Aero and overtaking In F1
Discussion
Interesting comment from Martin Brundle about the problems overtaking and the fact it seesm to come from the unsettling effect of the dirty air from the rear of the leading car over the front wing of the car behind. His answer is to allow better under body aerodynamics and remove as many "wings" or part of as possible. Any body have any experience of this.
Been common knowledge for decades.
The problems began in 1983 when underfloor generated downforce was effectively banned in F1. This placed more reliance on "wings" and other top mounted aerodynamic devices.
The solution is to ban wings and allow SOME underfloor downforce.
But they'll never do that - for two reasons:
i) - wings provide extra space for sponsor logos therefore maximising team income. Pathetic I know but often quoted by team owners.
ii) - if wings are banned in F1, they would probably need to be banned in all the lower feeder formulae (F Renault, F3, GP2 etc etc)as it would be very unfair for a driver having graduated up through winged formulae suddenly to have to cope with a low downforce 900 bhp monster. Interesting maybe, but probably very dangerous.
The problems began in 1983 when underfloor generated downforce was effectively banned in F1. This placed more reliance on "wings" and other top mounted aerodynamic devices.
The solution is to ban wings and allow SOME underfloor downforce.
But they'll never do that - for two reasons:
i) - wings provide extra space for sponsor logos therefore maximising team income. Pathetic I know but often quoted by team owners.
ii) - if wings are banned in F1, they would probably need to be banned in all the lower feeder formulae (F Renault, F3, GP2 etc etc)as it would be very unfair for a driver having graduated up through winged formulae suddenly to have to cope with a low downforce 900 bhp monster. Interesting maybe, but probably very dangerous.
I'm also not convinced that it would make all that much difference. I'm pretty sure that the dirty air following an F1 car is not simply down to it generating downforce, but that the aerodynamic surfaces are designed specifically to disrupt the air as much as possible behind the car so long as it doesn't affect the lift/drag of the car. As a result, if all aero was done under-body, they'd still find some way of disrupting this air and it would possibly be even more difficult for the following car to clean up the airflow before it enters the tunnels.
LexSport said:
I'm also not convinced that it would make all that much difference. I'm pretty sure that the dirty air following an F1 car is not simply down to it generating downforce, but that the aerodynamic surfaces are designed specifically to disrupt the air as much as possible behind the car so long as it doesn't affect the lift/drag of the car. As a result, if all aero was done under-body, they'd still find some way of disrupting this air and it would possibly be even more difficult for the following car to clean up the airflow before it enters the tunnels.
Without wings the following car would not care how "dirty" the air flow is. Unless your going to find a way to force air under the following car. And i'm not sure you can do that!
Funnily enough, I can't find much in the way of F1 results and statistics for the 1683 Season!
F1 cars are not designed to deliberately disrupt the airflow over the cars running behind. This is just a natural result of the way airflow behaves after it has been "used" by the vehicle to generate downforce. In fact, before downforce became the holy grail of motor racing (1968/69 onwards), the disrupted airflow was actually "beneficial" to following cars. You only have to look at video footage of the Italian GP at Monza in 1967, 69 and 71 to see haow cars could run closely together in low or no downforce configurations.
F1 cars are not designed to deliberately disrupt the airflow over the cars running behind. This is just a natural result of the way airflow behaves after it has been "used" by the vehicle to generate downforce. In fact, before downforce became the holy grail of motor racing (1968/69 onwards), the disrupted airflow was actually "beneficial" to following cars. You only have to look at video footage of the Italian GP at Monza in 1967, 69 and 71 to see haow cars could run closely together in low or no downforce configurations.
Munter said:I beg to differ. Any aero devices require attached, laminar flow. Any disruption to the airflow caused by following another car will reduce the effectiveness of these devices. Underbody, ground effect aero basically makes use of the body as an aerofoil combined with the added ground effect that amplifies the effect. That's certainly my understanding from reading up on the subject, but that of course doesn't preclude me from being wildly wrong. It has been known.
Without wings the following car would not care how "dirty" the air flow is. Unless your going to find a way to force air under the following car. And i'm not sure you can do that!
I think a massive overhaul of the technical regulations is the only thing that will make any difference at all to the overtaking problem.
IMHO a major problem is that all the cars are 'cookie cutter' designs at the moment, with relatively little innovation and distinction allowed under the rules. My suggestion would therefore be to allow the designers more freedom to innovate and design around the problem so that the drivers can race closely. Also, if there were lots of distinct cars with different engines, it would mix things up alot.
Gordon Murray was IIRC asked to re-draw the rules a while ago, but his suggestions were never taken up. I would adopt his suggestion, that a wire mesh frame be constructed to define rough shape and dimensions, and that so long as the car fitted within it, it would be legal. I would suggest complementing that with the engine rules being free, the only restriction being that the race must be completed using a specified maximum amount of fuel.
If you think back to the early 90's, the racing was much better then (apart from Williams who routinely finished a minute ahead of everything else), but the cars were very different then - wider full slicks, widebody cars, active suspension, lower front wings with fancy endplates - all things thrown away and with them has gone the close racing.
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IMHO a major problem is that all the cars are 'cookie cutter' designs at the moment, with relatively little innovation and distinction allowed under the rules. My suggestion would therefore be to allow the designers more freedom to innovate and design around the problem so that the drivers can race closely. Also, if there were lots of distinct cars with different engines, it would mix things up alot.
Gordon Murray was IIRC asked to re-draw the rules a while ago, but his suggestions were never taken up. I would adopt his suggestion, that a wire mesh frame be constructed to define rough shape and dimensions, and that so long as the car fitted within it, it would be legal. I would suggest complementing that with the engine rules being free, the only restriction being that the race must be completed using a specified maximum amount of fuel.
If you think back to the early 90's, the racing was much better then (apart from Williams who routinely finished a minute ahead of everything else), but the cars were very different then - wider full slicks, widebody cars, active suspension, lower front wings with fancy endplates - all things thrown away and with them has gone the close racing.
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The key to whether dirty air has an impact on the following car's downforce levels depends very much on how the car is generating that downforce. With the ban on underfloor generated downforce, modern F1 cars are heavily dependent on aerofoils, particularly the front wings. Front wings gained even more importance in the mid 1990s when the FIA ordered that rear aerofoils be lowered dramatically to well below the top of the airbox.
Front wings are extremely vulnerable to disrupted air purely because they are the first part of the following car to meet this turbulence. A car with underfloor tunnels or venturi has the opportunity to tidy up the airflow before it starts creating a suction effect under the car. As was mentioned earlier, in some races in 1981 and 1982, a number of cars ran without any front wings at all as they were getting superior quality downforce from the venturi and could dispense with the front aerofoils completely.
Front wings are extremely vulnerable to disrupted air purely because they are the first part of the following car to meet this turbulence. A car with underfloor tunnels or venturi has the opportunity to tidy up the airflow before it starts creating a suction effect under the car. As was mentioned earlier, in some races in 1981 and 1982, a number of cars ran without any front wings at all as they were getting superior quality downforce from the venturi and could dispense with the front aerofoils completely.
My understanding is that Brundle is completely wrong. The 20005 regs may well have made the cars more susceptible to wake turbulence, but as I understand it the underfloor (which still delivers the bulk of the downforce) is very sensitive to acheiving perfect flow. In attempting to maximise underfloor downforce, the designers have had to go even closer to a knife-edge - when running in disturbed air, it is the underfloor that suffers most.
The high front wing should work as a classic aerofoil (rather than creating a venturi effect underneath), and should be less susceptible to turbulence. Other series (particularly IRL and ChampCar/OWRS) run deliberately (regulated) inefficient underbody aerodynamics and large wings (on road courses) and have little difficulty running close together. This hardly supports Brundle's theory.
Teams have considered how their wae can upset following cars. The most obvious example was apparently Williams a couple of years back. The trailing edge of the rear wing featured a sawtooth pattern. This apparently created a line of small vortices rather than two large oes. I heard that this did nothing for the car's performance, but was intended to disrupt following cars.
Having said that, I'm not an aero-expert, so would be interested if anyone has better knowledge.
The high front wing should work as a classic aerofoil (rather than creating a venturi effect underneath), and should be less susceptible to turbulence. Other series (particularly IRL and ChampCar/OWRS) run deliberately (regulated) inefficient underbody aerodynamics and large wings (on road courses) and have little difficulty running close together. This hardly supports Brundle's theory.
Teams have considered how their wae can upset following cars. The most obvious example was apparently Williams a couple of years back. The trailing edge of the rear wing featured a sawtooth pattern. This apparently created a line of small vortices rather than two large oes. I heard that this did nothing for the car's performance, but was intended to disrupt following cars.
Having said that, I'm not an aero-expert, so would be interested if anyone has better knowledge.
HiRich said:My reading was the opposite - the small vorticies create less drag than the big ones, hence performance increase.
The most obvious example was apparently Williams a couple of years back. The trailing edge of the rear wing featured a sawtooth pattern. This apparently created a line of small vortices rather than two large oes.
However - I too am more than acustom to being wrong on such issues.
Rich
You can see sawtooth patterns on many parts of the cars, not just the rear wings. McLaren have run crennelated gurneys on their front wings, and Ferrari have/had sawtooth edges on the bottom part of their barge boards, which run parallel to the track surface. However, I seem to recall reading somwehere that their origin was in Indy Lights circa 1997, but they first appeared in F1 on the McLaren in 2001.
The general principle IIRC is that they provide the same increase in downforce to a traditional gurney, but with roughly a 30% reduction in drag. To put it technically, they generate vorticity to control flow distortions, thereby reducing instability in the wake (Karman vortex street) - ie breaking up large vortices by using lots of mini-vortices, leaving a fairly smooth flow.
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The general principle IIRC is that they provide the same increase in downforce to a traditional gurney, but with roughly a 30% reduction in drag. To put it technically, they generate vorticity to control flow distortions, thereby reducing instability in the wake (Karman vortex street) - ie breaking up large vortices by using lots of mini-vortices, leaving a fairly smooth flow.
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