Why things change and why they stay the same

One thing that often worries me is people’s constant misunderstanding of “technology”. Many seem to think that “technology” can solve all our energy and climate related problems, be it new reactor designs, fusion power, geo-engineering or unconventional fossil fuel extraction. The way some people would talk you’d be forgiven for thinking that technology is some sort of ethereal force, like some form of plugin phone app that can be downloaded and installed to fix any situation. Got a problem? Install technology!

Certainly it is true that technology has transformed the world as we know it. But many forget that technology is driven by the laws of physics. And those same laws can often limit what technology can achieve.

In this series of articles I will demonstrate how technology has radically changed things, often in subtle ways we don’t notice. But equally as I will highlight why there are sound scientific reasons why certain technological changes will take along period of time to implement, while others concepts will always remain pipe dreams.

Part I – The Car

I saw a video the other day, from an old episode of Fifth Gear (from 2008 I believe), in which they simulate a crash test between a late 90’s Volvo 940 estate (that would be the “tank” in the picture below!) and a 2005 Renault Modus (a European “supermini” sized car). Now which of these two cars do you think would be the safest to be driving in? Think about it for a minute before viewing the video or reading on further.

Figure 1, A 2008 renault Modus v’s the 1990’s beast from the north [Credit:Channel Five UK]

Yes, looks can be deceiving! The little Modus held up pretty well to the crash. Now as an engineer I wasn’t entirely surprised with this outcome, I had a sneaking suspicion that the Volvo would always come off second best (even though Volvo’s have a pretty good safety record and Renault’s haven’t), but even I was surprised at how clear cut it was (i.e. the Volvo driver would have been pretty much cut out of the car and crippled for life, while the Modus driver would have been walking wounded).

Figure 2, Action shot of Modus v’s Volvo, crash, note the deep penetration into the Volvo’s bonnet [Credit:Channel Five UK]

Indeed in this video from the US, a 2009 Chevy is crashed into a 1959 Bel Air. The result is even more dramatic. The 2009 drivers hobbles away with an injured foot, while the Bel-Air driver would probably have been killed outright.

At the other extreme, here’s a video from 2007 of a Chinese made medium sedan (large car by European standards) BS6 “Brillance” being crash tested (and the result is not so “brilliant” !). As you can see it pretty much crumples up like a violin (it essentially fails the test). So bigger (and newer) isn’t necessarily better, particularly when it comes from a country with only a recent tradition of building cars.

Of course all three of these examples blows out of the water the myth that you need to be driving a big car to be save on the roads. I think its also important as it illustrates how much the car has changed in the course of fifty years.

The technology of car safety

So, how could a poky little French car stand up to a Norwegian battering ram? Well because we’ve seen a revolution in recent years in car vehicle safety. Features such airbags (no just the simple steering wheel ones any more), side impact bars, anti-lock breaks, seat belt pre-tensioners, driver assist features (stability control, collision avoidance, parking assist) and most importantly improved vehicle design (more on this later), have made cars much safer. Even though worldwide the numbers of cars on the road is growing and average speeds are rising, the ages and experience of drivers is falling, in short every statistic that should be producing an increased death rate is increasing, instead the rate of vehicle related deaths, in most developed countries, is falling.

Figure 3, Road Traffic injuries and fatalities for Scotland [Credit: Statistics Scotland], similar trends can be observed in most developed countries, although fatalities are rising in developing countries

While it may not be apparent to the untrained eye, the car’s of today bears little resemblance to those of the past, other than the fact they run on petroleum, have 4 wheels and are (mostly) made of stainless steel (more on that later).

If you took a modern 2012 car back in time to the 60’s and let a mechanic lift the bonnet, for him it would be like lifting the bonnet on an alien spacecraft. There are more electronics and sensors in a modern car than on the lunar lander. Throw in a Sat-Nav and you have better navigation tools available that 1960’s pilot’s used to get across the Atlantic. And it should be noted that those computers aren’t just keeping the car safe or defeating car thieves (these days, cars are becoming near impossible to steal without access to the key), but they are also being used to manage the engine and other systems to optimise performance and flag up any fault.

Indeed the effects of our computer revolution are more integral to the car than merely its electronics. Most modern car’s will have been designed on computer (CAD or sometimes referred too as Computer Aided Engineering or CAE for short). And I don’t just mean some draughtsman drew the car and its parts out on a PC, no it would have actually designed using computer software.

A large part of the reason why the Modus weathered that Volvo storm would have been down to a technology call Finite Element Analysis (FEA, one of the topics I teach in!). This allows one to simulate on a computer, the stresses and deformation rates in a component under load. Consequently, with enough time and computing power, its possible to even run full scale crash tests on the computer and work out how a car (or individual part of a car) will perform, before any steel is cut. Better yet, FEA technology allows for the optimisation of a design, by modifying a component to make it as light as possible, but still make sure its either strong enough, or deforms the way you want it too (counter intuitively you actually want certain parts of a car to deform in a crash as this provides a degree of sacrificial protection to other parts of the car, such as where the passengers are sitting!).

Figure 4, Crash Test simulation using LS-DYNA® [Credit: Engineer’s Eye]

In addition FEA’s little brother CFD (Computational Fluid Dynamics) has had a enormous effect on vehicle aerodynamics. Modern cars are sleeker than those of the past, yet still stick to the road (due to downforce, unlike an airplane sometimes a car that’s too sleek isn’t a good idea!), and are thus both faster and more fuel efficient, not to mention safer too (a number of the cars of other era’s has odd and sometimes dangerous quirks at speed often caused by poor aerodynamics).

Figure 5, Example of Automotive CFD computed streamlines using Star-CCM® [Credit: Modified.com]

And we don’t just use computers to design and run the car, but also to build them. Computer Aided Manufacturing technology means how cars are made these days (even though automation in car factories isn’t anything new) has moved on quite a lot in the last few decades. One downside of FEA, is it can sometimes lead to quite integrate shapes being churned out. While in the past mass producing such parts could have been difficult, now that isn’t a problem. Technology such as CNC laser cutting of sheet metal parts, Rapid Prototyping and Hydroforming means the tools in the manufacturing engineer’s toolbox are quite considerable.

But some things never change – The car and climate change

Of course before we finish congratulating ourselves, the very things about the modern car that we’d most like to change are the very things that will be hardest to achieve – notably that petroleum powered, climate changing, reciprocating IC engine. Road transport is one of the largest net contributors to climate change and when it comes to issues such as peak oil shortages, it is the transport industry (rather than power generation) where the bulk of the effects will be felt.

Figure 6, On the left a Honda Civic Engine (2010) and on the right a Ford engine of the 1970’s

Modern car engines, again thanks to computer aided design, improvements in materials science, DOHC, VTEC and fuel injection (nice article on all of these technologies in How-stuff-works) are a very different and altogether cleaner beast than engines of the past. Anyone whose been keeping watch on vehicle emissions data will have likely noticed how the pollution levels of certain classes of cars (at least those sold within the EU anyway!) has been gradually falling year on year.

Figure 7, Thanks to improvements in technology the emissions of cars continues to fall [Credit: Treehugger.com based on SMMT data]

Unfortunately the fact that many of us have been “scaling up” our cars (buying bigger ones), that there are more of them on the roads and that modern cars come with (as noted) lots more electronic gizmo’s and power hungry air-con systems, all means that much of these gains have been largely cancelled out and unfortunately vehicle related greenhouse gas emissions are still on the rise, even in the West. So clearly, if we’re ever going to get serious about climate change mitigation, never mind how we’re going to run the world’s car fleet post peak oil, that petrol engine has to go….but what’s going to replace it?

Electric cars? I would note that we should really call it the revival of the electric car, rather than the development of them, as quite a number of the early cars were powered by electric engines. It was only when IC engine technology caught up and the desire for a longer range and higher speeds took hold, that the car became the petrol powered beasties we know today.

Now while I’m no fan of Jeremy Clarkson (see my views on him here , interestingly my spell checker keeps trying to change his name to “Clackers”) and I know he and top gear almost certainly faked a few of those “breakdowns” of electric cars on his show, but I am in reluctant agreement with him on one point – the electric car cannot currently (and probably never will be able too) supply a like for like replacement with the IC engine.

Don’t get me wrong, there are a wide number of motoring roles that can be fill with electric vehicles. They are an excellent power source for commuter vehicles, and short to medium range goods vehicles and buses (the majority of car journeys within the EU are 25 miles or less). I suspect that maybe as much as 50% of all motor vehicles could be swapped over to run on electricity. However, I suspect the other 50% will prove difficult if not impossible to convert. This is largely because of the economics, limited battery life, range (nice wikipedia summary of these issues) as well as the long time it takes to charge cars up to full juice. A long distance lorry driver, nor a traveling salesman, nor a London to Glasgow bus, nor a police constable or doctor in a rural district, can afford to waste 6-12 hours at a crucial moment waiting for the battery to recharge.

Indeed personally, as someone who only uses a car for occasional leisure activities (i.e. the occasional long range car journey, I prefer public transport or cycling & walking instead, indeed my car has sat idle for two weeks now!) only a handful of the car journey’s I’ve taken recently would have been within the range of an electric car (and a few of them were in a taxi!).

And let’s not even get started on the thorny issue of how we charge all those car batteries. While the “concept” of using renewables to charge electric cars and then using those batteries to even out the peaks and troughs in the grid is a well established principle. There is a world of a difference between “theory” and “practice” and it largely depends on what sort of future electricity grid we are imagining. This paper here discusses one or two of the pro’s and con’s.

Figure 8, Average and maximum impact on the daily electric power request profile [Credit: Perujo & Ciuffo 2010]

As I’ve previously discussed on Greenblog, this issue might not be so much a technical problem, but a social problem. That is to say that it might be a case of just ditching this concept of the individually owned automobile in favour of some system of collective ownership. The only reason why I might drive my car to France in summer (not that I ever have) is due to the difficulty in acquiring a car at short notice when I get there.

So if electric cars alone aren’t up to the task what about biofuels? Again I would note, this is more a matter of resurrecting an overlooked idea than a new one, as Rudolf Diesel originally designed his engine to run primarily on biofuels (what we now call “Diesel” was substituted later). Unfortunately there is the issue as to whether biofuels are taking away valuable farmland that can be otherwise used for food production. Methanol fuel produced directly from carbon dioxide and water is being production tested on an industrial scale in Iceland (using geothermal heat as the primary energy source) could potentially get around these problems.

Again, don’t get me wrong, biofuels can help, notably in aviation and with long range heavy goods vehicles. But they are no silver bullet.

Hydrogen cars? I would firstly correct the notion that hydrogen cars can ONLY be powered by a fuel cell. Not true, you can convert an IC engine to run on hydrogen also. Which is just as well, as I often hear not very nice things said about fuel cell powered cars from the very people who are doing the research. The is a still a bit of a question mark over them as regards range and reliability.

The key advantages of the fuel cell is that it is quiet, compact and has a very high thermal efficiency. Although I would note that Stirling/Hybrid engine concept (a Stirling engine in a car isn’t necessarily as daft as it sounds, read here) also boasts high efficiency and are probably more practical to mass produce (as things currently stand). Also gas turbine engines (again not as daft as it sounds, read here) also boast compactness and high efficiency (not as high as the fuel cell mind, but better than an IC engine). Both the GT and Stirling engine are fully compatible with both biofuels and hydrogen.

Whether the hydrogen car takes off and what “power pack” gets used really depends on the timescales we’re talking. The longer it takes to build all that hydrogen infrastructure, the more time to prefect the fuel cells. The closer to the present, the more likely it will be some form of IC type engine, or possibly a GT or Stirling hybrid.

But ultimately the key obstacle is still, where does all that hydrogen comes from? And how long will it take to fit hydrogen pumps to everyone of the UK’s 8,700 odd filling stations? And how do we ship the hydrogen around the country? I discuss issues relating to this future hydrogen economy here and here. But suffice to say that, as with the electric car, its a case of where does the energy ultimately come from and how long will it take to build all the support infrastructure?

New Urbanism

Inevitably, I would therefore argue that for the moment the most sensible approach to dealing with climate change, at least as far as transportation policy is concerned, is to try and limit or cut back on car use through better public transport (its absurd that its cheaper to drive somewhere or fly than take the train!) By making cities more cycling and pedestrian friendly one can also reduce the need for motorised transport.

Figure 9, New Urbanism in Annapolis, Maryland [Credit:About.com]

As far as the car itself goes, I would focus on making them smaller, lighter and more fuel efficient, rather than trying to convert them all to an alternative fuelling system (at least until that alternative is properly developed and proven to work). Like I said, in the medium term some portion of the UK’s car fleet will be converted to electricity. But it will take a good few decades to complete this transition and I still won’t be surprised if they’re still outnumbered by petroleum powered vehicles in the 2040’s. So it occurs to me to be a good idea to make the best of a bad situation and make sure those fossil fuel powered vehicles are less gas guzzlers and more gas sippers.

Figure 10, The Loremo AG concept car which using a conventional 2-cylinder Diesel engine offers a performance of 157 mpg! [Credit: Treehugger]

Lighten the load

If we can’t get rid of all of the IC engined vehicles, then by just building them out of more lightweight materials, the engine size can be downsized and they become much more fuel efficient (a nice detailed article on this concept can be found here). Indeed this business of making cars more lightweight brings up some interesting facts as regards the theme of this article “why things change and why they stay the same“.

Using lightweight materials in cars is nothing new. Much of the chassis and body work of early cars of the 1900’s were made largely from wood. I was in a museum the a few weeks back and they had a car from 1928 which featured body panels made from fabric reinforced resin. So there is nothing that necessarily new about cars being made from materials other than steel. But as always there’s the issue of institutional inertia.

Steel is the world’s most common engineering material. It might be heavy and it might rust (of course if want to sell more units, building stuff out of a material that ultimately rusts isn’t necessarily a bad thing! see my article on the light bulb conspiracy for more on this). But steel is strong, reliable, dirt cheap, 100% recyclable and available in very large quantities. We have multiple grades and alloys of steel available to perform in practical any task you could name (the soviets even built their Mach 3 capable Mig-25 “Foxbat” fighters out of a lightweight grade of Nickel Alloy Steels).

With several centuries of practical experience under our belts, there is very little about steel and how it performs in different loading conditions and environments that we do not know. The car industry has built up many decades of detailed experience on how to use and manufacture cars out of it. By switching to a different material (Aluminium, fibreglass, composites, take you’re pick!) you’re essentially going to have to ditch much of that experience and wander into uncharted waters. For example many of those FEA models I discussed earlier would no longer be applicable, as the materials have different physical properties. Steel for example, like most metals, is an isotropic material while most composites are anisotropic.

Many materials have they’re own little quirks and traits that determines how parts are manufactured from them. Anyone wanting to know what I’m on about – try welding Aluminum sometime or take a diamond tipped cutting tool to a Cast Iron component, and you’ll soon find out! (safety disclaimer, no don’t!) There will be important differences in the manufacturing technology used to build such cars and this naturally produces a delay while factories are re-tooled and staff get retrained. And inevitably in the meantime costs go up as economy’s of scale are lost. Also there’s the pesky issue of maintenance. While composites don’t rust, they do “age” and degenerate over time. The last thing a car company wants is hundreds of thousands of cars falling apart after five years while still under warranty (now, after the warranty expires is another matter! See planned obsolescence).

Now don’t get me wrong, I’m not saying its not going to happen. Indeed, its already happening. Increasingly many “high end” cars are made from, or incorporate body parts made from composites (in particular sports cars). A number of high-end to mid-range saloon cars are already made from Aluminium, as are the engine blocks of many smaller cars.

Figure 11, The Lotus Elise boasts a Fibreglass body

I would therefore anticipate that, as the desire to make cars more fuel efficient grows, inevitably car companies will start to specify more and more production car parts out of lighter materials. This will eventually cumulate in entire vehicle chassis’s being made of composites and lightweight metal alloys.

In theory this could result in production cars with fuel economy in the order of up to 160 mpg (equivalent to a modern scooter!) without any significant change in power plant (other than the obvious, i.e. making it a lot smaller!). Such levels of fuel economy were achieved in the 2010 Automotive X-Prize, with some battery/electric and hybrid vehicles achieving the equivalent of 200-250 mpg. Although I suspect a 100-120 mpg car is probably the bottoming out point for any “proper” car of the future that we can envisage.

Figure 12, The Swiss made Monotracer is capable of 250 mpg in some advanced configurations [Credit Monotracer]

However, its important to emphasize that none of the changes I’ve discussed will take place overnight. This transition will take time, as the juggernaut that we call the global car industry will take decades to change course. Hence again why my focus would be on reducing the need for cars, rather than expecting overnight miracles with electric, hydrogen or low emissions vehicles.

Robot Cars

A theme throughout this article has been how the computer revolution has had an enormous impact on the car as we know. Perhaps the next logical step would be for the computers to take over the driving? Futurists have long predicted that with the advent of the robotic car (that being cars that can drive themselves), we could well find ourselves permanently relegated to the passenger seat.

Robotic cars offer numerous advantages, notably the fact that they don’t get drunk or distracted by the kids fighting in the back and run over old ladies, they provide better fuel economy and increased engine life (robots aren’t constantly sitting on the brakes and then speeding up or forgetting to change gear, etc.), they don’t get lost and refuse to look at a map, plus you can run robotic cars in bumper to bumper traffic at 70 mph!

Figure 13, Google’s self-driving car [Credit: Treehugger & Google]

Indeed robotic car technology has recently been progressing at quite a pace. The Google company have invested heavily in automated road vehicles based on the outcome of the DARPA challenge. The state of Califorina is now considering legalising the use of such vehicles on roads.

However, I would note that the major obstacle to the autonomous car is probably not anything to do with technology. We could automate lots of other things, such as passenger planes, but choose not too, as few are willing to risk their lives to a computer (bringing a whole new meaning to the term blue screen of death!).

Furthermore the experience of the aviation industry suggests that it may not be a terribly sensible idea. Computers then to go badly wrong, rather than just a little wrong. There have been a number of very serious accidents that have often occurred because the computer encounters a problem (sensor error, bad weather, a serious technical malfunction) trips out the autopilot or Flight Management System and the bored pilots are suddenly confronted by a serious problem which they then find themselves unable to solve.

The crash of an Air France flight 447 over the mid Atlantic a few years ago is a classic example. Accident investigations suggest that the disaster was caused by a minor sensor malfunction (loss of air speed indication) that the pilots compounded by failing to diagnose the problem early enough. And those pilots had ten minutes to try to figure out what was going on. Imagine if you’re on the M6 and the car’s auto pilot suddenly cuts out leaving you with seconds to figure out what’s wrong before you hit something!

Also, I suspect that it would not be sensible to operate autonomous cars anywhere but within certain fixed dedicated environments, motorways for example, where all the other vehicles also operated autonomously. Of course the problem there would thus be that you’d have to get everyone to install the automation technology before you could implement such a policy. There would also be a number of important legal questions to be answered (some of which are discussed here). Who, for example, is responsible at the time of an accident? The driver behind the wheel? (who was merely watching the car drive itself) or the vehicle manufacturer or the government? (for failing to maintain the road properly because the car hit a pot hole just before the accident).

While not quite “cars” driverless pods have long been proposed as a sort of “personalised public transport” solution. Just such a PRT (Personalised Rapid Transport) scheme using driverless pods now operates Heathrow airport, although these run on dedicated tracks. I’ve been hearing about such PRT systems for quite sometime, and while I’m not entirely convinced about them yet, certainly they could figure quite significantly in the future. If the price could be reduced and these pods developed such that they could run on the road network (even if only for short distances) this would truly close the loop between public transport and personal automotive transport (but I’ll believe that when I see it!).

Where’s my flying car!

While I would put the Fuel cell, autonomous car and PRT’s into the category of “maybe’s”, some things will always be pipe dreams. The flying car, a standard favourite of Futurists, is one of them. Why?

Figure 14, The flying car, the future of transport or pie in the sky? [Credit: Autoblog.com]

Firstly, there’s the matter of energy consumption. A car needs to only overcome rolling and air resistance to drive itself forward. An aircraft needs to lift its entire body weight off the ground (and overcome air resistance too!). Inevitably such a vehicle will have a much higher rate of fuel consumption than a car. For example, the range of energy consumption for a conventional car is between 40-80 kWh/100 km’s (somewhat higher for SUV’s, but let’s not go there!). The wide disparity is obviously due the range of car types we are discussing and whether we are considering cars that are full or only occupied by the driver. A helicopter is listed here with a fuel consumption rate of 11.9 Litres/100 km’s, which works out at 126 kWh/100 km’s (assuming 100% occupancy). So that would imply that flying by VTOL vehicles consumes at least 3 to 1.5 times more energy, than a car (and of course public transportation and offers even greater fuel efficiency, about a tenth or less the figures given for the car above).

It should be noted that some small aircraft can offer potentially good fuel economy, a 6 seater Cessna with an energy consumption rate of 60 kWh/100 km’s is listed here (slightly worse than our fully loaded conventional car). But any practical “flying car” will have to be capable of VTOL, otherwise they would needs runway’s and a dedicated airfield as you cannot have people performing take off and landing runs on conventional roads for what I assume are obvious reasons of safety. By its very nature VTOL aircraft will always have a worse fuel consumption than either a conventional aircraft or a helicopter. Indeed, a flying car will have an even higher rate of fuel consumption than a helicopter.

Many often don’t understand that modern aircraft represent a compromise between speed, fuel economy, ease of manufacture and ease of control. A flying car would by its very nature violate all of these rules. And to make matters worse fly lower, as many proposed flying cars it is suggested will do, will lose the fuel economy of cruising in the upper atmosphere (where the air pressure is lower, reducing air resistance). They would likely be slow (by aircraft standards), very expensive (compared to either car or comparable aircraft), deliver poor fuel economy and be harder to fly (than either conventional aircraft, helicopters or cars). These points are discussed in more detail by Popular Mechanics.

I would note that supporters of the flying car will often try to claim low fuel consumption by, for example, comparing their (largely untested) one or two seat vehicle made of lightweight materials to a standard SUV or large Sedan. Of course a fairer comparison would be with a small two seat car (such as a Smart car) or one of those ultra-light cars (100 mpg+) discussed earlier (or a motor cycle!). For the record on that point, smaller more fuel efficient cars go from 25 kWh/100 km’s (this would be a supermini) down to 6 kWh/100 km’s (that Loremo I mentioned earlier). A conventional electric car incidentally falls within a window of 15-21 kWh/100 km‘s, with lower values still for those X-Prize special’s I mentioned earlier. Inevitably once we apply a more fair comparison, it reveals a fuel consumption rate many times greater for the flying car (my guess would be an energy consumption level 5 to 10 times greater per passenger km).

However, its the control issue that I see as the major stumbling block. It takes most of us a couple of weeks of part time study to learn how to drive and past the test. Learning to fly requires intensive training (and quite a bit of maths!) lasting a few months. Getting a full pilots license takes even longer. And as I mentioned a flying car would likely be much harder to fly than a conventional aircraft. Aircraft of a different era, tended to have all sorts of dangerous quirks (spitfires for example were prone to a dangerous swerve on landing, P-38’s were prone to control lock ups via compressibility) which inevitably a flying car could well inadvertently pick up, as modern aircraft are designed they way they are as part of a deliberate effort to engineer such quirks out of them.

But it is VTOL aircraft, particularly any that relies on ducting fans (as it is often proposed flying cars will), that exhibit some of the worse control problems. Such vehicles tend to rate high on the Cooper-Harper scale (how test pilots rate the difficulty in flying a particular vehicle). The RAF’s most elite pilots were always the Harrier Jump jet pilots, the V-22 Osprey crew’s are probably now some of the USAF’s top pilots. In short, no flying car will ever be the sort of thing you’d be handing over to the control of amateurs. And let’s not even begin to consider the problem of air traffic control and thousands of unauthorised take-off and landings!

Finally there is the issue of the weather. Flying in the lower atmosphere is potentially dangerous in bad weather, due to the obvious consequences of cloud (impairing vision) and winds, as well as ice formation. Typically modern aircraft try to avoid flying low and climb as quickly as possible to a higher cruising altitude to get around these problems, as well as due to the greater fuel economy gained from flying at higher altitudes. In essence any fleet of flying cars will likely be inoperable at the very time they are most needed (bad weather days!).

Inevitably, very few if anyone would have the piloting skills or finances (nor stupidity!) to use such a vehicle. There are some niche roles where they may be used – forest rangers, ranchers on large country estates or the military (although it should be noted the military have tried developing these vehicles a number of times and generally learnt they are a bad idea and cancelled such projects!). But ultimately it makes more sense to stick with existing helicopters and fixed wing aircraft technology and just get a bus to/from the airport!