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Continued! Steam Cannon successful at MIT! http://web.mit.edu/2.009/www/experiments/steamCannon/ArchimedesSteamCannon.html http://web.mit.edu/2.009/www/experim

by Isamu 7y ago

Continued! Steam Cannon successful at MIT! http://web.mit.edu/2.009/www/experiments/steamCannon/ArchimedesSteamCannon.html http://web.mit.edu/2.009/www/experiments/steamCannon/Archime... >Being frustrated with the outcome, having a visit to MIT in their schedule, and remembering last year’s Archimedes’s death ray collaboration, the MythBusters asked us to take a look. They wondered if there was a simple, plausible solution compatible with da Vinci’s vague drawing and explanation of Archimedes's steam cannon. >The drawing has been interpreted as a direct injection concept, where water rapidly sprays into a hot breech and the resulting flash of steam launches the projectile. >But, some back-of-the-envelope calculations suggest otherwise. A 540 °C (1000 °F) copper breech can provide a heat flux of roughly 100,000 kiloWatts per square meter to water that is in direct contact with its surface. And if water can be sprayed onto the breech in a uniform 1mm thick layer, 2,000 kiloJoules of energy per square meter of surface will produce 400 PSI steam—a pressure that would generate a reasonable projectile velocity. [...] >High-speed camera footage showed that the muzzle velocity was over 300 m/s (670 mph)! >We can’t say if Archimedes did it, but this small-scale test shows that a simple, powerful steam cannon could probably have been made using technology of his era.

jandrese 7y ago
Very frustrating that they didn't share the actual working solution. The most obvious would be to line the interior of the firing chamber with metal spikes or some sort of texture to increase the surface area so you have more water spray in direct contact with the hot surface at once. Also, increasing the pressure of the spray so more of it gets to the sides before the steam starts building and insulates it. It's clear the injectors need to be running at a fairly high pressure if you're going to be vaporizing half a cup of water in a few thousandths of a second.
Iv 7y ago
I keep being amazed by all the purported inventions of Archimedes. And disappointed by the hubris of modern engineers who think that it should only take a handful of interns and an afternoon to reproduce what would have been at the time cutting edge military research, with a lot of ingenuity invested in it. Someone who would invent the anti-naval claws, the sun death rays and a steam cannon would not have just one clever invention in making each work. The solar death ray requires aiming devices and thousands of people. I find it very interesting that nowadays we can make almost perfect mirrors compared to the maybe 50% reflective bronze shields they would have had but producing a few thousands and making a few thousand people collaborate is something we have a hard time reproduce.
- wincy 7y ago
  I’m not sure I’d call “forcing a bunch of slaves to hold up mirrors” “collaboration”.
  - Iv 7y ago
    We don't know much about Syracuse politics, but in that case, it is more likely this was done by soldiers. Syracuse garrison would have been at least a thousand troops and more probably several thousands. While waiting for the ships to land, it sounds like a good idea to try and sync them to try make the ships catch fire.

by Isamu 7y ago

jandrese 7y ago

Very frustrating that they didn't share the actual working solution. The most obvious would be to line the interior of the firing chamber with metal spikes or some sort of texture to increase the surface area so you have more water spray in direct contact with the hot surface at once. Also, increasing the pressure of the spray so more of it gets to the sides before the steam starts building and insulates it. It's clear the injectors need to be running at a fairly high pressure if you're going to be vaporizing half a cup of water in a few thousandths of a second.

Iv 7y ago

I keep being amazed by all the purported inventions of Archimedes. And disappointed by the hubris of modern engineers who think that it should only take a handful of interns and an afternoon to reproduce what would have been at the time cutting edge military research, with a lot of ingenuity invested in it. Someone who would invent the anti-naval claws, the sun death rays and a steam cannon would not have just one clever invention in making each work. The solar death ray requires aiming devices and thousands of people. I find it very interesting that nowadays we can make almost perfect mirrors compared to the maybe 50% reflective bronze shields they would have had but producing a few thousands and making a few thousand people collaborate is something we have a hard time reproduce.

wincy 7y ago
I’m not sure I’d call “forcing a bunch of slaves to hold up mirrors” “collaboration”.
- Iv 7y ago
  We don't know much about Syracuse politics, but in that case, it is more likely this was done by soldiers. Syracuse garrison would have been at least a thousand troops and more probably several thousands. While waiting for the ships to land, it sounds like a good idea to try and sync them to try make the ships catch fire.