Engines III – The Future

(I initially saw the story about the possible new engine rules, decided to write about it, decided to write a bit about the history, a bit about current engines, an article on KERS, and finally now the article about the future regulations. Sorry for the delay.)

Previous entries in this series:

Engines I – The History
Engines – Interim
KERS
Engines II – Contemporary

Although not confirmed, the plans mooted for the new generation of engines from 2013 are 1·5 litre turbo-charged with KERS and direct fuel-injection. The first thing that struck me on reading this is that the monster turbo-engines used in the ‘eighties, that produced around 900 bhp in races and perhaps as much as 1500 bhp in qualification, before being limited then banned, were 1·5 litre turbo-charged! They were replaced by 3·5 litre normally aspirated engines that were less powerful, with engine-size now down to 2·8 to further reduce power and speed.

Clearly, it is not the plan to return to an engine specification that with modern developmental advances would provide about two to three times as much grunt as current engines, plus whatever they could add with KERS. These new engines are supposed to be smaller and more efficient, presumably with a significant drop in power that can be made up with much less restricted KERS. The old turbos crammed extra air (thus extra oxygen) into the cylinders, so more fuel could be added for a bigger bang when combusted, so extra power came with heavier fuel consumption. Presumably, these proposed regulations for 2013 include strict limits on how much boost is allowed from turbo-charging, with the advantage this limit can later be lowered to cut engine-power without wholesale changes in engine rules.

I wonder how low this limit will have to start at. In the last two years of turbo engines in F1, the limit was four bars (four times atmospheric pressure at sea level). This would make 1·5 turbos over 50% more powerful than current engines. They would have to restrict it to two bars or less for a reasonable drop in power, which is mild turbo-charging.

That the engines will feature direct fuel-injection will aid fuel-consumption. This means the fuel is squirted directly into the cylinder whilst the air enters through inlet valves. Currently, the fuel is injected into the air before entering the cylinders. I must admit I am not sure why current F1 engines do not use direct injection – it may be that direct injectors have to be more robust because of the huge pressure changes in cylinders, and this somehow makes it more practical to avoid them. Direct injection is more fuel efficient because it creates a more even fuel-air mix and has a cooling effect in the cylinder that enables higher compression rates without the risk of premature detonation.

(The compression-rate is how much the fuel-air mixture is compressed in the cylinder before ignition. 10:1 means it is squeezed by the compression stroke to a tenth of the volume it started at. Compressing increases the temperature of the fuel-air mix, which if it gets too hot in an already hot cylinder will ignite before compression is complete. This would be very bad because the piston would still be pushing the air-fuel mixture into a smaller space as it exploded, which would involve pieces of metal violently traveling in directions they were not designed for.)

No details are given on the KERS. However, it is interesting that no other energy-recovery systems are mentioned. It is possible that KERS may allow the collection of energy from the front wheels (which provide the majority of the braking retardation) as well as the back, and perhaps with the ability to put some of that power back through the front wheels, since the generators that might collect energy from the front could double as electric motors. Also, will it be push-to-pass, with energy collected used in bursts, or will the stored energy be allowed for use gradually which would make for faster lap-times?

It is a long time until 2013 and these plans will probably change. I was hoping for something a bit more imaginative. I question if it is Formula One’s role to be green but, if that is the agenda, what would be the best way to go about it?

The first thing to examine is the probable future of more efficient road-cars. I will avoid the debate on global warming, but even if it turns out to be bad science (as in the ‘sixties when the story was we were heading towards a new ice-age), it strikes me as a jolly good idea that the World consumption of oil and other fossil-fuels is reduced, and motorists offset rising fuel costs.

Those developing electric cars have often said that in twenty years, they would be as good as petrol cars, forgetting by then that gasoline cars would also be twenty years better. However, in return for lower running costs, if it gets around the city, does 70 mph on the motorway, and has a reasonable range, a lot of people would take that.

The big step is in battery technology. The Tesla, built by Lotus Cars, uses lap-top batteries. A Tesla spokesmen argued that although these batteries are very expensive, if widely used in production cars, through economics of scale, the cost of the batteries would come down to affordable levels. The Tesla uses lithium-ion batteries for which repeated use gradually erodes the amount of charge they can hold. However, new technology reported last year (BBC news story) suggests the future may be lithium-iron-phosphate batteries. These are cheaper, now with the ability to charge many times faster. They are slightly heavier but do not lose their capacity to hold charge, and do not heat up when charged, saving space and weight on the cooling system required for lithium-ion batteries. According to my rough mathematics, this would enable a car with a range of 150 to 200 miles that would recharge in about ten minutes. Looking at the very confusing efficiency data on Wikipedia, I think in cost and resource use, it would be better than 100 mpg.

The first bottleneck on this technology would be that a domestic electricity supply could not provide the sheer amperage for a recharge of less than hours, and even if fast recharging points appeared at fuel stations, for cars to have recharging couplings that could handle that much current without melting might not be practical for some years. The second bottleneck is the time it would take for the price of the lithium-iron-phosphate batteries to become affordable enough.

Listening to an edition of Radio Four’s In Business, I heard of a Chinese start-up that seem to have the most practical solution. It is basically an electric car with a range of fifty to eighty miles with a small conventional engine that charges the batteries if you need to go further. A hybrid, such as the Prius, uses a conventional engine backed by the electric system, which is not that efficient. (The current Prius can not be charged externally so all the charge has to come from the engine or the KERS, and is less efficient than many diesel models.) This Chinese car always runs off the batteries, saves the weight and space of a regular transmission, and even when the batteries are being charged by the engine, runs at higher fuel-efficiency than normal, because the combustion engine can switch on-or-off as needed, always runs at its most efficient speed, and its power is transferred to the wheels more efficiently, essentially with the electronic equivalent of CVT (continuous variable transmission).

So if I was envisaging the car for the near future, it would have enough battery-range for most journeys, the ability to charge up in a few hours at home (also maybe at work), electric motor/generators on all four wheels (so it could use braking to generate electricity), and a small efficient combustion engine to generate electricity beyond the battery range on longer journeys. I would imagine that engine would be a diesel specifically designed to run efficiently at one speed, with a turbine taking power off the exhaust emissions, not to drive a compressor as for a turbocharged engine, but to drive the generator in addition to the engine (a trick the Prius seems to miss). It might have a flywheel (electrical not mechanical) for short-term storage of kinetic energy between stops and starts.

(This brings up the point that mass-manufacturers often ignore what could be learnt from motor-racing anyway. Cosworth, when designing their turbo engine in the 1980s, asked FIA whether if instead of using the exhaust-turbine to power an intake-compressor, they would be allowed to add the power from the turbine directly to the output shaft of the engine (to be told, “No”). Not only in hybrid cars could this exhaust-emission energy be used to generate extra electricity, but there is no reason I can see why normally-aspirated road-cars have not added this recoverable power to their output for the last twenty years. In the ‘nineties, Williams developed CVT strong enough for F1 (to have it banned), but manufacturers ignore this technology that would make engines more efficient.)

Obviously, we do not want diesel-electric cars in Formula One – they just have to be loud petrol engines. My proposal is not to limit engine-size or aspiration-type or energy-recovery options, but to limit fuel usage. Initially, I thought to set a maximum amount of fuel for the race-distance (which would not preclude refuelling) but how to do that for qualification? So instead set a maximum rate for the injection of fuel into the engine (whether direct or not). Leave it entirely up to the designer how to exploit this for maximum effect. The other proviso I would add is a strict limit on replacing batteries so sustainable ones have to be used. It would also be necessary for a qualification lap to limit the use of recovered energy to a small percentage over the energy recovered during that lap, otherwise one-lap speed could get hairy.

It would be fascinating to see what solutions they come up with. Would they use CVT? Would they consider electric generator/motors on the front wheels an advantage, or too much of a packaging issue? How much power could they get off the exhaust emissions, and would they use it to add extra power directly to the rear wheels, to make electricity, turbo-charge the engine, or a combination? How much power would they try to hold in batteries, or would they favour flywheels, and if so, electrical or mechanical? Surely, they would come up with something the car industry could use, and bring back the excitement of true variation in design that F1 has lacked for so long. Just how much less fuel could they use?

 

The biggest technical challenge would be to manage heat-energy recovery which I doubt even the collective ingenuity of F1 folk could manage any time soon. One of the biggest packaging issues for F1 cars is getting rid of heat, mostly via the oil and water radiators in the sidepods, with more heat leaving with the exhaust gasses. If only this energy could be instead be converted into usable energy, the advantage in efficiency would be ground breaking.

Power stations that burn coal, gas, oil or rubbish, and even nuclear plants, use the heat to make steam to drive turbines that generate electricity, in what is essentially updated steam-engine technology. Nuclear-powered submarines use steam-power in which the same water is repeatedly condensed and re-heated to steam. Could something like this ever be made small and light enough for Formula One?

Lear VapordyneAmazingly in 1968, a project was instigated, led by maverick engineer, Ken Wallis (somewhere between genius and scoundrel), and funded by Bill Lear (of Lear jet fame) to build a 4WD steam car to win the Indianapolis 500 (fueled by kerosene). 130 staff were recruited for the project which was also to produce pollution-free road-vehicles. To provide a ‘sanity-check’, the project was based at an ex-air force base in the desert north of Reno, within which Lear announced the intention of building an exact copy of the Indianapolis Motor Speedway track!

The car was heavy and bulky, and never really worked. 4WD was banned for Indy and it became apparent that the equivalency rules when set for steam would not upset the established runners. After two years and many millions of dollars, the Lear Vapordyne project was canned. A senior designer on the project, Bud Fraze, believes that with material and production techniques available today, that it would have worked giving 1000 bhp, tremendous acceleration and high fuel efficiency. Maybe it is not such an unimaginable stretch that modern Formula One could do something with this technology.

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