Post scripts: flying cars and seat belts with air bags

One of the things I was thinking about when I started work on the "towards a safer light aircraft" idea was a plane that was similar to a car to drive. The controls are different - they have to be, to some extent, but one of the features of having wings in a hexagonal shape that I was going to try and work on (probably by having the ailerons in the lower part of the shap larger than those in the upper) is to try and get the correct bank for a turn automatically (this is obviously not a design for advanced flying!)

Interstingly, someone has now come up with a car that can, by means of folding wings, convert to a plane. See http://www.terrafugia.com/, and http://www.theage.com.au/drive/motor-news/flying-cars-closer-to-reality-20091113-idqt.html. The cruising speeds are OK: 185kmh in the air, and 100 kmh on the ground.

On another topic, someone has developed a seat belt with an air bag: see http://www.theage.com.au/drive/motor-news/seatbelts-with-airbags-20091113-id9y.html. That's a good alternative to my "Increasing G absorbance of seat mounts" post. All we need is for someone to start applying car safety technology to planes.

Oh, that's what the inventors of the flying car have started doing ....

A possible better use of supertankers?

Supertankers are a highly contentious matter. They are a highly visible, concentrated risk way of transporting a dangerous, environmentally damaging material. There are arguments that it is easier to manage the risks by having them in well designed place: maybe that is true, but when things go wrong (e.g. Exxon Valdiz), they go wrong in a big way.

Be that as it may, that's not the topic I wish to write about here.

The idea of a vessel's life cycle is (generically) that, when a vessel exceeds it's useful life, it is scrapped, and the materials reused. That's good from the point of view of conserving materials, but it involves a significant amount of energy, and, as I understand it, very considerable risk to some workers in places like Chittagong, India. If another use could be found for a vessel like a supertanker, one that delayed the need to scrap it, that would save quite a bit of energy consumption.

I have also seen pictures/documentaries at various times over the last few decades of large fleets of temporarily decommissioned ships, including supertankers. I think I first saw this in the 1970s, during the oil crisis then - it looked a bit like some of the aircraft boneyards, but with massive ships rather than planes. Are all tankers/supertankers currently being utilised, or are some idle, doing nothing but deteriorating and/or costing money? If so, could they possibly be put to use via other means?

The other comment that contributed to my thinking on this was a comment I heard on ABC's Radio National about renewable energy, when someone said a relatively small area of Australia (something like 50km x 50km) could be used to provide energy by solar means for Australia AND also enough to export to south east Asia.

(As an aside, because of the materials used in photovoltaic cells, I consider using solar heat a better way of getting energy from the sun, even if it is a lower efficiency.)

So ... what if some supertankers could be converted to large batteries? Would it make sense - from an energy balance point of view - to use the solar generation capability in parts of WA, and perhaps some of the shipping facilities associated with the iron ore and other mining industries there, to charge a supertanker, and then send it to wherever it was needed, to hook into the power grid and provide renewable energy?

The energy involved in moving the mass is obviously going to be a consideration, as are the ways that the ship would be converted to a battery. Can this be done efficiently (or efficiently enough) and without creating a different environmental risk, or a different set of damages to the environment (with respect to obtaining suitable materials)?

Most electrical power transmission is via grids using cables, which can be laid across ocean floors, but that is expensive, damaging to some extent to local environments, and prone to damage from earthquakes (and we are all now well aware of the potential for such damage from the Asian tsunami - actually, maybe this could be used for disaster relief, by providing a large source of power if power girds can be repaired enough).

Would a converted ship be safer?

I don't know. Would the charge make the ship more susceptible to lightning strikes? Would discharge of the charge if the vessel sank kill the crew and marine life for some distance?

The type of technology used would be crucial.

Car batteries are lead-acid batteries: they aren't going to be suitable. Gel batteries or similar involve less risk of spillage, but maybe they could potentially still be damaging if the ship sank.

Lithium ion batteries are, I understand, the most efficient form of battery in that the highest power density. However, they're mostly used for small applications: would they be impracticable (e.g. weight, cost, risk) for this sort of large application? I suspect so.

Maybe molten salt batteries are more appropriate.

Maybe new technology would have to be invented, possibly including the use of parasails as is starting to be the case on some large cargo vessels.

It's all just a thought :)

Better cooling of cars

One of the best ways to keep a car cool on a hot day is to park under some shade. Well, why not carry some shade around with you?

My idea here is to provide a double layer of steel on the roof, with the space between open to the air. When the car is parked, this space would heat up first and, with appropriate vents in the top, allow some of the heat to flow out with rising air, rather than go into the car interior.

Of course, this involves additional material, so there is a trade off between saving in reduced load on air conditioning etc vs. extra energy in mnufacturing the extra steel. Safety may be an issue, given that some people seem to still leave children or small animals unattended in closed vehicles (see my post "Better operation of car airconditioning").

I consider it may also be possible to use the heat transfer via compression/expansion that I posted about in "No refrigerant cooling" in the spaces between the two roof layers. I'll aim to get some sketches on this developed over the next few months and posted.

Better operation of car air conditioning

The air conditioning in cars is basically a heat pump: heat is transferred from the interior of the vehicle to the outside environment. To do so, energy is consumed - the air conditioning basically increases the load on the car's engine, and thereby increases petrol consumption. Now, I have a few thoughts on how to minimise the build up of heat inside cars, but I'll save that for another post. What I would like to cover here is a more rational way of using air conditioning.

Now, a parked car on a hot - or even warm - day will act as a greenhouse. The effect of the sun will be to heat the air inside the car (and direct radiant heat will further increase any exposed surfaces), and thus heat the seats and anything else inside (which is why it is a criminal offence here, in Victoria, to leave a child unattended in a car (they will heat up more quickly than an adult: think of cooking something in your oven - a smaller object can be cooked quicker, if temperatures are the same [don't like the analogy? Good - that is exactly what people who leave children and animals in cars on warm to hot days are doing), although it is also an offence to leave a child under 15 without adult supervision.

Now, when you go back to your parked car, if you get in, leave it all closed up and then start the engine and the air conditioning, the load your air conditioning has to deal with is:
- the accumulated heat in the interior
- the heat in the air
- the additional heat being put out by the initial air flow from the air conditioner

The second point of these can be dealt with quite easily: turn the fan on high, and open doors or at least windows for a couple of minutes (you should run your engine for at least 30 secionds to get oil circulating before you start driving anyway). For your personal comfort, you can do this while standing outside.

The third heat load is the one that bugs me most. So many people idiotically turn on the air conditioning, and think they MUST close everything up immediately or the air conditioning won't work.

RUBBISH!!!!

If you do close everything up immediately, all you are doing is adding the heat load of the initial warm air that is coming out of the air conditioner to the laod that has to be dealt with by the air conditioner. So, after it deals with the hot air that was in the car initially, it then has to deal with the extra heat load that comes out of the vents when the air conditioner was turned on. You are, in fact, initially INCREASING the air temperature, and then extending the time that will be taken to cool the car. (Of course, this also increases the amount of petrol consumed, and the environmental damage done.)

It's actually quite simple: is the air coming out of the vent warm or cool? If it is still warm (and it can take a few minutes for some air conditioners to start working effectively), then LEAVE THE WINDOWS OPEN.

When the air feels cool, THAT is the time to start closing the car up!

Beaten to the punch: improved protection of military personnel carriers

One thing I can never see myself getting involved with is military design. Apart from not having any training or experience in military matters, I have grave ethical concerns about the on-selling of surplus defence materiel, and some of the overseas wars we have been involved in .

Having made that point, I have, however, idly speculated about some defence related matters - such as how to make more effective armour on personnel carriers. My thoughts were along the lines of providing funnels to direct blasts from mines upwards and through a more armoured area of the vehicle (picture, if you will, something like a hummer with, say, four pipes going upwards through the vehicle and angled armour below - a bit like the South African defence vehicles with the massive "keel" underneath them from the days when the evil apartheid regime was in power), protective areas around each crew member/passenger (a bit like the seat armour that used to be used on fighter pilot seats during he Second World War). I had speculated that, maybe, the thing to do design wise was to design the vehicle to be able to take enough blast to be able to be turned over/lifted: however, that isn't likely to work because of the speed of the blast wave.

I'd also thought about using some sort of electromagnetic field to deflect bullets or shells, but that is likely to involve a massive electrical source, probably most effective against relatively light weight projectiles (i.e. bullets) for which effective armour already exists. (Some of the armour available on tanks is quite ingenious - such as reactive armour, and someone has come up with "electrically charged armour".)

However, I've been beaten to the punch. Someone has designed a vehicle where there are protective cupolas for the crew/passengers, and good armour.

I thought I had saved the link, but now I cannot find it. Darn.

Oh well, here's a few links that might be of use:

• Australian troops offered new ride: the Hawkei AAP, via "The Age" September 29, 2009
  
• Battle on to build safer war vehicle Brendan Nicholson The Age September 30, 2009