In all sectors of manufacturing, it’s absolutely vital to reduce the design to production cycle. Time is literally money. In no sector is this pressure greatest than in automotive manufacturing.
Anecdotal stories are legion of the major car manufacturer who experienced a six-month delay in launching a key vehicle that cost the company billions of dollars.
Yet with Formula 1, this pressure is ratcheted up even more. Teams at the track are constantly receiving real time information relating to the performance of the car at any given instance. This analysis data is used by teams to make design changes. Deadlines are the most stringent as teams struggle to implement these changes, especially in aerodynamics, that can add racewinning performance enhancements to their cars.
Traditionally ,the way in which to test these aerodynamics changes has been to test models of the design of whole cars (and parts, 50% scale) using wind tunnels. Whilst providing excellent feedback for race engineers and wind tunnels are expensive and inflexible. Over the last decade advances in computer aided design technology have progressed to the point where some wind tunnel activity can be simulated using specialist computational techniques.
Being able to use computer simulations to replace some, if not all, of the wind tunnel requirement will give engineers flexibility and will give their managers welcome injection of funds to reinvest in the manufacturing company. Yet this will only come about with computer technology that is flexible, scalable and cost effective and that does not compromise on delivering the required results as can be obtained by using the wind tunnel method.
Toyota Formula 1 is one such team that is taking the computational route as it strives to gain that competitive edge in the most competitive of arenas. A relative newcomer to the Formula 1 arena, Toyota has a long and proud history in the world of motor sport, dating back to the 1960’s.
In the 1970s, Toyota began to make its mark in the world of rallying with legendary Finnish driver Hannu Mikkola winning his country’s famous 1,000 Lakes Rally in 1975. Further success came in Toyota’s domestic racing scene and in the mid 1980s, the team made its debut in the Le Mans 24 Hours, achieving a second place in both 1992 and 1999. As the 1990s closed, Toyota began to make a name for itself in the ChampCars arena and it seemed only natural that the team would progress to Formula 1 racing. Indeed in 2001 the team launched and got on the Formula 1 gird in 2002.
Early races were successful when, continuing the history of Finnish drivers behind the wheel, Mika Salo scored championship points on the team’s debut at Melbourne and subsequently at the Brazilian grand prix. This first year was essentially an introductory one and racing aficionados were impressed at the efforts of a brand new team that made both the car’s chassis and its engine.
Last year’s formula 1 team, with drivers Olivier Panis and Cristiano da Matta, showed a lot of improvement upon the previous year, with the Toyota car making a strong finish to the season with at one memorable point da Matta leading the British Grand prix for 17 laps. The team has currently accrued 27 Grand Prix points and many are tipping Toyota for even better things with the team having hired the highly regarded Mike Gascoyne as technical director.
Over 600 people work at the Toyota F1 Cologne base where the engineers are engaged in a battle to stay at the top of the grid and IT is very much part of their armoury.
This is in the form of evaluating the aerodynamic behaviour of the car using a technology called computational fluid dynamics (CFD), combined with development in the wind tunnel. CFD essentially breaks down the area of interest to engineers - that is the interface between air and the car body-into a series of thousands of interconnected small meshes with thousands of elements.
The software then calculates the way in which air flows in the basis of the meshes just as it would in the real world. The smaller the mesh size, the more detailed and accurate the analysis of the air flow at that point. With such calculations the designers can make modifications to the car bodies to improve performance relative to the data that they obtained from the track.
Toyota’s hardware comprises a server cluster based on 160 workstations each equipped with two Itanium 2 processors, 4Gbytes of Ram and specially equipped interconnections technology to ensure very high data throughput. With CFD, Toyota’s engineers can gain many advantages that make all the difference yet only by working to tight deadlines.
Explains Waldemar Klemm: “During the race season we have really only two weeks to do some changes. This is a little bit depending on the next track we are going to, it is something between let’s say 10 and 15% [that] you are going to change on parts.
“This is really a lot of things. In comparison to commercial cars, within two weeks you will never ever change that much, you do not have the chance. Therefore, this fluid dynamics principle we are using is really essential. Because imagine, if you do not have such a tool in place you always need to have, to build up a model, after the design, and to go to a wind tunnel.
“The wind tunnel is only limited to 24 hours a day, so that means you can’t do that much on different variants which are really [what we] need. We fight for a real improvement or not. This is, if you like, a substitution of one, two, or three wind tunnels.”
As well as cutting out the time taken to test designs until they are correct the use of CFD has other advantages. Says Toshiro Kurusu: “The advantage of CFD [is that] we can see the air flow. In the wind tunnel it is very difficult to know how the air is going. So for the CFD study we can have an overview [of how] the air is going under, what air is coming through and things like that.
“So our engineer has a clear overview of air. And the other area we are making a parameter study. If we were to approach the design team there [would be] some concept and some different designs. We will make a CFD calculation using three or four types of wing. And to select the most efficient wing we would produce a 50% scale model to confirm how effective [the design is] in the wind tunnel.”
With its computer technology, Toyota can test either the full car or parts of it, and, says, Waldemar Klemm, with great results: If we are
going to calculate let’s say a complete part, up to a complete car, this is always a little bit difficult, as you may imagine. So before we haven’t had the capability and the calculation power to do that.
“So, usually if you have that much calculation power, whether you could use the whole entity for one calculation or you could do a partition of your environment and do, let’s say, several variants of the calculation. So what we are doing is that we are doing
several calculations per day of different variants. For some of these calculations we have a speed up of a factor by 10 times faster than before.”
Each computer is effectively its own wind tunnel which in the real world could cost many millions of pounds and take up to two years to build and get running. Yet the computer technology will never replace totally wind tunnels. Waldemar Klemm explains: “We need to have at least one wind tunnel. No one could really decide whether [CFD] results have any correlation to the real world. So to gain this correlation means you need to get nearly the same results by a one tunnel test.
“And at the same time, you need to get the same or nearly the same results at a real test. And if you have this correlation between this, let’s say technicalcalculations, the safety calculation, the wind tunnel result and the real test at the track, then you exactly know that there is a real connection to the real world. That means that, let’s say, your calculation really makes sense.”
Toyota says that it has been “astonished” as to how quickly, by the use of computer technology in design and testing, it has saved so much money and how much it has cut down on the number of parts it has had to produce.
Such results are the fruits of nearly a year’s work in finding the correct hardware and software to do the job. Says Klemm: “As you may imagine there is a combination of the appropriate calculation power-which is certainly or definitely given with the Itanium 2-and you
have to choose very carefully for your applications and for your environment for structure. Let’s say the mixture of all this is the key to success.”
Even though they have been successful, Toyota’s engineers are ever hungrier for more technical power. The current CFD programme calculates air flow in a steady state and soon Toyota will investigate non-steady state flows and for this it will need more calculation power. Klemm believes that the cluster will be expanded as the engineers look at more detailed analyses including CFD calculations within the engine area of the cars. The latter will take place by the beginning of next year.
Success in Formula 1 is very much a team effort and the guys in the design and testing department will be of vital importance. The Toyota Formula 1 team is on an upward track in terms of improvement in races and no small part of this improvement can be traced to the engineering department.
As we should expect the design team to produce even better work, thanks in no small part to the technology at its disposal, the results of such work should be seen on the track.
This was first published in November 2004