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The paper you posted was talking about the apparatus creating a beam of fragments, millions of them, after the nuclear device had shattered the plate. Now, the only relatively small object (900kg) that I know to been driven by a nuclear bomb the way you want to is the infamous "manhole cover i...

Basically, if you take a four thousand ton system and try to replace its heaviest component with a one ton object, removing the entire rest of the system... The resulting system is not going to respond in a simple or linear fashion. One cannot simply say "this accelerates four thousand tons by...

Things made out of atoms do not remain intact when heated to tens of thousands of degrees. When the energy per atom is large compared to the binding energies tying the atoms together, they will fly apart, one way or another. Oh, the plate itself does not reach the temperature of the plasma pushing ...

Edit privileges on this forum are extremely restricted, so I'd be pleasantly surprised if it were possible to do so. Sorry, was being sarcastic. Other key questions- is the plate's material dispersed laterally into an expanding cone? Given that it's vaporized, this can result in huge losses of effi...

jwl wrote:As I said, if E is energy density, you didn't plug that in, you plugged in energy on its own. Although actually energy density would fail dimensional analysis too, what wouldn't would be specific energy.

Would you like me to continuously update the original post to reflect the ongoing discussion?

I think I see where the confusion over the 85% is coming from. That's the efficiency of the Orion pulse units, and the Casaba charges described in this paper have a different design from the Orion units. It looks like the design described in the paper is attempting to shape the actual burn wave to ...

That document is about nuclear shaped charges, and the concept of shaped charges is a bit different from epf. Enough to matter. Sea Skimmer is the guy who knows about it, he briefly discussed this once here on the board. Also - it usually means that there is some back plate to direct the charge. Th...

Personally? I'd ask a real rocket scientist or plasma physicist. I would ask a nuclear physicist as well, just to be on the safe side of things. Especially since the first stage of major energy loss is in the efficiency of the actual reflection/focusing of radiation into the filler via the casing. ...

Simon_Jester wrote:Personally? I'd ask a real rocket scientist or plasma physicist.

They seem to be in very short supply these days.

I don't think that anybody ever did any work on how to form a kinetic penetrator by setting off a nuke. http://scienceandglobalsecurity.org/archive/sgs01fenstermacher.pdf Pages 204-206 Matterbeam is just running amok with a known formula, and substituting "explosive" with the biggest bang...

85% thermal efficiency is derived from Atomic Rocket's entry on Orion Pulse Propulsion, itself citing from GA-5009 vol III "Nuclear Pulse Space Vehicle Study - Conceptual Vehicle Design" by General Atomics (1964) ( https://web.archive.org/web/20070704104944/http://ntrs.nasa.gov/archive/na...

The equations for explosively formed projectiles are not applicable here. EFP warheads do not vaporize the liner, whereas a casaba howitzer or Orion charge unit does vaporize the entire assembly including projectile liner. Standard shaped charges are also too dissimilar due to the energies involved...

Can you link to that study? Also, the reason you can't find estimates of heat capacities at those temperatures is that plasmas behave very differently from ordinary states of matter and don't necessarily fit neatly into the equations you're accustomed to. I confess I've forgotten pretty much all my...

1) A flyer plate warhead isn't an EFP, no deformation of the plate is required for it to function correctly. 2) Equation is not really valid for the purpose you are attempting in general; among other problems the equations are never valid for extreme situations in charge to liner energy-mass. That ...

Looked up the equation because it looks fishy due to failing dimensional analysis. It turns out E does not stand for energy, it stands for the Gurney constant. I see. I thought it was a function of energy density. How would I go about determining gurney constants of explosive fillers containing X j...

I'm not qualified to say if your scenario with the switched components would work the way you imagine it would, but could you please write down your equations and how you solved it to get these numbers. coming up with a number that is 10 times of a number that seems sensible (2.6TJ kinetic for 3.56...

Hello! I'm having trouble with a set of equations meant to describe the velocity of an Explosively Formed penetrator, called the Gurney equations. Specifically, the kinetic energy delivered by the explosive charge, and the kinetic energy contained in the EFP, do not add up. Here is the set-up: https...

A few notes I'd like to make: 1) Drones vs Humans: Having humans inside space warships depends entirely on mission duration and the mass ratio impact of a human and their life support. It has nothing to do with how 'large' a spaceship is. For example, a 10 ton drone will outperform an 11 ton manned ...

Honestly, we've been able to spot problems with each proposal so far even on a statics level, or a VERY informal dynamics level. Problems like "accelerating one end of a rope doesn't magically accelerate the other end of the rope to the same velocity" or "the payload can't withstand ...

The forces are so gigantic tuat you most likely reach the lomits of elasticity well before the dampening system can react. (You are well beyond subsonic speed within the materials, which usually means shattering.) You will need to design payload hull, connection to tether, tether and bolt connectio...

[Attempts to be patient...] Then why... did you think you needed a railgun? [Will respond to rest of post shortly] I didn't go back and review the entire design after adding modifications further down the line. The first design used a gun-barrel type gas brake, where compressed gasses increased in ...

Still not getting why the railgun needs to be included. You have a 28kg hook with drone at 0 m/s. You have the tether end with the railgun and airbags moving at ~7300 m/s. You fire the railgun to bring the (as you say - 1kg) heatshield to 0 m/s. The hook and the heatshield dock at 0m/s. Heatshield ...

I'm just wondering how you get a cloud of free-floating gas in space, without it disappearing in all directions at the speed of sound. Well, I'm also wondering about the precision timing on the launched parts hitting the apogee of their trip at exactly the right time. There's a very small volume of...

parasitic mass for current config contains 1 heatshield, 1 thether and hook of unknown properties, a drone, replacement gas bags and gas filling, spareparts for the railgun, fuel to provide energy for rail gun, fuel to reorbit station, spareparts for the pulley system and station provisions for ope...

I'm afraid this doesn't help very much. The fundamental question is: How do you connect the 'main' tether to the payload, so that the station can bring the payload up to speed by exerting force on the tether? This is a question that should not require four diagrams to answer- at worst, it should re...