TallDave wrote:It seems very unlikely you will ever see Polywell fusion in small mobile applications. I would say the lower limit is probably something like a Navy destroyer (~100 tons).
Not to quibble, but a Destroyer is about 3000-5000 tons. Some have even been as large as 7000.
100 Tons is a small patrol craft.
True, I guess I was just thinking of the lower limit on destroyer weight being something like the first destroyers (something around Daring class). I think ~100T is about as light as any destroyer ever was, although probably no one has made any that small in a long time. Modern ones get about 100x times that mass (Zumwalt class).
It's hard to imagine a Polywell power system fitting on a 100T craft, or a locomotive. It stretches the bounds of physics to imagine one powering anything on a roadway.
It does look like it would fit nicely on a modern destroyer:
The DDG-1000 is planned to feature: a low radar profile; an integrated power system, which can send electricity to the electric drive motors or weapons, which may someday include a railguns[5] or free-electron lasers;[6] total ship computing environment infrastructure,
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
Modern destroyers are typically ~10,000 long tons, though I would go ~6,000 to 10,000. The DDG1000 is more sized like a Light Cruiser at ~14,000 long tons, which may be why it will be a Class of 3. 3,000 to 5,000 is Frigate size. IMNSHO.
Last edited by KitemanSA on Tue May 18, 2010 8:34 pm, edited 1 time in total.
OTOH, it wouldn't surprise me if we never saw a PW on anything smaller than a supercarrier, perhaps next to a fission reactor, given that they may need tens of MW of continuous power input.
I guess it depends on what you're buying: power density, ultrahigh specific impulse (no refuelling), low cost, lack of nuclear waste, or some other factor.
Last edited by TallDave on Tue May 18, 2010 3:43 pm, edited 3 times in total.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
"It stretches the bounds of physics to imagine one powering anything on a roadway. "
Remove the roadway, and the power levels would suit a monster drag-line or similar excavator. Okay, they'll still need that kV power-cord, but it beats trailling pylons to the back of where-ever...
Fusion powered open-cast mining ?? Why not !! It would certainly minimise the carbon footprint !!
TallDave wrote:OTOH, it wouldn't surprise me if we never saw a PW on anything smaller than a supercarrier, perhaps next to a fission reactor, given that they may need tens of MW of continuous power input.
10MW is only 13,000 hp. This is about the size of one of the main propulsion diesel engines on the LPD-17 Class. The LM 2500 turbine on the FFG-7 Class is 25 MW and the FFG-7 has two of them. Seems either engine could be used to start up the reactor which could be self supporting thereafter.
Thus it seems the FFG-7 might make use of a polywell, and it is WAY smaller than a supercarrier! The only question would be what to do with all that power! Lasers? Railguns? Huge honkin radars? Provide them and they will be used.
I have advocated several times for the first test platform for Polywell Afloat be an FFG-7. The space is there, and it is easy to modify. Plus, now that we are decomming the remaining units over the next 4 years, it makes getting a hull to play with very easy.
They could even use it as an electric drive validation testbed.
Plus you have four SSDG's to use for initial startup power for the Polywell.
I'm tellin y'all, seems like a winner for proof of marine concept...
TallDave wrote:OTOH, it wouldn't surprise me if we never saw a PW on anything smaller than a supercarrier, perhaps next to a fission reactor, given that they may need tens of MW of continuous power input.
10MW is only 13,000 hp. This is about the size of one of the main propulsion diesel engines on the LPD-17 Class. The LM 2500 turbine on the FFG-7 Class is 25 MW and the FFG-7 has two of them. Seems either engine could be used to start up the reactor which could be self supporting thereafter.
Thus it seems the FFG-7 might make use of a polywell, and it is WAY smaller than a supercarrier! The only question would be what to do with all that power! Lasers? Railguns? Huge honkin radars? Provide them and they will be used.
True, if you're looking for power density or cost. OTOH if you're looking for specific impulse for long missions without refuelling, you might not want to carry around traditional petroleum fuel, and we're not really sure yet where the lower end of PW feasibility is going to end up, or how much it's going to cost.
I do love the idea of Polywell-powered railguns.
n*kBolt*Te = B**2/(2*mu0) and B^.25 loss scaling? Or not so much? Hopefully we'll know soon...
