Internal Body Aerodynamics
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rtj
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[ame]https://www.youtube.com/watch?v=7xBMDmaLy5o&t=355s[/ame]
Discusses front end charges to reduce flow underneath.
Pretty pictures:
[ame]https://www.youtube.com/watch?v=LYNliMcHd1U[/ame]
I think the GTM needing a Porsche trans really hurt them. Maybe as c8 wrecks accumulate, they’ll revise the GTM for that power train (GTM-8
).
Discusses front end charges to reduce flow underneath.
Pretty pictures:
[ame]https://www.youtube.com/watch?v=LYNliMcHd1U[/ame]
I think the GTM needing a Porsche trans really hurt them. Maybe as c8 wrecks accumulate, they’ll revise the GTM for that power train (GTM-8
).
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rtj
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All the neat aero developments are $$$.
[ame]https://www.youtube.com/watch?v=XCEkOo5yVK8&app=desktop&persist_app=1[/ame]
Couple of neat things in this one, aerodynamic supercharging and the wind tunnel at Mercedes with the rolling tires.
[ame]https://www.youtube.com/watch?v=KU9XxC7-3NE[/ame]
[ame]https://www.youtube.com/watch?v=XCEkOo5yVK8&app=desktop&persist_app=1[/ame]
Couple of neat things in this one, aerodynamic supercharging and the wind tunnel at Mercedes with the rolling tires.
[ame]https://www.youtube.com/watch?v=KU9XxC7-3NE[/ame]
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mfain
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Canard Aero
Here is something interesting. It looks like the front canards are creating a low pressure area at the top of the fender well causing air to be pulled out. Also note the angle of the airflow out of the fender vents. Looks like providing an airflow exit further back behind the wheel could help reduce pressure in the wheel well which would help downforce.
Here is something interesting. It looks like the front canards are creating a low pressure area at the top of the fender well causing air to be pulled out. Also note the angle of the airflow out of the fender vents. Looks like providing an airflow exit further back behind the wheel could help reduce pressure in the wheel well which would help downforce.
phantomjock
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Pappy -
Nice pic with a lot to digest, so I'll guess...(or bloviate)
I'm thinking that the dual canards are acting as "vanes" and not only creating downforce (vectoring the flow), but also making an "air curtain" to blanket flow just outside the wheel. Yep, that would create a low pressure area. And, I'll bet that the reason we don't see flow further forward on the wheel is because it has all been exhausted over the top of wheel and also out the louvers. That would be a good thing - more low pressure in the wheel well forward of the tire. [Need a magnehelic gauge and some pressure taps to do some analysis.]
I'm disappointed we see no flow out the side exits. They're open - right?
There is some interesting disturbed area between the F/R wheels, and it looks like it may be wrapping around and under. A skirt could fix that - or sharp edge. Curves are nice looking, but judicious use of sharp edges can be useful too.
Just curious - any DAQ onboard? AEM/MOTEC/RT/Harry's Laptimer?
(What do I know - I'm waiting on some bits to complete that damn suspension!)
Cheers - Jim
Nice pic with a lot to digest, so I'll guess...(or bloviate)
I'm thinking that the dual canards are acting as "vanes" and not only creating downforce (vectoring the flow), but also making an "air curtain" to blanket flow just outside the wheel. Yep, that would create a low pressure area. And, I'll bet that the reason we don't see flow further forward on the wheel is because it has all been exhausted over the top of wheel and also out the louvers. That would be a good thing - more low pressure in the wheel well forward of the tire. [Need a magnehelic gauge and some pressure taps to do some analysis.]
I'm disappointed we see no flow out the side exits. They're open - right?
There is some interesting disturbed area between the F/R wheels, and it looks like it may be wrapping around and under. A skirt could fix that - or sharp edge. Curves are nice looking, but judicious use of sharp edges can be useful too.
Just curious - any DAQ onboard? AEM/MOTEC/RT/Harry's Laptimer?
(What do I know - I'm waiting on some bits to complete that damn suspension!)
Cheers - Jim
rtj
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The YouTube guy is pretty critical, might be in over his head on this one.
https://m.youtube.com/watch?pbjreload=101&v=bwVbklHHE4w
https://m.youtube.com/watch?pbjreload=101&v=bwVbklHHE4w
rtj
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The manufacturer video.
At 10:30 he sits in the car and fires it up, the smile on his face says it all
https://m.youtube.com/watch?pbjreload=101&v=ShJ0i8xIUzI
At 10:30 he sits in the car and fires it up, the smile on his face says it all
https://m.youtube.com/watch?pbjreload=101&v=ShJ0i8xIUzI
phantomjock
Well-known member
Hmmm... I'm pretty much "in-gee" with 99% of his observations. I too am puzzled at their choice of nomenclature for Cd. Also, a bit disappointed Kyle didn't use a bit of CAD to get a more accurate frontal area. Although no good shots of the new car I guess.
His notes on the diffuser are spot on I'd say - and I bet they went with the easy build (straight vanes) after all the other complex work. Sad though.
Cheers - Jim
FWIW - He is putting together an on-line Aero course, but won't be cheap I bet.
rtj
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My guess is they (Bugatti) have done cfd and wind tunnel testing. He doesn’t know what is going on before the exit of the diffuser, with all that internal flow through the doors etc, it may have been used in the diffuser to control bl. So, the exit shapes would not be conventional.
He’s also very critical of the dimples. Again, Bugatti isn’t divulging much, my guess is they put some work in there. Kyle wants to add material instead of the dimples, but that will impact the wing.
He’s also critical of the front splitter, but they move a lot of air internally so that might result in a non conventional design.
Notice the factory doesn’t go into a lot of aero detail other than their coefficient info, no cfd plots of any kind.
I like Kyle’s vids, he just seem too negative on this one.
I would like to be able to afford one, but that won’t happen anytime soon
He’s also very critical of the dimples. Again, Bugatti isn’t divulging much, my guess is they put some work in there. Kyle wants to add material instead of the dimples, but that will impact the wing.
He’s also critical of the front splitter, but they move a lot of air internally so that might result in a non conventional design.
Notice the factory doesn’t go into a lot of aero detail other than their coefficient info, no cfd plots of any kind.
I like Kyle’s vids, he just seem too negative on this one.
I would like to be able to afford one, but that won’t happen anytime soon
rtj
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rtj
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My new favorite YouTuber!
Just kidding, but her enthusiasm is contagious.
https://m.youtube.com/watch?pbjreload=101&v=_SB7h2kB6Eg
Just kidding, but her enthusiasm is contagious.
https://m.youtube.com/watch?pbjreload=101&v=_SB7h2kB6Eg
phantomjock
Well-known member
My bet - the Scoop.
WHY?
The camber of the scoop is pretty radical, as compared to what Kyle was suggesting as a smoother transition in the previous video. The flow is highly likely to separate anyway, and have a region of high skin friction before the separation region.
The Dimples, surface roughness (like maybe a vinyl top recall the "drama" Mark D. + Penske NASCAR?), a trip wire, or even VGs could be used to "turbulate*" the boundary layer as well. That would reduce skin friction and by re-energizing the near-field flow help fill the region behind the scoop. Yes, I'd really like to see some CFD here. And, I bet they are using the dimples to tailor the separation zone.
Yes/No? Just one guy's opinion.
But - on the other hand - it is a cool idea (the others could work too), and the dimples on the scoop make for real cool marketing ploy and heaps of armchair aero-discussions.
I'll admit - I haven't caught the video - just yet, so these observations may be subject to "recall." OK - Watched it. He is glossing over the 10% --I'll still stick with the scoop.
Cheers - Jim
OK -- I did a bit of figuring;
So what is 10%? Is it the whole car Cd?
The Chiron drag data is available and I'll use it for similitude (a cool term- eh?).
In low drag the Chiron Cd is 0.38.in drive around mode, in handling mode up to 0.40, and then drops to 0.35 in top speed mode.
Handling mode is going to have some induce drag from wing downforce increases, and the dimples only function in High Speed Mode, so I'll only use Top Speed Mode Cd.
If the Chiron had Dimples which came into function at the high speed range, And, if the Dimples reduced the whole car Cd - that would be 0.315.
WOW! That would be SIGNIFICANT.
Now to the Bolide:
Using Kyle's estimate of the Bolide low drag configuration of 0.3522. With DIMPLES it would be 0.317 (whole car) using Kyle's Cd estimate. Since the Bolide is only moderately faster than the Chiron (again, it has no dimples), I suggest the 10 percent reduction in drag on the Bolide is just the scoop. Else, there would be a much larger difference in the top speeds.
Lastly, I'll also suggest his Cd is pretty close to what we might expect on the Bolide. We must wait for further details.
I love saying this, "Class Dismissed..."
* Please not the Urban Dictionary Definition!
Cheers - Jim
WHY?
The camber of the scoop is pretty radical, as compared to what Kyle was suggesting as a smoother transition in the previous video. The flow is highly likely to separate anyway, and have a region of high skin friction before the separation region.
The Dimples, surface roughness (like maybe a vinyl top recall the "drama" Mark D. + Penske NASCAR?), a trip wire, or even VGs could be used to "turbulate*" the boundary layer as well. That would reduce skin friction and by re-energizing the near-field flow help fill the region behind the scoop. Yes, I'd really like to see some CFD here. And, I bet they are using the dimples to tailor the separation zone.
Yes/No? Just one guy's opinion.
But - on the other hand - it is a cool idea (the others could work too), and the dimples on the scoop make for real cool marketing ploy and heaps of armchair aero-discussions.
I'll admit - I haven't caught the video - just yet, so these observations may be subject to "recall." OK - Watched it. He is glossing over the 10% --I'll still stick with the scoop.
Cheers - Jim
OK -- I did a bit of figuring;
So what is 10%? Is it the whole car Cd?
The Chiron drag data is available and I'll use it for similitude (a cool term- eh?).
In low drag the Chiron Cd is 0.38.in drive around mode, in handling mode up to 0.40, and then drops to 0.35 in top speed mode.
Handling mode is going to have some induce drag from wing downforce increases, and the dimples only function in High Speed Mode, so I'll only use Top Speed Mode Cd.
If the Chiron had Dimples which came into function at the high speed range, And, if the Dimples reduced the whole car Cd - that would be 0.315.
WOW! That would be SIGNIFICANT.
Now to the Bolide:
Using Kyle's estimate of the Bolide low drag configuration of 0.3522. With DIMPLES it would be 0.317 (whole car) using Kyle's Cd estimate. Since the Bolide is only moderately faster than the Chiron (again, it has no dimples), I suggest the 10 percent reduction in drag on the Bolide is just the scoop. Else, there would be a much larger difference in the top speeds.
Lastly, I'll also suggest his Cd is pretty close to what we might expect on the Bolide. We must wait for further details.
I love saying this, "Class Dismissed..."
* Please not the Urban Dictionary Definition!
Cheers - Jim
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rtj
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10 % of the total seems like a lot, but if the scoop had an issue in one region (or regions) and messed up the rear wing aero, I guess that would make sense.
The dimples seem like a lot of work, so they must have their reasons.
With those wheel fans, that thing is sort of like a vacuum cleaner ( for lack of a better description).
At $10M each, they will be able to afford lots of R&D.
The dimples seem like a lot of work, so they must have their reasons.
With those wheel fans, that thing is sort of like a vacuum cleaner ( for lack of a better description).
At $10M each, they will be able to afford lots of R&D.
