Wednesday, January 27, 2010

Dendritic diffusers

The next few days in Formula 1 herald a flurry of new car launches, with Ferrari revealing their 2010 contender on Thursday, McLaren unveiling the MP4-25 at Vodafone's Newbury headquarters on Friday, and Mercedes displaying their silver Schumi-wagen on Monday. The major design novelties are likely to stem from the new requirement to accommodate a race-distance capacity fuel-tank, and a reduction in front tyre widths. Apart from that, there is an expectation in some quarters that many teams will pay Red Bull designer Adrian Newey the ultimate compliment, and effectively copy his RB5 design, the fastest car of last year.

However, whilst almost all the teams may imitate the protrusions on the front nose that Newey used to satisfy the letter of the dimensional regulations in 2009, it is far from certain that the other teams will adopt the pull-rod rear suspension, used to such fine effect on the RB5. The purpose of the pull-rod solution was to remove the suspension rockers, springs and dampers from the top of the car, where they otherwise restrict the flow of air over the top of the diffuser. As Newey himself explained to Alan Henry, the unexpected introduction of double-diffusers severely detracts from the advantages of pull-rod suspension:

"I thought it was an elegant solution to the single-diffuser car, but given the rule changes, it is much more difficult to make the pull-rod layout work satisfactorily in conjunction with a double diffuser.

"We took the decision to use the pull-rods because the start of the diffuser had moved from the front of the rear wheel to the rear axle centre-line. What the double diffuser does is, in effect, to completely circumvent that rule. So certainly the shape of the double diffuser we had latterly on the RB5 was compromised slightly by the pull-rod layout."
(Autocourse 2009-2010, p35)

It may be that to maximise the effect of a double-diffuser, push-rod suspension still offers the best solution. The question is whether one can both maximise the flow through a double-diffuser, and use pull-rod suspension to maximise the flow between the rear wheels, and over the top of the diffuser. When the Red Bull RB6 debuts on February 10th, it will be fascinating to see if Newey's fertile mind has responded to this challenge with an exotic multi-storey diffuser, replete with multiple slots, channels, and branching points. A dendritic diffuser perchance...

Monday, January 25, 2010

The Motorsport Magazine podcast

Podcast chemistry: it's a black art.

Motorsport Magazine's foray into the podcast market has been running now for six months or so, and is somewhat beginning to hit its stride. Introduced by the strangely charismatic Rob Widdows, and featuring Nigel Roebuck, Damien Smith and Ed Foster, it may not have the alchemy of Mayo and Kermode, but it's rapidly developing into an unmissable monthly download.

Highlights so far have included Nigel Roebuck's uncanny impersonation of Niki Lauda, some forthright opinions from Jody Scheckter, and a profanity-laden appearance from John Watson, in which he seemed to suggest that Kimi Raikkonen might prefer to spend the rest of his life getting inebriated.

January's podcast features a remarkable revelation from Nigel Roebuck, in which he recalls being invited, along with then Autosport colleague Mark Hughes, to an audience with Max Mosley. This was three years or so ago, before the succession of scandals which ultimately led to Mosley's downfall.

Presumably looking ahead to the prospect of cars driven by electric power, Mosley posed the following question to Roebuck:

"Will the fans miss the sound of the cars?"

To which Nigel's reply was, um, yes I think they would Max!

Wednesday, January 06, 2010

Ron Dennis and amateur psychology

Former McLaren Racing team principal Ron Dennis has given an interview to Esquire Magazine, ('the magazine for men who mean business'), in which he provides the following insight:

"I used to go to bed with the vacuum cleaner going because my mum wanted the house immaculate when she got up. That’s the ethos I grew up with, everything had to be perfect all the time. That’s why I am such a pain to live with. I don’t want chaos; my homes are my tranquillity bases."

The description of home as a 'tranquillity base', confirms that these are indeed the words of Ron Dennis. However, the vacuum cleaner recollection may be unwise. Many magazine journalists and newspaper feature writers are fond of engaging in the amateur psychological analysis of media personalities, and those who touch on motorsport may now be inclined to suggest that Dennis's perfectionist ethos is the consequence of an inability to satisfy, or the desire to emulate, a dominant and perfectionist mother.

In fact, a perfectionist mother is one of the five 'mothering styles' defined by clinical psychologist Stephan B. Poulter, in his book The Mother Factor: How Your Mother's Emotional Legacy Impacts Your Life:

The Perfectionist Mother — whose family must look perfect in every way
The Unpredictable Mother — whose ups and downs can create lifelong anxiety and depression in her son or daughter
The "Me First" Mother — whose children come second or last
The "Best Friend" Mother — who's now in vogue but can wreak havoc
The Complete Mother — who provides guidance and shows compassion to her child

Dennis is also quoted as stating that his relationship with Ayrton Senna "edged on almost masculine love...I use the word quite deliberately. It didn’t have any homosexuality about it, it wasn’t that sort [of love]." This is touching, but with that final, Alan Partridge-like qualification, again one wonders if Dennis is simply providing his enemies with the ammunition to deride him.

Monday, January 04, 2010

Fortress Madejski

"Oi Shane! Who ate all the pies?"

It's early Saturday evening, and I sit as a Liverpool FC fan, surrounded by Reading FC fans, at the third-round FA Cup encounter between Reading and Liverpool. The heat has long since been vacuumed out of my feet by the concrete floor of the stand below, and the sartorial preferences of the crowd are wisely focused on beanie hats and ugg boots.

The undiscovered comic genius standing a couple of places to the left of me, is artfully drawing attention to the fact that Reading footballer Shane Long has been having some difficulties with his weight this year. Before the evening is out, and this gentlemen presumably wanders off to re-join his friends at the local chess club, he provides another memorable verbal contribution. A Reading defender poleaxes Fernando Torres to the ground just in front of us, and the referee is forced to brandish a yellow card: "Oh fuck off referee!" he shouts. "Is he not supposed to even touch him?"

Watching football in a stadium such as the Madejski can be a strange experience for a motorsport fan, for not only does one sit no more than 20 yards or so from one's heroes, but it's also usually possible to make one's abuse clearly audible to the heroes in question.

Anyway, Reading are playing well, stringing together some nice simple passing moves, and they're exploiting Liverpool's weakness dealing with high balls into the box. As Charlotte, a Reading fan sitting in front of me, points out at half-time: "That's the first time we haven't been booed off this season!"

The pace of the match dwindles slightly in the second half, and it seems there's an altercation occurring in the stand diagonally opposite. It appears that a Liverpool fan has infiltrated the Reading spectators, and is causing a bit of aggro. "Wanker! Wanker! Wanker! Wanker! Wanker!" comes the rhythmic refrain from that part of the ground, as a column of fluorescently-bibbed marshals ascend the stand, and haul the unfortunate scouser from their midst.

Liverpool are as insipid as ever, but then as Emiliano Insua gets the ball at the half-way line, the crowd suddenly rise around me, and begin clapping and cheering. What's this, I wonder? Bizarrely, everyone seems to be looking at a point above pitch level, and I briefly consider the possibility that the messiah has floated into the stadium. Sadly, it's not the messiah, just a very naughty Steve Coppell (Reading's erstwhile managerial hero), who's been spotted in a commentary booth across the other side of the pitch.

As the game draws to a close, I begin to watch Liverpool manager Benitez more closely, as he trundles back and forth to signal his players from the touchline, like a portly clockwork mechanism. I briefly consider shouting some abuse, but realise that "Benitez! You only play attacking football after being criticised in the Spanish press after a Champions' League game!" is probably insufficiently succinct. Instead, I settle for:

"Oi! Benitez! Who ate all the pies?"

Saturday, January 02, 2010

Ayrton Senna and religious experience

In practice for the 1988 Monaco Grand Prix, Ayrton Senna was driven to a previously inaccessible level of performance by his desire not just to beat, but to destroy team-mate Alain Prost. Two seconds a lap quicker than Prost at one stage, Senna subsequently recalled attaining a mental state in which his subconscious mind had gained control, and in which he sensed the opportunity to go even faster, but feeling vulnerable, he decided to step back:

"Suddenly I realised that I was no longer driving the car consciously. I was kind of driving by instinct, only I was in a different dimension. I was way over the limit, but still I was able to find even more. It frightened me because I realised I was well beyond my conscious understanding."

There is a common suggestion that Senna believed he had a religious experience that day. One can hypothesise that as Senna concentrated with laser-like intensity on the rhythm of driving through the unwinding tunnel of barriers at Monte Carlo, he induced himself into a trance-like brain-state, and that what scared him was the feeling of an imminent loss of self-identity, the same feeling commonly induced by many shamanistic religious rituals. In particular, by looking at brain scans conducted on religious devotees engaged in meditation, one can hypothesise that the part of Senna's parietal lobe responsible for the conscious sense of self was shutting down:

Broadly speaking, the left-hemisphere side of this region deals with the individual's sense of their own body image, while its right-hemisphere equivalent handles its context — the space and time inhabited by the self. Maybe, the researchers thought, as the meditators developed the feeling of oneness, they gradually cut these areas off from the usual touch and position signals that help create the body image.

"When you look at people in meditation, they really do turn off their sensations to the outside world. Sights and sounds don't disturb them any more. That may be why the parietal lobe gets no input," says [Andrew] Newberg [a neuroscientist at the University of Pennsylvania in Philadelphia]. Deprived of their usual grist, these regions no longer function normally, and the person feels the boundary between self and other begin to dissolve. And as the spatial and temporal context also disappears, the person feels a sense of infinite space and eternity.

The mystical aura which surrounds Senna's achievements in the sport, and raise them above the achievements of Michael Schumacher in the minds of many, can be attributed in large part to what Senna believed he experienced that day at Monaco, and the vivid manner in which he was able to communicate those experiences. Whilst Senna's beliefs were in a sense delusional, those delusional beliefs may well have been directly responsible for permitting him to access levels of performance denied to other drivers.

Friday, January 01, 2010

Ronnie Peterson and roll resistance

A couple of years ago, ESPN broadcast the full fifty-minute highlights of the 1973 British Grand Prix, complete with commentary by Raymond Baxter. For the motorsport cognoscenti, this was pure manna. Whilst the Grand Prix is infamous for the multi-car accident triggered by Jody Scheckter at the end of the first lap, the re-started race is itself both exciting and interesting.

The dramatis personae consist of the iconic, John Player Special Lotus 72s of Ronnie Peterson and Emerson Fittipaldi, resplendent in their sable and or livery, Jackie Stewart's Tyrrell, and the Yardley McLarens of Denny Hulme and Peter Revson. There is also an impressive cameo from Niki Lauda's BRM, and a strong showing from James Hunt's ridiculously short-wheelbase, Hesketh-run March.

When the race re-starts, the cars on the front row of the grid (Peterson's Lotus, and the McLarens of Hulme and Revson) light up their rear tyres, and the noses of their cars visibly lift! Peterson's Lotus takes an immediate lead, but is hunted down first by Jackie Stewart's Tyrrell, then by Emerson Fittipaldi's similar Lotus, and finally by the McLaren M23 of Peter Revson. Revson eventually slipstreams Peterson down the Hangar straight, calmly takes the lead into Stowe, and ultimately takes the victory.

But what really grabs the attention is the extraordinary body language of the cars. Peterson's high-speed oversteer drift through Woodcote is perhaps one of the most famous images in the history of the sport, but Jackie Stewart looks similarly impressive through the same corner, the right-front wheel of his Tyrrell pawing the inside white line on one particular occasion. (There appear to be no kerbs whatsoever at either the inner or outer margins of the track). In addition, the Lotus 72s both exhibit a quite astonishing amount of chassis roll into corners such as Copse and Stowe, visibly more than all the other cars in the field, which themselves display far greater suspension travel than modern Formula One cars.

Why would this be? Well, according to Paul Fearnley's article on the Lotus 72 in Motorsport magazine (October 2002), Lotus switched from Firestone to Goodyear tyres between the 1972 and 1973 seasons, and with the waning of the erstwhile tyre war, found they were unable to generate sufficient heat in the harder Goodyear tyres. The consequence was that the Lotus 72s suffered from understeer in 1973.

One might therefore hypothesize that Lotus softened the front suspension of the Lotus 72 in an attempt to combat this understeer. To understand why doing so might reduce or eliminate understeer, we need to briefly digress into some vehicle dynamics and suspension theory.

When a car corners, the grip provided by the tyres generates a lateral (centripetal) force towards the inside of the corner. From the perspective of a reference frame in which the car is at rest (a reference frame which effectively travels around the circuit with the car; i.e., the coordinates of the car's centre of gravity remain constant in this reference frame), this induces a reaction force towards the outer wheels of the car. This reaction force is not a real force, but a fictional force, created by the use of a reference frame which is travelling around with an object undergoing acceleratory motion. Such a reference frame is called a non-inertial reference frame. The fictional reaction force is simply the result of the sprung mass of the car attempting to follow an inertial trajectory, in a straight line at a constant speed, when viewed from a reference frame undergoing centripetal acceleration.

The reaction force acts on the centre of gravity, and generates a moment around the roll centres of the front and rear suspension. (In dynamics, a moment is a force which generates a rotation about some axis). This roll moment has the effect of reducing the vertical load on the inner tyres, and increasing the vertical load on the outer tyres. The total load transfer is proportional to the height of the car's centre of gravity, and inversely proportional to the track width (the lateral distance between the wheels).

Generally speaking, this load transfer reduces cornering grip. To maximize cornering grip, one would wish to distribute vertical load equally amongst the inner and outer tyres.

The stiffness of the suspension front and rear, determines the amount of roll which the sprung mass of the car experiences for a given roll moment. The stiffness of the suspension can therefore be referred to as the amount of roll resistance. However, the stiffness of the suspension cannot really alter the total load transfer between the inner and outer pair of wheels. Rather, the relative stiffness of the front and rear suspension can alter the distribution of the total load transfer between the front and rear of the car.

The stiffer the suspension at one end of the car, the greater the load transfer at that end of the car, hence the lower the cornering grip available at that end. Conversely, the softer the suspension at one end, the less the load transfer at that end, and the greater the cornering grip available.

Hence, if a car suffers from understeer, one potential course of action is to soften the front suspension, either by softening the front spring/damper rates, or by means of softening the front anti-roll bar. Such logic might explain why the Lotus 72s wielded by Peterson and Fittipaldi at Silverstone in 1973, exhibited such a remarkable degree of roll.

Racecar suspension expert Mark Ortiz agrees, but also points out that Lotus "could have freed the cars up by stiffening the rear too, which would have reduced the roll, or stiffening the rear a bit and softening the front a bit, keeping the roll about the same.

"In other words, there is no necessary relationship between roll angle and oversteer/understeer balance. Cars that roll more don't always understeer less or oversteer more."

It's the type of speculation rarely open to modern Formula One fans.