressure under the car it could still produce net lift. Then of course there are the wheels which tend to produce lift themselves.
A wing and canards can be more than enough to fix the lift issues, they just need to be sized correctly, but depending on how the car is supposed to look, they may be considered out of place. They will also noticeably reduce top speed and fuel economy. Integrating aero into the shape of the car would be more efficient.
Biggest things would be:
round the front end so air can make it smoothly around the sides, you could also try to direct more air under the car for more downforce or use a splitter
Tame the rear end into something with a more clearly defined separation edge, also avoid as much as possible rear end curvature. If you wanted to keep curves, try using a duckbill type spoiler shape.
This car I think is shaped a bit better for aero. What I would be most concerned about is how the large openings at the front are handled. Right now it looks like they use convex curvature, which looks like it would be draggy. The headlight fairings also point straight forward, but the airflow is going to be pushed to the sides.
It's hard to completely predict what the flow will do there without a really well defined model and some CFD though.
- 4,193
- UK
@Exorcet
Thanks for shedding more light on the subject. And thanks @grannyshifter for adding to the design. With regards to the old design, here's a really quick sketch to show some of the hidden curves under the bodywork, (not the chassis though). Would the front not work very well? (aero dynamically speaking).
(Drawing isn't exact and i know i haven't really translated it well on the original sketch i shared, but this is kind of how i'd thought it'd go) :
Also, would the movable vanes have any affect if they moved when turning (differently on each side, respective of what direction the cars turning). I can appreciate we need actual aero software, but it would be nice to know if we're in the right ballpark. 👍
[EDIT]
Another sketch i was working on earlier today, of the rear of the Roto-Fighter.
Thanks for shedding more light on the subject. And thanks @grannyshifter for adding to the design. With regards to the old design, here's a really quick sketch to show some of the hidden curves under the bodywork, (not the chassis though). Would the front not work very well? (aero dynamically speaking).
(Drawing isn't exact and i know i haven't really translated it well on the original sketch i shared, but this is kind of how i'd thought it'd go) :
Also, would the movable vanes have any affect if they moved when turning (differently on each side, respective of what direction the cars turning). I can appreciate we need actual aero software, but it would be nice to know if we're in the right ballpark. 👍[EDIT]
Another sketch i was working on earlier today, of the rear of the Roto-Fighter.
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R5
(Banned)
- 7,527
- Location, Location
On the subject of our own designs...
I had an idea for a retro-modern supercar idea, it's roughly Vauxhall Astra sized (obviously not as tall) and uses a compact V6 turbo engine related to the F1 power units of today. The engine is then mated to a Formula E Motor in the place of an ERS unit in constant Qualifying spec.
Styling is a typical 80s wedge with modern flourishes such as the vents in front of the rear wheels, and the flying buttresses which hide the air brakes. The front lights are lasers which are arranged in the thin strip, while the rears are LEDs arranged in a similar style to those of a Ferrari 512 Testarossa.
I had an idea for a retro-modern supercar idea, it's roughly Vauxhall Astra sized (obviously not as tall) and uses a compact V6 turbo engine related to the F1 power units of today. The engine is then mated to a Formula E Motor in the place of an ERS unit in constant Qualifying spec.
Styling is a typical 80s wedge with modern flourishes such as the vents in front of the rear wheels, and the flying buttresses which hide the air brakes. The front lights are lasers which are arranged in the thin strip, while the rears are LEDs arranged in a similar style to those of a Ferrari 512 Testarossa.
- 1,390
- <--- This place
- CHALLENGER1ON1
Added some shutlines and rear lights:
It's a radical design. I like it, the fron especially. Although, I believe that the OP stated the car is MR, so maybe the cockpit should be more upfront?
Also, the side vents are huuuuge. Compared to the rest of the car, it seems somewhat out of place.
But so far, great work 👍
- 7,527
- Exorcet
- OE Exorcet
@Exorcet
Thanks for shedding more light on the subject. And thanks @grannyshifter for adding to the design. With regards to the old design, here's a really quick sketch to show some of the hidden curves under the bodywork, (not the chassis though). Would the front not work very well? (aero dynamically speaking).
(Drawing isn't exact and i know i haven't really translated it well on the original sketch i shared, but this is kind of how i'd thought it'd go) :
There might be a bit too much space there between the front and rear wheels, the flow is likely to separate off the front wheel pods. For a design like that it would actually be beneficial if the body bulged out by the vanes. You could also put the front and rear wheels in one continuous fairing (more like a LMP) and reduce the size of the side vents.
Moveable vanes could be useful in yaw or maybe for providing a little bit of downforce on the inside wheels during a turn, but would be better handled by traditional aero surfaces. For functionality, the vanes could open and close if they were intended for cooling.
That's a common misconception. Driving air into a closed space increases pressure, but the underside of a car isn't closed. You're forcing air that is very hesitant to change density (which is the case at Mach numbers below ~.3) to go through a smaller area not a volume. Because of mass conservation, it must speed up, and the Bernoulli equation tells us that if it speeds up pressure goes down.
In picture form, the more compressed the underside streamlines are after going under the car, the more downforce the underside will make. You see a blue low pressure peak under the leading edge of the splitter here and lower than ambient pressure under the rest of the car.
Also notice the suction peak on top of the car, which is why things like a passenger cabin are bad news for lift. Cars by their nature don't want to stick to the road.
- 607
- Low Head, Tasmania
- Kembro45
I agree that to create a ground effect the air speed needs to increase, but from my understanding this is more about reducing the cross sectional area that the air is passing through like lowering the car to increase the air speed, not increase the amount of air being forced under it. Here's an explanation I found.
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- Exorcet
- OE Exorcet
It's all equivalent, getting more air under the car means you're making the cross sectional area ratio more drastic which means the acceleration will be greater.
For a car you can assume that air density (rho) is constant.
You can measure the amount of air that passes through a given cross sectional area by: rho*V*A (density * Velocity * Area)
Mass cannot be created or destroyed so whatever air passes through that area is conserved.
Now we have this equation: M = rho*V*A where M is massflow and is a fixed number. You can double check with unit math
mass/time = (mass/length*length*length)(length/time)(length*length) =
(mass*length*length*length)/(length*length*length*time) = mass/time
So rho*V*A must always be the same no matter how the numbers change. If A is cut in half, rho and V must change to keep M the same. However rho never changes. Only V can change.
V = M/(rho*A)
Make every number 1 and we have 1 = 1/1*1
Change the last 1 which is A to .5 and you get 2 = 1/1*.5
The velocity doubled when the area was halved.
Going back to the picture I posed before you can actually measure the area ratio by taking the height of the streamline that goes just under the splitter before and after the splitter. If the initial height is made higher, the area ratio becomes more extreme and the pressure under the car is reduced. The initial height will also increase M for a given rho and V, so you can see that passing more air under the car leads to more downforce.
