Official 2021 Azerbaijan Grand Prix Thread ***SPOILERS***

Official 2021 Azerbaijan Grand Prix Thread ***SPOILERS***

Author
Discussion

kambites

61,488 posts

187 months

allegerita said:
Calculations are difficult without more detailed information
Yeah trying to work it out from the fluid dynamics is well beyond anything I'd attempt (and I have a degree which included a significant amount of it). smile

TheDeuce

9,532 posts

32 months

kiseca said:
TheDeuce said:
Hmm.. The cars would either experience peak g-force or peak aero load, not both at once. One pretty much rules the other out..

I think around 4 tonnes at 200mph is about right. During peak sustained accelerative, decelerative of lateral loads, the car obviously isn't still travelling at 200mph. Not unless something has gone very wrong wink
That doesn't make sense to me? The g-force available is dependant on the aero load. Less aero, less cornering speed available.
G-force is dependant on force acting to oppose the inertia. A car travelling at a constant 200mph with/without aero downforce has 1g, the same as if it were sitting still.

Does downforce define the maximum g a car can generate in a corner? No.. because you also have endless other variables.. A car with slightly less downforce than another could achieve slightly higher lateral g in a corner due to other conditions at the time being more favourable. A car with zero aero downforce still has it's own weight and mechanical grip too of course.


kiseca

9,073 posts

185 months

TheDeuce said:
kiseca said:
TheDeuce said:
Hmm.. The cars would either experience peak g-force or peak aero load, not both at once. One pretty much rules the other out..

I think around 4 tonnes at 200mph is about right. During peak sustained accelerative, decelerative of lateral loads, the car obviously isn't still travelling at 200mph. Not unless something has gone very wrong wink
That doesn't make sense to me? The g-force available is dependant on the aero load. Less aero, less cornering speed available.
G-force is dependant on force acting to oppose the inertia. A car travelling at a constant 200mph with/without aero downforce has 1g, the same as if it were sitting still.

Does downforce define the maximum g a car can generate in a corner? No.. because you also have endless other variables.. A car with slightly less downforce than another could achieve slightly higher lateral g in a corner due to other conditions at the time being more favourable. A car with zero aero downforce still has it's own weight and mechanical grip too of course.
Is downforce one of the variables that defines the maximum g a car can generate in a corner? Yes.

For any given, equal set of variables, is a car with more downforce able to generate more cornering g than an otherwise identical car with less downforce? Yes.

Doesn't matter what the other variables are. You said the car cannot experience both peak g-force and peak aero force both at once. That's what I'm questioning.

G-force ultimately depends on how much grip you can get out of the tyres. The grip depends on the load on the tyres. If you can increase that load, you increase the grip. If you increase that load by making the car heavier, you get more grip but then counter it with more inertia or more momentum, working against the extra grip. If you increase that load with aerodynamic downforce, you don't add more mass to the car. The brakes are still only trying to slow 550kg down even if there's two tons of downforce on the wings.

So, I think you've got it the wrong way around. Peak g-force is available when peak aero force is available. Whatever the other conditions are, for that specific car at any specific moment, if you reduce the aero load at that moment, you reduce the available g-force. If the back wing falls off halfway through a corner while turning at 3G, all of a sudden the car isn't pulling 3G anymore. At least until it hits a barrier.

Same thing with the brakes. Back wings falls off while braking, braking performance will get suddenly worse.

TheDeuce

9,532 posts

32 months

kiseca said:
TheDeuce said:
kiseca said:
TheDeuce said:
Hmm.. The cars would either experience peak g-force or peak aero load, not both at once. One pretty much rules the other out..

I think around 4 tonnes at 200mph is about right. During peak sustained accelerative, decelerative of lateral loads, the car obviously isn't still travelling at 200mph. Not unless something has gone very wrong wink
That doesn't make sense to me? The g-force available is dependant on the aero load. Less aero, less cornering speed available.
G-force is dependant on force acting to oppose the inertia. A car travelling at a constant 200mph with/without aero downforce has 1g, the same as if it were sitting still.

Does downforce define the maximum g a car can generate in a corner? No.. because you also have endless other variables.. A car with slightly less downforce than another could achieve slightly higher lateral g in a corner due to other conditions at the time being more favourable. A car with zero aero downforce still has it's own weight and mechanical grip too of course.
Is downforce one of the variables that defines the maximum g a car can generate in a corner? Yes.

For any given, equal set of variables, is a car with more downforce able to generate more cornering g than an otherwise identical car with less downforce? Yes.

Doesn't matter what the other variables are. You said the car cannot experience both peak g-force and peak aero force both at once. That's what I'm questioning.

G-force ultimately depends on how much grip you can get out of the tyres. The grip depends on the load on the tyres. If you can increase that load, you increase the grip. If you increase that load by making the car heavier, you get more grip but then counter it with more inertia or more momentum, working against the extra grip. If you increase that load with aerodynamic downforce, you don't add more mass to the car. The brakes are still only trying to slow 550kg down even if there's two tons of downforce on the wings.

So, I think you've got it the wrong way around. Peak g-force is available when peak aero force is available. Whatever the other conditions are, for that specific car, if you reduce the aero load at that moment, you reduce the available g-force. If the back wing falls off halfway through a corner while turning at 3G, all of a sudden the car isn't pulling 3G anymore. At least until it hits a barrier.

Same thing with the brakes. Back wings falls off while braking, braking performance will get suddenly worse.
I addressed that part earlier on - yes there is a brief crossover point where the car being at maximum velocity means it has maximum downforce and then, if the brakes are applied heavily but within the level of grip offered by the tyres, yes you fleetingly get both downforce and g-force at very close to their peak levels. I say close as the moment g-force increases, velocity and therefore downforce must decrease in the same instant.

But for the vast majority of time, and F1 car will be experiencing the top end of G force or the top end of it's downforce. They're quite literally designed to favorably exchange one for the other in fact.

It's a shame they don't broadcast the axle loads on TV - I know they never would but it would be fascinating to see the transitions I think.

AlexIT

754 posts

104 months

kambites said:
AlexIT said:
kambites said:
Yes but now we're talking about aero load, which can be estimated pretty accurately from instantaneous peak braking force which is, I'm pretty sure, of the order of 5g. That being the case I can't see how the cars can possibly be generating more than about 3 times their own weight in downforce.
I think, that the problem using this way to judge the actual downforce is that the deceleration is so quick that the aero load decreases dramatically in fractions of a second, so while a 10G braking force at peak downforce might be achievable, by the time the pilot can put enough pressure on the brake pedal the speed has already dropped to a level where downforce is already much lower.
You'd still expect to see 8G+ on the brakes at the end of long straits. Maybe they do and the graphics just don't show it.
Might be, I was thinking out based on your input.

HardtopManual

1,608 posts

132 months

Just re-watching the race, it becomes very obvious that it took absolutely forever to get the safety car out after Max' incident, and quite some time after Stroll's.

The race director then has the temerity to castigate drivers for not slowing down enough under double yellows.

I think the decision on a safety car should be taken out of the RD's hands when a car is stopped on circuit, prompting double waved yellows. There should be an immediate VSC in all cases.

F1 got a pass at the weekend. Max could easily have been in the 45 degree wall at pit entry. Perez, or in fact any of the rest of the field, given that it took 2 mins to call the SC, could easily have suffered a puncture on Max' debris and smashed into his car at 200mph.

kiseca

9,073 posts

185 months

TheDeuce said:
I addressed that part earlier on - yes there is a brief crossover point where the car being at maximum velocity means it has maximum downforce and then, if the brakes are applied heavily but within the level of grip offered by the tyres, yes you fleetingly get both downforce and g-force at very close to their peak levels. I say close as the moment g-force increases, velocity and therefore downforce must decrease in the same instant.

But for the vast majority of time, and F1 car will be experiencing the top end of G force or the top end of it's downforce. They're quite literally designed to favorably exchange one for the other in fact.

It's a shame they don't broadcast the axle loads on TV - I know they never would but it would be fascinating to see the transitions I think.
How do you exchange aero downforce for g-force? That's the bit I'm not following. If you're braking, your downforce reduces as your speed reduces, therefore so does the amount of available grip - counteracted by other variables as you say, but I don't see that as trading one for the other. If somehow you could preserve the aero load while speed reduced - say, with fan driven ground effects, the braking performance throughout most of the braking zone would be even better.

Cornering, even harder for me to see your point because you can corner at a constant speed or even accelerate, so your downforce doesn't change but the g forces will load up as you turn the wheel and lean on the tyres. So again, not exchanging one for the other.

So what am I missing? Where's the exchange?

TheDeuce

9,532 posts

32 months

kiseca said:
TheDeuce said:
I addressed that part earlier on - yes there is a brief crossover point where the car being at maximum velocity means it has maximum downforce and then, if the brakes are applied heavily but within the level of grip offered by the tyres, yes you fleetingly get both downforce and g-force at very close to their peak levels. I say close as the moment g-force increases, velocity and therefore downforce must decrease in the same instant.

But for the vast majority of time, and F1 car will be experiencing the top end of G force or the top end of it's downforce. They're quite literally designed to favorably exchange one for the other in fact.

It's a shame they don't broadcast the axle loads on TV - I know they never would but it would be fascinating to see the transitions I think.
How do you exchange aero downforce for g-force? That's the bit I'm not following. If you're braking, your downforce reduces as your speed reduces, therefore so does the amount of available grip - counteracted by other variables as you say, but I don't see that as trading one for the other. If somehow you could preserve the aero load while speed reduced - say, with fan driven ground effects, the braking performance throughout most of the braking zone would be even better.

Cornering, even harder for me to see your point because you can corner at a constant speed or even accelerate, so your downforce doesn't change but the g forces will load up as you turn the wheel and lean on the tyres. So again, not exchanging one for the other.

So what am I missing? Where's the exchange?
As o keep saying, I'm talking about current F1 cars. The faster they go the higher the downforce, the more braking or cornering the more speed has to be scrubbed and thus the downforce will reduce.

It'll still be significant but we were talking about peak downforce, which obviously isn't at its peak when the car is encountering max g, other than a fleeting crossover.

jsf

22,701 posts

202 months

You are talking nonsense Deuce.

Racecars generate lateral and longitudinal G (and yaw). When travelling at a steady state, say 200mph, they are experiencing Zero G.


kiseca

9,073 posts

185 months

TheDeuce said:
kiseca said:
TheDeuce said:
I addressed that part earlier on - yes there is a brief crossover point where the car being at maximum velocity means it has maximum downforce and then, if the brakes are applied heavily but within the level of grip offered by the tyres, yes you fleetingly get both downforce and g-force at very close to their peak levels. I say close as the moment g-force increases, velocity and therefore downforce must decrease in the same instant.

But for the vast majority of time, and F1 car will be experiencing the top end of G force or the top end of it's downforce. They're quite literally designed to favorably exchange one for the other in fact.

It's a shame they don't broadcast the axle loads on TV - I know they never would but it would be fascinating to see the transitions I think.
How do you exchange aero downforce for g-force? That's the bit I'm not following. If you're braking, your downforce reduces as your speed reduces, therefore so does the amount of available grip - counteracted by other variables as you say, but I don't see that as trading one for the other. If somehow you could preserve the aero load while speed reduced - say, with fan driven ground effects, the braking performance throughout most of the braking zone would be even better.

Cornering, even harder for me to see your point because you can corner at a constant speed or even accelerate, so your downforce doesn't change but the g forces will load up as you turn the wheel and lean on the tyres. So again, not exchanging one for the other.

So what am I missing? Where's the exchange?
As o keep saying, I'm talking about current F1 cars. The faster they go the higher the downforce, the more braking or cornering the more speed has to be scrubbed and thus the downforce will reduce.

It'll still be significant but we were talking about peak downforce, which obviously isn't at its peak when the car is encountering max g, other than a fleeting crossover.
that's not an exchange though. If you had a fast enough corner, you could go through it with the pedal to the metal, at max downforce and max g for as long as the corner lasts and you have power to keep the speed up. You aren't exchanging one for the other.

Yes, I get your point in so much as that you hardly ever see max downforce and max g at the same time, even in my high speed corner example you'd lose some speed to tyre scrub, but that's not exchanging downforce for g. That's just increasing rolling resistance, so in fact the car is at max downforce for that condition, and at max G if the radius is just right and the car is on the limit of grip.

You made it sound like burning fuel to trade it for acceleration. You don't burn downforce and get g-force.

TheDeuce

9,532 posts

32 months

jsf said:
You are talking nonsense Deuce.

Racecars generate lateral and longitudinal G (and yaw). When travelling at a steady state, say 200mph, they are experiencing Zero G.
That's precisely what I said - read back rofl

I said at a constant 200mph they experience 1g. And when parked up, also 1g....

I further went on to point out that anything an F1 car experiences to increase the g force will in some way reduce speed, which will reduce aero downforce to a level below peak.

Edited by TheDeuce on Friday 11th June 16:50

TheDeuce

9,532 posts

32 months

kiseca said:
TheDeuce said:
kiseca said:
TheDeuce said:
I addressed that part earlier on - yes there is a brief crossover point where the car being at maximum velocity means it has maximum downforce and then, if the brakes are applied heavily but within the level of grip offered by the tyres, yes you fleetingly get both downforce and g-force at very close to their peak levels. I say close as the moment g-force increases, velocity and therefore downforce must decrease in the same instant.

But for the vast majority of time, and F1 car will be experiencing the top end of G force or the top end of it's downforce. They're quite literally designed to favorably exchange one for the other in fact.

It's a shame they don't broadcast the axle loads on TV - I know they never would but it would be fascinating to see the transitions I think.
How do you exchange aero downforce for g-force? That's the bit I'm not following. If you're braking, your downforce reduces as your speed reduces, therefore so does the amount of available grip - counteracted by other variables as you say, but I don't see that as trading one for the other. If somehow you could preserve the aero load while speed reduced - say, with fan driven ground effects, the braking performance throughout most of the braking zone would be even better.

Cornering, even harder for me to see your point because you can corner at a constant speed or even accelerate, so your downforce doesn't change but the g forces will load up as you turn the wheel and lean on the tyres. So again, not exchanging one for the other.

So what am I missing? Where's the exchange?
As o keep saying, I'm talking about current F1 cars. The faster they go the higher the downforce, the more braking or cornering the more speed has to be scrubbed and thus the downforce will reduce.

It'll still be significant but we were talking about peak downforce, which obviously isn't at its peak when the car is encountering max g, other than a fleeting crossover.
that's not an exchange though. If you had a fast enough corner, you could go through it with the pedal to the metal, at max downforce and max g for as long as the corner lasts and you have power to keep the speed up. You aren't exchanging one for the other.

Yes, I get your point in so much as that you hardly ever see max downforce and max g at the same time, even in my high speed corner example you'd lose some speed to tyre scrub, but that's not exchanging downforce for g. That's just increasing rolling resistance, so in fact the car is at max downforce for that condition, and at max G if the radius is just right and the car is on the limit of grip.

You made it sound like burning fuel to trade it for acceleration. You don't burn downforce and get g-force.
But it does effectively exchange one for the other - regardless of whether or not it's desirable. As you clearly understand, for all sorts of reasons no car will maintain its max velocity whilst cornering so speed and thus aero downforce will reduce.

Whatever power the car has, it's always faster on the straights, no matter how dedicated you are at pinning the pedal to the metal.


kiseca

9,073 posts

185 months

TheDeuce said:
kiseca said:
TheDeuce said:
kiseca said:
TheDeuce said:
I addressed that part earlier on - yes there is a brief crossover point where the car being at maximum velocity means it has maximum downforce and then, if the brakes are applied heavily but within the level of grip offered by the tyres, yes you fleetingly get both downforce and g-force at very close to their peak levels. I say close as the moment g-force increases, velocity and therefore downforce must decrease in the same instant.

But for the vast majority of time, and F1 car will be experiencing the top end of G force or the top end of it's downforce. They're quite literally designed to favorably exchange one for the other in fact.

It's a shame they don't broadcast the axle loads on TV - I know they never would but it would be fascinating to see the transitions I think.
How do you exchange aero downforce for g-force? That's the bit I'm not following. If you're braking, your downforce reduces as your speed reduces, therefore so does the amount of available grip - counteracted by other variables as you say, but I don't see that as trading one for the other. If somehow you could preserve the aero load while speed reduced - say, with fan driven ground effects, the braking performance throughout most of the braking zone would be even better.

Cornering, even harder for me to see your point because you can corner at a constant speed or even accelerate, so your downforce doesn't change but the g forces will load up as you turn the wheel and lean on the tyres. So again, not exchanging one for the other.

So what am I missing? Where's the exchange?
As o keep saying, I'm talking about current F1 cars. The faster they go the higher the downforce, the more braking or cornering the more speed has to be scrubbed and thus the downforce will reduce.

It'll still be significant but we were talking about peak downforce, which obviously isn't at its peak when the car is encountering max g, other than a fleeting crossover.
that's not an exchange though. If you had a fast enough corner, you could go through it with the pedal to the metal, at max downforce and max g for as long as the corner lasts and you have power to keep the speed up. You aren't exchanging one for the other.

Yes, I get your point in so much as that you hardly ever see max downforce and max g at the same time, even in my high speed corner example you'd lose some speed to tyre scrub, but that's not exchanging downforce for g. That's just increasing rolling resistance, so in fact the car is at max downforce for that condition, and at max G if the radius is just right and the car is on the limit of grip.

You made it sound like burning fuel to trade it for acceleration. You don't burn downforce and get g-force.
But it does effectively exchange one for the other - regardless of whether or not it's desirable. As you clearly understand, for all sorts of reasons no car will maintain its max velocity whilst cornering so speed and thus aero downforce will reduce.

Whatever power the car has, it's always faster on the straights, no matter how dedicated you are at pinning the pedal to the metal.
OK when you put it like that I can see the point of view. I was taking you too literally.

TheDeuce

9,532 posts

32 months

kiseca said:
TheDeuce said:
kiseca said:
TheDeuce said:
kiseca said:
TheDeuce said:
I addressed that part earlier on - yes there is a brief crossover point where the car being at maximum velocity means it has maximum downforce and then, if the brakes are applied heavily but within the level of grip offered by the tyres, yes you fleetingly get both downforce and g-force at very close to their peak levels. I say close as the moment g-force increases, velocity and therefore downforce must decrease in the same instant.

But for the vast majority of time, and F1 car will be experiencing the top end of G force or the top end of it's downforce. They're quite literally designed to favorably exchange one for the other in fact.

It's a shame they don't broadcast the axle loads on TV - I know they never would but it would be fascinating to see the transitions I think.
How do you exchange aero downforce for g-force? That's the bit I'm not following. If you're braking, your downforce reduces as your speed reduces, therefore so does the amount of available grip - counteracted by other variables as you say, but I don't see that as trading one for the other. If somehow you could preserve the aero load while speed reduced - say, with fan driven ground effects, the braking performance throughout most of the braking zone would be even better.

Cornering, even harder for me to see your point because you can corner at a constant speed or even accelerate, so your downforce doesn't change but the g forces will load up as you turn the wheel and lean on the tyres. So again, not exchanging one for the other.

So what am I missing? Where's the exchange?
As o keep saying, I'm talking about current F1 cars. The faster they go the higher the downforce, the more braking or cornering the more speed has to be scrubbed and thus the downforce will reduce.

It'll still be significant but we were talking about peak downforce, which obviously isn't at its peak when the car is encountering max g, other than a fleeting crossover.
that's not an exchange though. If you had a fast enough corner, you could go through it with the pedal to the metal, at max downforce and max g for as long as the corner lasts and you have power to keep the speed up. You aren't exchanging one for the other.

Yes, I get your point in so much as that you hardly ever see max downforce and max g at the same time, even in my high speed corner example you'd lose some speed to tyre scrub, but that's not exchanging downforce for g. That's just increasing rolling resistance, so in fact the car is at max downforce for that condition, and at max G if the radius is just right and the car is on the limit of grip.

You made it sound like burning fuel to trade it for acceleration. You don't burn downforce and get g-force.
But it does effectively exchange one for the other - regardless of whether or not it's desirable. As you clearly understand, for all sorts of reasons no car will maintain its max velocity whilst cornering so speed and thus aero downforce will reduce.

Whatever power the car has, it's always faster on the straights, no matter how dedicated you are at pinning the pedal to the metal.
OK when you put it like that I can see the point of view. I was taking you too literally.
beer

jsf

22,701 posts

202 months

TheDeuce said:
jsf said:
You are talking nonsense Deuce.

Racecars generate lateral and longitudinal G (and yaw). When travelling at a steady state, say 200mph, they are experiencing Zero G.
That's precisely what I said - read back rofl

I said at a constant 200mph they experience 1g. And when parked up, also 1g....

I further went on to point out that anything an F1 car experiences to increase the g force will in some way reduce speed, which will reduce aero downforce to a level below peak.

Edited by TheDeuce on Friday 11th June 16:50
No

At 200mph constant it is Zero G.

Deesee

5,213 posts

49 months


Lateral load/g force is most present at Degner 1 Suzuka..

The cars place so much energy through the surface the Moto GP riders sense check when the arrive, it’s something like 8g lateral in transition.

You can actually see it in the cars.. the compression and load, it’s like they are buckled.

It’s by far and away the most impressive you’ll ever see an f1 car in transition, with traction, under load still somehow going around the track...


Edited by Deesee on Friday 11th June 21:19

kiseca

9,073 posts

185 months

jsf said:
TheDeuce said:
jsf said:
You are talking nonsense Deuce.

Racecars generate lateral and longitudinal G (and yaw). When travelling at a steady state, say 200mph, they are experiencing Zero G.
That's precisely what I said - read back rofl

I said at a constant 200mph they experience 1g. And when parked up, also 1g....

I further went on to point out that anything an F1 car experiences to increase the g force will in some way reduce speed, which will reduce aero downforce to a level below peak.

Edited by TheDeuce on Friday 11th June 16:50
No

At 200mph constant it is Zero G.
I recently read a book from NASA, Elegance In Flight, about an experimental fighter jet: The F-16XL. Every time they referred to straight and level flight, when the aircraft wasn't accelerating in any direction, they called it 1-g flight.

Zero G is weightlessness.

1G is what I'm experiencing right now sitting on my arse typing this. It would also be 1G if I was sitting in a car doing a constant 70mph.

CoolHands

12,846 posts

161 months

I’m travelling about 600mph as I type this. I have my arms tilted so I don’t take off

jsf

22,701 posts

202 months

kiseca said:
I recently read a book from NASA, Elegance In Flight, about an experimental fighter jet: The F-16XL. Every time they referred to straight and level flight, when the aircraft wasn't accelerating in any direction, they called it 1-g flight.

Zero G is weightlessness.

1G is what I'm experiencing right now sitting on my arse typing this. It would also be 1G if I was sitting in a car doing a constant 70mph.
As i said, racecars when discussing G loads are in the lateral and longitudinal direction, the G you experience in aircraft and from gravitational force is in a different plane.

When you are looking at g-g tyre diagrams, its the load path for left right braking acceleration. The path from gravity doesnt come into it. Thats what you are seeing on the onboard graphics.

TheDeuce

9,532 posts

32 months

jsf said:
TheDeuce said:
jsf said:
You are talking nonsense Deuce.

Racecars generate lateral and longitudinal G (and yaw). When travelling at a steady state, say 200mph, they are experiencing Zero G.
That's precisely what I said - read back rofl

I said at a constant 200mph they experience 1g. And when parked up, also 1g....

I further went on to point out that anything an F1 car experiences to increase the g force will in some way reduce speed, which will reduce aero downforce to a level below peak.

Edited by TheDeuce on Friday 11th June 16:50
No

At 200mph constant it is Zero G.
Well right now, unless you're being surprisingly athletic, you're experiencing 1g. God knows what your theoretical F1 car is doing at 200mph to evade earth gravity.


You're talking about lateral g, but failing to make that distinction.

Anyway, on that basis my example still stands. At constant speed or static the g force is the same.

Edit: I see in a later post you have made the distinction wink apologies for speaking too soon and it's lovely to see you flesh out your posts as opposed to simply telling others they're wrong laugh

Edited by TheDeuce on Friday 11th June 22:31


Edited by TheDeuce on Friday 11th June 22:55