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Registered Member #49
Joined: Thu Feb 09 2006, 04:05AM
Location: Bigass Pile of Penguins
Posts: 362
In terms of kinetic energy transfer, single stage, which type of coil gun could be considered the most efficient. I don't care about velocity, only efficiency, so if need be assume an optimal projectile for each type, even if said projectile is 20 pounds.
As far as I know, disk launchers and thompson rings are just induction launchers. Fastmhz has managed to get almost 10% efficiency with pancake coil induction launchers. I haven't got more than 2.3% efficency with reluctance coilguns.
I had a good look at the 6% efficient coilgun, and there are two technical discrepancies. One is that "initially it fired a 30mm round at 27 m/s" on 47 J energy? and the only projectile that it described is a small nail. Also when I made the coil with barry's inductor sim and used the specs for an RLC circuit I got a pulse that goes on for over a second. Some of the specs (or my interpretation of them) could be wrong, but it seems very fishy to me.
Registered Member #1525
Joined: Mon Jun 09 2008, 12:16AM
Location: America
Posts: 294
That "PAR I" looked a little fishy to me too, but reluctance coilguns can get up to 15% efficiency for hobbyist designs, probably more if you tried hard enough. The trick is to use low voltage, enhanced flux linkage, proper switching/quenching, and multiple coil stages stages.
Registered Member #49
Joined: Thu Feb 09 2006, 04:05AM
Location: Bigass Pile of Penguins
Posts: 362
So if I was going to build an induction launcher (pancake, for example) with the goal of efficiency, I'd want a thick, highly conductive, projectile, no?
Registered Member #1451
Joined: Wed Apr 23 2008, 03:48AM
Location: Boulder, Co
Posts: 661
You'd want one that wasn't much thicker than the skin depth at the frequency of your pulse. You want to optimize velocity as the energy increases due to it's square, so a thicker projectile wouldn't help you out.
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Which type of coilgun is the most efficient?
