Downforce throughout the years?

[jjn9128]

For Tyrrell F1 cars (SAE paper from Ben Agathangelou and Mike Gascoyne), frontal area = 1,47m2, all values are for ballance conditions of 36% on the front

Those years were not particularly successful for Tyrrell, so the top teams could be a fair percentage better. Any clue which cars the Peter Wright are? I assume 2000 is the Ferrari as he wrote a book about it. As ever with these things there's a chunk of salt to be taken with whatever is presented publicly.

[Nonserviam85]

Does anyone know the CL and L/D values for 2019 cars? Just being curious...

[jjn9128]

Does anyone know the CL and L/D values for 2019 cars? Just being curious...

L/D has been around 5 for a few seasons and Cd is around 0.7-0.8 so Cl is around 3.5-4. Exact value depends on circuit and car. So it's only a ballpark.

[timbo]

1992: 2750lbs@150mph
1993: 2450lbs@150mph

Why such a change between 1992 and 1993? I thought the aero regulations were pretty much the same, no?

In 1993 aero rules have been changed, smaller rear wing (950mm above ground) and mainly overall width from 2150mm to 2000mm , front wing overhang from 1000 to 900mm.
And yeas it varies from team to team. So it could be different for top runners like williams.

Thanks, I only remembered that rear tyre width changed. Now indeed pre-1993 F1 cars seem quite wide in the pictures.

[Fulcrum]

Some unfounded assumptions from an admitted armchair expert(i.e. not informed opinion). Please expand, refute, deny, modify etc...

• The more complex the surface, the less likely the resultant vehicle wake will be laminar?

• Modern wings (2010's) have a higher density of trailing vortices than wings from the 70's/80's/90's/00's?

• Air interacting with a moving component (i.e. wheels) is more difficult and expensive to model (i.e. computationally simulate) than interaction with a "static" surface?

• The majority, or a very significant amount, of turbulent flow in modern F1 cars is generated by the tyres?

As per the above, I have no real idea, just asking.

I'd like to know in how many ways and to what extent I am wrong.

[Tommy Cookers]

.... Please expand, refute, deny, modify etc...

• The more complex the surface, the less likely the resultant vehicle wake will be laminar?

• Modern wings (2010's) have a higher density of trailing vortices than wings from the 70's/80's/90's/00's?

....

well since you ask and imo - in the absence of our usual expert responders ...

you don't seem to distinguish between attached flow (apparently smooth) and detached flow (apparently not smooth)

smooth but turbulent flow (attached) is mostly the best we (aircraft or LSR) can get
(btw if a wake was laminar would we even call it a wake ?)
remember in essence the vehicle is moving and the air is still
tip vortices aren't trailing (if trailing implies attachment) - they are detached and persistent ie tend to infinite length
the main span wake is trailing ie attached and non-persistent and about 1 chord in length

[Potto]

So did the ground-effect cars have a lot lower top speeds than the previous cars? They didn't generally have more power than 1976-1977 cars but with a lot more downforce they shouldn't be nearly as fast on the straights, right?

The reason I'm asking is because I've been playing a lot of simracing and drove both ground-effect and earlier 1970's cars. Of course video-games don't represent real-life perfectly, but it was interesting to note just how slow the ground-effect car was on the straights with zero top-end power but still fast acceleration to match earlier cars below 200 Km/H or so.

[jjn9128]

So did the ground-effect cars have a lot lower top speeds than the previous cars? They didn't generally have more power than 1976-1977 cars but with a lot more downforce they shouldn't be nearly as fast on the straights, right?

The reason I'm asking is because I've been playing a lot of simracing and drove both ground-effect and earlier 1970's cars. Of course video-games don't represent real-life perfectly, but it was interesting to note just how slow the ground-effect car was on the straights with zero top-end power but still fast acceleration to match earlier cars below 200 Km/H or so.

It would make sense that the top speed is lower. Downforce isn't free, even from ground-effect, it's something which is often misrepresented. Creating downforce, no matter how, is putting 'energy' into the air which would otherwise allow the car pass through with less resistance. The benefits for corner speed as well as traction/acceleration and braking are just too great for lap-time though.

I think the misunderstanding in part comes from studies on lifting wings, which shed drag with smaller ground clearances because the reduced circulation weakens the tip vortex - so reducing induced drag. On the other hand inverted wings get a near exponential increase in drag with reducing ground clearance, partly because the tip vortex gets stronger because of the Venturi effect massively reducing pressure under the wing, thereby increasing the pressure differential at the tip.

Depending on the sim the models are actually pretty good. A lot of the F1 simulators started with commercial racesims, though they've evolved into much more detailed, bespoke, models.

[jjn9128]

So did the ground-effect cars have a lot lower top speeds than the previous cars? They didn't generally have more power than 1976-1977 cars but with a lot more downforce they shouldn't be nearly as fast on the straights, right?

The reason I'm asking is because I've been playing a lot of simracing and drove both ground-effect and earlier 1970's cars. Of course video-games don't represent real-life perfectly, but it was interesting to note just how slow the ground-effect car was on the straights with zero top-end power but still fast acceleration to match earlier cars below 200 Km/H or so.

It would make sense that the top speed is lower. Downforce isn't free, even from ground-effect, it's something which is often misrepresented. Creating downforce, no matter how, is putting 'energy' into the air which would otherwise allow the car pass through with less resistance. The benefits for corner speed as well as traction/acceleration and braking are just too great for lap-time though.

I think the misunderstanding in part comes from studies on lifting wings, which shed drag with smaller ground clearances because the reduced circulation weakens the tip vortex - so reducing induced drag. On the other hand inverted wings get a near exponential increase in drag with reducing ground clearance, partly because the tip vortex gets stronger because of the Venturi effect massively reducing pressure under the wing, thereby increasing the pressure differential at the tip.

Depending on the sim the models are actually pretty good. A lot of the F1 simulators started with commercial racesims, though they've evolved into much more detailed, bespoke, models.