Homeland Security's worst nightmare.

[Patroklos]

That engine idea is interesting, but I don't see them reaching the performace levels of metal engines any time soon, the ceramics just can't handle the pressures.

[dannubis]

Cermics are much harder and lighter than metals.

Therein lies their main weakness: because they are so hard they break easy under shock type of loads.

So they would indeed not be the material of coice to make an engine.

However, ceramics can withstand much higher temperatures than metas and are much lighter, meaning that any ceramic engine will be a much more efficient than a metal one.

Several car makers have developed ceramic engines that work perfectly fine. Only, would you put an enigne in a car of which you are not sure that it can withstand 20 years of abuse of the average John Doe ?

[Dinner]

Originally posted by MarkG
how did you explain to your boss when he found out you were looking on the interweb for ceramic engines?

Haven't told him and don't intend to tell him.

[Dinner]

Originally posted by Patroklos
That engine idea is interesting, but I don't see them reaching the performace levels of metal engines any time soon, the ceramics just can't handle the pressures.

Supposedly ceramics made of zirconias are almost as strong as steel. As an added benefit they are extremely heat resistant so you wouldn't need to water cool it which is another weight saver. You'd just need oil to keep things moving smoothly.

This actually seems like you could almost use the same engine but have it weight 1/3 of a steel engine. Sure, some parts would still have to be metal but that's a lot of weight savings right there. Imagine of you replaced the car's steel frame with aluminum & magnesium, the sheet metal with plastic panels, etc... We're talking a car the same size but weighting a whole lot less thus improving performance and fuel economy.

[Patroklos]

Imagine of you replaced the car's steel frame with aluminum & magnesium, the sheet metal with plastic panels, etc... We're talking a car the same size but weighting a whole lot less thus improving performance and fuel economy.

Sounds like a death trap

But seriously, I like this direction and I hope they work on it to make it practical. Even if they get it to work, it sounds like the fabrication requirements will make the ticket price eat up any fuel economy savings and then some as things stand right now. Time will change that.

[Lord Avalon]

So ceramic engines can run very hot. What I would be interested in is how such an engine handles a very cold winter - or rather a series of very cold winters.

[dannubis]

Theoretically, no problem, because their thermal expansion coefficients are much lower than those of metals.

[Dinner]

Originally posted by Lord Avalon
So ceramic engines can run very hot. What I would be interested in is how such an engine handles a very cold winter - or rather a series of very cold winters.

Everything works identical (or so I would imagine) except ceramics are extremely good insulators (especially foamed ceramics) because they're mostly air bubbles encased in a crystal matrix. That means heat or cold has a hard time passing through the ceramic.

[Kirnwaffen]

Honestly, ceramics are just one among many, many nightmares for the TSA. I know some of guys that used to do airport security testing, and what they were able to get through security was disturbing. Pretty much, most of the makeshift weaponry that you see made in prisons get through. The terrorist/criminal types are just more creative, it seems, than many of our security professionals.

[Patroklos]

I think it has more to do with the fact that the terrorists types only have to succeed once, your average TSA agent has to succeed several thousand times a day.

[onodera]

I've managed to carry a metal knife on board once. Found out I had it with me only in the hotel room.

[dannubis]

Originally posted by Oerdin


Everything works identical (or so I would imagine) except ceramics are extremely good insulators (especially foamed ceramics) because they're mostly air bubbles encased in a crystal matrix. That means heat or cold has a hard time passing through the ceramic.

That would be bad as it would generate internal stresses in the egine itself.

They are of course better insulators than metals but the main point is the low alpha.

[dannubis]

Originally posted by onodera
I've managed to carry a metal knife on board once. Found out I had it with me only in the hotel room.

I find it exceedingly annoying that you are almost stripped to the bone when boarding the plane but once on it in business class you get metal knives to eat your food.

I mean, WTF ?

[Kirnwaffen]

I agree that there is a volume issue, but I think it's also a training issue, as well as a technology issue. As far as these guys could tell, agents weren't necessarily trained to identify the kinds of non-standard objects that terrorists and criminals are likely to resort to now that things like knives and box cutters are more easily identified.

In addition, the detection capability we have is very limited (metal detectors, obviously, only "see" metal; top down X-ray means that objects positioned a certain way won't be seen). One of the other major threats out there, on par with ceramics, is carbon fiber. As one of them mentioned, "You could take a carbon fiber sword onto a plane, and nobody would catch you".

[Monk]

Originally posted by dannubis


I find it exceedingly annoying that you are almost stripped to the bone when boarding the plane but once on it in business class you get metal knives to eat your food.

I mean, WTF ?

You've got a source for that? I flew to Newark on Scandinavian Airlines business class recently, and I do believe those knives weren't sharp. People essentially ate their beef with butter knives.

I do remember a steak house at Copenhagen Airport removing their sharp knives for this purpose though, after a journalist took a steak knife to the gate and wrote about the pointlessness of him being able to do that while getting nail clippers confiscated at security...