I well remember reading a story in a museum-piece boys' magazine. Produced in the 1920s, the magazine showed what the editors imagined life would be like in 50 years' time. Their version of the 1970s included a huge airship equipped with all sorts of exciting features. The paradigm shift represented by fixed wing aircraft was yet to occur; although aircraft existed, they were fragile, small things. At the time, passenger-carrying airships were crossing all of the world's major oceans, often on regularly-scheduled services. Why would you have then considered aircraft as being relevant to the future of human transport?
That's one of the traps in trying to make technological predictions - when human endeavour suddenly goes in a direction not even foreseeable, let alone foreseen. The predictions of a telephone engineer one hundred years ago are unlikely to have included the World Wide Web of interconnected electronic machines; although of course other largely telephone-based visual systems like fax machines were then much closer to realisation, and so may have been predicted. And even had that telephone engineer been presented with a précis of the Web as a fait accompli, the implications that the Web has for democracy, the dissemination of knowledge, and world commerce would surely have been furthest from his mind.
But cars are quite different - the paradigm has remained almost constant.
If a turn of the century automotive engineer could be brought back to life and given a current car to examine, he (yes 'he') would be puzzled by many things - the engine management, ABS and airbag, for example - but the majority of parts would hold no surprises. He would find pistons and a crankshaft and a camshaft. Even finding two camshafts in the one engine wouldn't be much of a puzzle - Alfas had DOHC in production cars being made more than eighty years ago.
The seats; the presence of a steering wheel; gauges in front of the driver; four wheels, each with an inflated tyre; drive to the front or rear or all wheels; hydraulically-operated brakes controlled by the driver's foot; suspension using steel springs and dampers - the fundamentals of cars have changed extraordinarily little. However, if that engineer were to drive a current car, he would be stunned - absolute silence, extraordinarily fast and frugal performance - and a whole symphony orchestra at his disposal, should he wish to listen to it. (The societal aspects - cars are ridiculously cheap, their ubiquitousness, the way in which we have constructed our cities so much around these examples of individual transport - these are the things that would surely also stagger him.)
So what has happened to those oft-predicted automotive technologies like battery-electric propulsion, active hydraulic ram suspension, turbine engines, ceramic engines, hover-cars, automatically guided cars - and all of the rest? For a variety of reasons, they haven't occurred. What has happened is a constant refinement of the same old mechanical ingredients, together with a healthy topping of electronics.
To suggest that in the near future this will radically change is to ignore the last 100 years. Unless of course there's one of those paradigm shifts...then all bets are off.
City Cars
The imminent introduction of 42-volt car electrics will mark for some cars a major change in emphasis. I believe that it will be the city cars that will be most altered as a result. When, in normal urban driving, the full power of an engine is so seldom used, it is enormously wasteful to configure the whole car around that maximum power output. If the powertrain of the car can instead be designed around its two disparate requirements - low-power continuous cruise, high-power short-burst acceleration - then the compromises currently evident can be reduced.
And the relationship between the two power sources most likely to be used in hybrid cars - battery (or super-capacitor) power and the traditional internal combustion engine - can be made far more effective when the car electrical system is predicated around a higher, common voltage.
Compared with operating on 13.8 volts (the voltage of a 12V running car), 42-volt electric cars will require only about one-third of the current flow to generate the same power. So a 100 per cent efficient traction engine developing 3kW will need a current of 'only' 71 amps, versus 217 amps if such a system were to be integrated with a conventional 12V car electric system. When accessory power and motive power are operating on the same voltage, the need for doubling-up energy storage in heavy batteries (or trying to efficiently convert DC voltages) is gone.
While breakthroughs in battery technology have been being actively sought for more than a century, no startling developments have really occurred. In the areas of energy density, energy costs of production, mass and safety, the story with batteries remains poor. As a result, hybrid cars will have a relatively small battery capacity - it is still better to carry extra petrol than extra batteries. If a very efficient motor is powered by that petrol, so much the better.
The integration of a 42-volt electric motor (which will also be the starter) with a high-tech internal combustion engine will result in a much more efficient overall package. If the petrol engine (and it will be petrol - forget hydrogen and other fuels; the petrol selling infrastructure is much too large for any widespread changes to occur within decades), is configured for maximum efficiency when driving a generator and/or the wheels, massive decreases in fuel consumption and emissions production will occur.
And how to make that engine efficient? The technologies are already here, but they have not yet been integrated into one engine. Direct fuel injection into the combustion chamber is currently used on diesel engines and just a few petrol engines. Infinitely variable valve timing of both inlet and exhaust cams is carried out on a few engines (eg BMW's M5 V8), and variably tuned intake manifolds exist on many cars. Turbocharging is commonplace. Lean burn, torque-based engine management systems have advantages in both fuel consumption and emissions.
An engine appropriate to a small hybrid city car could easily mix these ingredients: three or four cylinders, variable cam timing, DOHC four-valves-per-cylinder, variable intake manifold, direct fuel injection, and an intercooled turbocharger. A 700 or 800cc engine with these features could develop an incredibly fuel-efficient 80kW, which together with the 2 or 3 electric kilowatts that would be needed to maintain city cruising speeds, would give extremely good performance, economy, and emissions. Torque-based electronic throttle control would improve driveability, reduce emissions and fuel consumption, and allow the seamless transition from electric to petrol power.
Such a car would need to be light and aerodynamically slippery - plastic panels hung on an impact-absorbing aluminium space-frame would mix the right combination of recyclability, major and minor crash safety, and aerodynamic styling ease. Solar cells will be integrated into the upper surfaces, allowing partial recharging of the on-board batteries. Thin section tyres will improve fuel consumption, and the use of electric power steering and electronic stability control will still allow excellent handling on the modest rubber. The low vehicle mass will decrease the required unsprung weight (heavy brakes and beefy suspension members won't be needed), allowing the retention of a good ride. A satellite navigation system will calculate the best route to each destination, based on gradients, road quality, traffic conditions and the calculated journey time.
Think of a cross between a Daewoo Matiz and a Mercedes A-class, using the aluminium space-frame technology of the Audi A2, powered by a turbocharged, upgraded-but-downsized version of the Honda S2000 engine, and matched with Toyota Prius and Honda Insight hybrid technology.
Put that way it all seems fairly straightforward, doesn't it?
Performance Cars
The advent of electronic valve actuation - with the use of sophisticated electric or pneumatic solenoids opening and closing each poppet valve - will utterly change performance engines.
Where the operation of individual cylinder's valves can be set to whatever is best for power, economy and emissions, the internal combustion engine will be revolutionised. Lift, overlap and duration will be able to be altered on an infinitely variable basis for each individual valve. This will result in a silky smooth idle combined with the most radical of performance "grinds" at higher rpm. An individual cylinder will be able to be easily deactivated by the simple expedient of changing its valve timing, and effective (dynamic) compression ratios of each cylinder will also be able to be altered at will.
This variable dynamic compression will allow the use of different fuel octanes, with cylinder-specific knock sensing inputs able to directly alter the peak combustion pressures of individual cylinders. In turbo engines, the cam overlap will be related to the level of boost pressure, allowing the engine to develop torque far more linearly across its rev range. With each valve individually operated, intense combustion chamber swirl will be able to be generated, improving emissions and allowing the use of extremely lean air/fuel ratios. Without the current (relatively low-rpm) occurrence of valve float, redline revs will rise significantly, allowing much greater power development from smaller engine capacities.
Torque-request-based engine management systems with electronic control of cylinder head valve operation, direct in-chamber fuel injection, turbo boost control, and active throttle operation will allow improved power, better emissions and far better fuel economy. The use of an engine torque output sensor will replace the indirect modelling of torque currently used in the latest management systems.
Aerodynamic developments will not only concentrate on achieving low drag coefficients, but also on active stability enhancement. This will take the form of aerodynamic aids that alter in effectiveness, depending on transient conditions. For example, the blowing of air over aerodynamic surfaces will be used to create forces that promote straightline stability, and improve high speed turn-in and braking. Instead of the car being passively stable (for example, affected little by crosswinds), aerodynamic design will concentrate on active stability where aerodynamic centre of pressure movements are made to compensate for instabilities caused by winds and airflow over the car. Flat undertrays will become common.
All control systems currently mechanically connected to the actuators will become electronic - the throttle, brakes and steering. This complete 'drive by wire' approach will allow vastly better compensation for driver error, in that systems such as ABS and Automatic Stability Control can be pre-emptive rather than reactive. It will be difficult to drive a car in a jerky manner, a change resulting in improved economy and decreased emissions. Radar-based cruise control systems, which keep a constant distance from the car in front, will be common.
Intelligent transport system technologies utilising real time communication with GPS navigation will direct drivers to the fastest routes, allowing the avoidance of accidents or roadworks that are delaying traffic. Voice actuation of some car functions will occur; LEDs will replace indicators and rear lights, and high intensity discharge (HID) headlights with motor-driven variable focal length (ie zoom) lenses will be used. The latter will allow the beam spread, depth and intensity of the headlights to be automatically tailored to the ambient light conditions, the distance to other cars, and the speed of the vehicle.
Conclusion
It's easy to make way-out predictions about hydrogen-fuelled gas turbine cars navigating themselves around our streets without human guidance. However, it's much more likely that current state-of-the-art technologies will simply become more widely implemented, with breakthroughs based very much on developments of those current technologies.
And for what timeframe are the above predictions being made? I'd suggest most of these will be in place well within a decade - and perhaps two decades for these technologies to be common.
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