- #1
xpell
- 140
- 16
After reading a lot about railguns, light gas guns and other approaches to build an hypervelocity/hypersonic cannon, I wonder why the "centrifugal cannon" option hasn't been more thoroughly explored by any military power in the world. Yes, I know the old versions had a precision problem and were unreliable, but I can't see how this couldn't be corrected using modern technology. Sure there must be an obvious reason, but my ignorance doesn't let me grasp it. Please keep with me for a minute:
Let's build a cylindrical vacuum chamber with an inner diameter slightly over 2 m, on a gimbal to provide for azimuth and elevation. Inside, we install a well-balanced disk 2 m in diameter and an engine (or transmission, or magnetic engine...) able to make it spin at 250,000 rpm (like not a few turbochargers or even heavier industrial machinery.) Up to this point I can't see anything intrinsically impossible or even too expensive or complicated. Any ship and even probably some large airplanes could handle this.
OK, now let's load a projectile on the border of the disk and spin it up. At just 20,000 rpm, the linear/tangential velocity of this projectile will already be fully hypersonic at sea level: over 2 km/s. At 75,000 rpm, it's close to 7.9 km/s ---Mach 23, almost ground-level orbital speed at Earth's equator! At 125,000 rpm, the rotational speed of a lame turbocharger, it's 13.1 km/s ---way over Earth's escape velocity. If we go up all the way to 250,000 rpm, we get over 26 km/s, over Uranus' escape velocity. Since it's spinning in a vacuum, aerodynamic forces, drag and heating are nil. With proper refrigeration at any other source of heat, you could possibly keep it running for awhile until the appropriate moment to attack.
So just choose your rotational speed, azimuth and elevation and make a precise computer-controlled system release the projectile at the appropriate instant. Maybe we'd need a system of locks to transfer it from vacuum to atmosphere without damage, and/or a final but simple magnetic "drive" for extra precision. And we have a projectile streaking towards its target at highly hypersonic speeds. Sure, the accelerations are going to be hellish, but that is expected in most if not all hypervelocity designs. I feel this could be way "simpler", maybe more robust and ultimately more inexpensive than railguns, etc. Additional acceleration-resistant on-board guidance maybe could be developed for a second stage of such project, just like they're trying with "conventional" approaches.
Sure this is going to be impossible, unfeasible, far-fetched and/or plainly ridiculous by some reason(s), since nobody seems to be doing it and certainly I'm not smarter than the top military engineers around the world. But... would you help me to understand these reasons, please?
(If you think the higher rotational velocities are too far-fetched, please keep it under 50,000 rpm; Zippe-type uranium centrifuges need at least 90,000 rpm and they've been manufactured for ages, that's '50s tech. Or even lower rotational velocities with a larger disk diameter ---in both cases, we'd still have vastly hypersonic speeds above 5 km/s, around Mach 15.)
Let's build a cylindrical vacuum chamber with an inner diameter slightly over 2 m, on a gimbal to provide for azimuth and elevation. Inside, we install a well-balanced disk 2 m in diameter and an engine (or transmission, or magnetic engine...) able to make it spin at 250,000 rpm (like not a few turbochargers or even heavier industrial machinery.) Up to this point I can't see anything intrinsically impossible or even too expensive or complicated. Any ship and even probably some large airplanes could handle this.
OK, now let's load a projectile on the border of the disk and spin it up. At just 20,000 rpm, the linear/tangential velocity of this projectile will already be fully hypersonic at sea level: over 2 km/s. At 75,000 rpm, it's close to 7.9 km/s ---Mach 23, almost ground-level orbital speed at Earth's equator! At 125,000 rpm, the rotational speed of a lame turbocharger, it's 13.1 km/s ---way over Earth's escape velocity. If we go up all the way to 250,000 rpm, we get over 26 km/s, over Uranus' escape velocity. Since it's spinning in a vacuum, aerodynamic forces, drag and heating are nil. With proper refrigeration at any other source of heat, you could possibly keep it running for awhile until the appropriate moment to attack.
So just choose your rotational speed, azimuth and elevation and make a precise computer-controlled system release the projectile at the appropriate instant. Maybe we'd need a system of locks to transfer it from vacuum to atmosphere without damage, and/or a final but simple magnetic "drive" for extra precision. And we have a projectile streaking towards its target at highly hypersonic speeds. Sure, the accelerations are going to be hellish, but that is expected in most if not all hypervelocity designs. I feel this could be way "simpler", maybe more robust and ultimately more inexpensive than railguns, etc. Additional acceleration-resistant on-board guidance maybe could be developed for a second stage of such project, just like they're trying with "conventional" approaches.
Sure this is going to be impossible, unfeasible, far-fetched and/or plainly ridiculous by some reason(s), since nobody seems to be doing it and certainly I'm not smarter than the top military engineers around the world. But... would you help me to understand these reasons, please?
(If you think the higher rotational velocities are too far-fetched, please keep it under 50,000 rpm; Zippe-type uranium centrifuges need at least 90,000 rpm and they've been manufactured for ages, that's '50s tech. Or even lower rotational velocities with a larger disk diameter ---in both cases, we'd still have vastly hypersonic speeds above 5 km/s, around Mach 15.)
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