whole new raft of challenges for Formula 1 engine manufacturers. The engine rule book has literally been re-written and engineers have a brand new challenge to get their teeth into. The shift is profound, as
A
Andy Cowell, engineering director of Mercedes AMG High Performance Engines in Brixworth, UK explains: ‘The spirit of the regulations is going from where the power is controlled by revs and capacity to where it is controlled by a fuel flow,’ he said. This may not be a new idea – Keith Duckworth of Cosworth proposed it for F1 more than three decades ago – but, whatever the arguments for it in the past, the global mood of the moment regarding energy supply
fter years of tinkering around the edges within the current engine freeze rules, 2014 brings a
and the environment has made it a particularly relevant solution. The rules were thrashed out with the engine manufacturers and Cowell, as someone party to both drafting and exploiting them, is a good person to comment. Despite the first season under the new rules being two years away, Mercedes has already constructed the first version of its engine, which is due to run on the dyno soon. It may seem early but the importance of iterative engine development is fully appreciated at Brixworth.
BY THE NUMBERS The power unit’s architecture is largely dictated by the rules, so the Mercedes engine is a turbocharged, 90-degree V6. An 80mm bore is mandated by the rules so, as Cowell points out, the company has no need to explore other alternatives, meaning one
“five [power units] per driver per season, dropping to four for 2015”
“the importance of iterative engine development is fully appreciated”
less variable to consider. Coupled with a maximum
capacity of 1.6-litres, the bore size dictates a maximum stroke of 53mm, or a bore-to-stroke ratio of 1.5:1. However, with the current normally-aspirated engines, ratios of 2.5:1 are allowed and Cowell hinted that it may be better to go for a more advantageous ratio, even at the expense of capacity. But, then again, as there is currently no turbo boost limit in the rules, a capacity deficit might not be the handicap it at first appears. Usually, the appeal of extreme
bore-to-stroke ratios is to keep piston speeds down when pushing revs higher, but the 2014 engines will be limited to 15,000rpm, ultimately dictating the potential for gains in this area. Recalling the last turbo era during the 1980s, when engines were delivering between 1000- 1500bhp in qualifying trim, the scope for runaway power
development seems unlimited, but this is where the fuel flow formula steps in. From 2014, F1 cars will be constrained to a maximum fuel flow of 100kg/h and a maximum fuel load of 100kg. That is about 35 per cent less than today. Obviously, if this fuel flow was used continuously from the start, the car would not make it to the end of the race, so the rules also only allow this flow rate above 10,500rpm. Below this, it is dictated by a formula down to 5kg/h to zero rpm. This is to prevent manufacturers coming up with low revving engines that develop very high torque. ‘It is about internal combustion engine efficiency and energy management using the ERS (Energy Recovery Systems) for best lap time,’ says Cowell.
ELECTRIC AVENUE The mass flow rate also provides a challenge for the fuel manufacturer. As Chan Ming Yau
KERS was first used in 2009, and made a return in 2011, but Energy Recovery Systems (ERS) will play a major part in Formula 1 from 2014 onwards February 2012 •
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