MAX KINGSLEY-JONES / OXFORDSHIRE
The ever-increasing importance of aerodynamics and technology in the design of Formula 1 racing cars has put aerospace engineering skills much in demand
There is nothing like a war or conflict to ensure the accelerated development of new or upgraded equipment for the fighting forces. But most of the time, the aerospace industry's lead times are measured in years rather than weeks or months.
However, there is one sector of aerospace engineering where engineers operate in a war environment 24h a day, every day - Formula 1 (F1) motor racing. The excitement, glamour and financial rewards that the sport offers have made many aeronautically minded people, who set out for a career developing something that is designed to fly, decide to turn their hand to something that flies in two dimensions only - an F1 racing car.
Sir Frank Williams, managing director of the WilliamsF1 racing team, describes the competition within F1 as like a state of war. "I'm often reminded of the situation in the early days of the Second World War when the Spitfire was initially slower than the Messerschmitt 109 and, very quickly, a new, more powerful version was up that could outperform it - there is a similar culture of development in F1," he says. One of WilliamsF1's senior aerodynamicists adds: "You can design a modification and it will be seen on the racetrack in two weeks."
Although the link between the two disciplines may at first seem tenuous, Patrick Head, WilliamsF1 technical director, says there are many parallel or integrated technologies that the two industries are using: A racing car is "nearer a 'ground-plane', but with lots of unaerodynamic structures around, like wheels."
In recent years Flight International has carried a considerable amount of recruitment advertising from F1 teams, including Arrows, Benetton (and its successor RenaultF1), McLaren, and WilliamsF1. With aerodynamics the most obvious common link between aerospace and F1, the teams use the publication principally to recruit aerodynamicists. RenaultF1's technical director Mike Gascoyne, who has a doctorate in fluid mechanics, says that he was pursuing a career in aerospace until he spotted an advertisement by McLaren in the magazine.
In their efforts to minimise weight, F1 teams also use structures technology developed in aerospace and use Flight International to recruit composites design, mechanical design and stress engineers from the industry. With the latest F1 cars incorporating systems as complex as those on current fighter and transport aircraft, aviation engineers and technicians are also in much demand.
The "war" mentality of the F1 teams means that they each operate like a Skunk Works and jealously protect any information about their operation, including their size. WilliamsF1 is believed to have an annual budget of around $200 million and employ around 400 people at its headquarters on the outskirts of the Oxfordshire village of Grove in the UK. Around 50 engineers work in its research and development department. Grove sits in the middle of F1's "silicon valley" - over half of the 11 current F1 teams have their headquarters within a 100km (60 mile)-long stretch of land west of London.
While there is obvious cross-fertilisation between the teams as personnel move around, Head says that WilliamsF1 does not recruit from its rivals on a large scale. "For the general engineering side we've tended to recruit from the aircraft industry," he says. "There are some very, very good young engineers out there. The difficulty is to get engineers with experience," says Head. "We generally take designers with some working experience.
"We have one or two people in the aerodynamics department who we took straight from university, although these have tended to be people we've already been in touch with while they've been at university, or we've assisted them with their PhD and then been very impressed with what they were doing," he says.
Unlike in the aerospace industry, says Head, "engineers working in motor-racing will usually be involved in the development of new structures or systems from start to finish. They will have to oversee the component through the whole process - from design, to manufacture, testing and on to the circuit. The engineer will be expected to work out a plan and project manage."
This whole process is usually measured in weeks or months, rather than years, which is one of the dramatic differences between the cultures of F1 and aerospace. "However, we have found that some people coming to us with sound aerospace backgrounds have better discipline and training that those coming from university or racing backgrounds," says Head.
Aerodynamics has been part of F1 since the late 1960s when aerofoils (or "wings") first appeared on racing cars to produce downforce, but it did not become critical until around 1977-8 when Lotus begun harnessing the power of ground-effect to significantly increase cornering speeds. Although Lotus was the first to adopt successfully the concept in F1, WilliamsF1 is acknowledged as the team that developed ground effect to greatest extent. In those days, F1 teams hired windtunnels for around one week a month (in WilliamsF1's case the tunnel at Imperial College, London). Two days a week the team would be in the tunnel, and the rest of the time at the Grand Prix races.
Now all the top teams have their own bespoke, state-of-the-art, windtunnels, which are in use almost 24h a day. Head says the aerodynamics department is the equivalent in size to that of a whole team 20 years ago. Although details of the WilliamsF1 windtunnel are kept fairly secret, it is believed to able to accommodate a whole car built at 50% scale. Like most teams, WilliamsF1 has a dedicated windtunnel model-making department.
Hand-in-hand with the windtunnel, F1 designers use computational fluid dynamics (CFD) software to understand airflow behaviour over the car. CFD, which is widely used in aerospace and marine engineering, applies the scientific theories of aerodynamics and calculates the motion of fluids or gases when applied to three-dimensional shapes.
WilliamsF1 employs the latest Tru64 Unix-based AlphaServer SC supercomputer supplied by its main sponsor Compaq, which is capable of crunching through a huge amount of data and running complex equations. The CFD code breaks the geometry of a complicated shape into many small parts. The pressure distribution for each part is calculated and the combined value equates to the total aerodynamic forces acting on the whole body.
An F1 car's design is divided among the team of aerodynamicists, with each member given responsibility for a particular area. These areas are broken down into rectangular or triangular flat "panels".
Head says that while CFD can model an complete car, it requires millions of panels and is of questionable accuracy, so generally smaller areas are used for analysis. The full car is modelled at a very coarse level to provide a direction for design, by producing data on the physics of the air- flow, and where certain structures should be positioned.
The models used for CFD are taken from those generated by the computer-aided design (CAD) software used for component manufacture. For the model to work in CFD it has to be simplified slightly and the pre-processing side of the simulation takes all the aerodynamic surfaces and meshes the entire volume around the car - which is a labour- and computer-intensive task.
"An F1 car's wings are comparable to an aircraft on final approach with all its flaps down," says Head. "And all the pieces on an F1 car - wings, sidepods, tyres etc - are massively interactive." This makes the airflow over the car extremely complicated.
Simulating this interaction accurately is a hard task for CFD and, because of this, the windtunnel is the first choice for testing the performance of a new component, says Head. All components are tried in the windtunnel before being produced for a test on the car, but not every change or proposal is necessarily run through CFD.
WilliamsF1 engineers use basic flow visualisation fluid in the windtunnel and some times wool tufts, but rarely use smoke. However, it is still hard to see accurately what the airflow is doing. CFD helps significantly in visualising the flow.
WilliamsF1 says the lead-time to model a new component for CFD is lengthy and parts can usually be prepared more quickly for the windtunnel. If the component shows potential in the tunnel, it would then be fed into the CFD process to understand why it behaved the way it did, before going back to the windtunnel.
Despite having the latest technology available, computer power is still the limiting factor in dictating what the designers can do using CFD. It is expected that as computing power increases, CFD testing of new ideas could be undertaken almost in real time. Very large CFD simulations take several days to run, but it is expected that in a few years those same simulations will only take a few hours.
According to WilliamsF1 aerodynamicists, greater use of CFD is planned for areas where the windtunnels fall short, such as transient aerodynamic testing (eg the effect of the car's vertical motion over bumps), which is difficult to evaluate accurately in the windtunnel.
The constant search for strong, lightweight material is a common pursuit in both aerospace and F1. Teams aim to beat the regulatory minimum weight limit of 600kg (1,300lb, including the driver) for a complete car, to provide flexibility for ballast distribution. "We are always searching for 'unobtainium'," says Head, referring to the ultimate combination of low weight and high strength.
In the early 1980s, composite structures replaced the traditional aluminium honeycomb as the prime material for F1 car construction. Although the earlier aluminium-built cars were already borrowing from the aerospace industry, it was the move to composites that expanded the links. In 1982, WilliamsF1 recruited an ex-Northrop aeronautical engineer, Brian O'Rourke, for his knowledge of composite materials technology and the team often trawls the aerospace sector for similarly skilled people.
"We tend to produce composite components for areas which would not be economic in the aircraft industry," says Head. "Many components are produced as single pieces which aircraft manufacturers would not think of using."
The obvious links to aerospace have seen some F1 teams forging partnerships with players in the industry. McLaren, for example, has close ties with BAE Systems, which is an associate sponsor, and is believed to have access to the company's windtunnel in Warton. WilliamsF1 has had a fairly loose link with Rolls-Royce on materials work, partly through its engine supplier BMW, itself a shareholder in the aero-engine manufacturer.
"You can't get quality standards better than the aircraft industry," says Jeremy Gallimore, an ex-aerospace technician who is now the mechanical inspector at Honda Racing Developments' European headquarters in Bracknell, UK.
As on aircraft, many F1 car components are lifed and detailed records must be logged by serial number of the date of production, number of kilometres accumulated, repairs, etc, says Gallimore. "We apply the same basic quality standards in F1, in that industry safety and reliability are the top priorities. However, the time constraints of F1 can make it hard to apply the same level of checks, and a more flexible approach is needed - there is also less paperwork."
Gallimore spent seven years working as a mechanical/airframe inspector for British Aerospace on airframes, flight controls, systems and assemblies at its Weybridge plant before it closed in 1986.
He then swapped inspecting parts of BAC VC10s and One-Elevens for racing car structures and components. After working for the Tyrrell F1 team in the 1990s, Gallimore is now responsible for quality standards on the Honda three-litre V10 engine that powers the F1 cars produced by British American Racing and Jordan.
"Someone from the aerospace sector is going to be top class - and aviation people will often be hired over an individual with an all-car engineering background," says Gallimore. "If you've been through an aerospace apprenticeship, you will have a better understanding than someone trained purely as a car mechanic."
Wayne Court, a communication systems engineer at McLaren, switched from his role as an avionics specialist at British Airways to pursue a lifelong ambition to work in F1. "I joined McLaren to design and build wiring harnesses, and now I look after the voice and data telemetry systems," he says.
Court's job takes him to every Grand Prix meeting and many test sessions, and he also finds time for a hands-on role during races: "I am responsible for the front wing adjustment during pitstops," he says. Although he works longer hours than at BA, Court says that the rewards, and the remuneration, are much greater.
The competition in F1 is greater than ever. Teams such as WilliamsF1 and McLaren seek every opportunity to create a superior car to the currently dominant Ferrari. "The big aerospace groups have some outstanding talent," says Sir Frank Williams, "and engineers can earn far more in F1". Clearly, the recruitment section of Flight International is going to be busy.
Source: Flight International