Explosions Question

Post by **Surlethe** » 2006-04-16 09:31pm

For a personal project, I'm looking into researching and modeling the conditions inside an explosion. Can anyone recommend a textbook or two as a starting point? I'd very much appreciate it.

Winston Blake · Post by **Winston Blake** » 2006-04-17 03:37am

The best reference i can do: http://www.theforce.net/swtc/bang.html

Post by **Darth Wong** » 2006-04-17 03:59am

That is for fireball expansion in an ideal gas. A useful piece of information to be sure, but if you're talking about explosions in solid objects, ie- explosions of spaceships and such, it won't work.

Post by **Surlethe** » 2006-04-17 08:04am

I'm looking for more general information on explosions, mathematical models, and -- to be frank -- I don't think this is something I could master from a website, hence the request for textbooks in the OP. I'm specifically interested in modeling the interior of an explosion, because I have some ideas about Alderaan's demise, and I want to test them against the movies.

Dooey Jo · Post by **Dooey Jo** » 2006-04-17 08:28am

I think most explosions are usually modeled through fluid dynamics, so you might want to read up on that. Since the Alderaan explosion was achieved through a chemical explosion (special effects-wise, of course), it could probably work quite well. I can't name any good text books though, as I have never studied fluid dynamics and therefore I don't think I'm qualified to say what's good and what's not...

Post by **Darth Wong** » 2006-04-17 12:22pm

The Sedov solution assumes ideal gas, for which we have an equation of state: the ideal gas law. In other media, we need an equation of state in order to generate similar solutions. Luckily, such an EOS is available for real materials through the Hugoniot function and empirically determined values.

But modeling Alderaan as a shockwave may be pointless; the sheer amount of energy involved is so great that the mechanism becomes less important.

drachefly · Post by **drachefly** » 2006-04-17 12:42pm

The molecular binding energy of the materials of Alderaan is insignificant compared to the power of the forces being applied to it. For that reason, I think an ideal gas treatment would be fine, so long as you used the right starting densities.

The shock wave model could help indicate the efficiency. Low efficiency would pump up the energy requirements further, while high efficiency would not (though again it would not provide an upper bound).

Post by **Surlethe** » 2006-04-17 04:48pm

So, I need to study up on fluid dynamics, ideal gas approximations, shockwaves and the Hugoniot function?

Post by **Darth Wong** » 2006-04-17 05:28pm

The problem in this case is that you have a shockwave but you also have a ridiculous amount of radiative heating. What exactly are you trying to determine?

Post by **Surlethe** » 2006-04-17 05:35pm

The idea I had (and I'm not sure if this is original or not) is that the initial explosion is caused in part by Alderaan's shields dropping and heating the crust and mantle of the planet. If this is the case, I have a vague notion that inertial confinement as well as the rest of the superlaser may have compressed the planet's core, which then exploded a second later in the second blast.

The problem is I'm not sure what to look for in testing this, and I'm not sure how to model it, so at this point it stands as useless speculation on my part.

Post by **Darth Wong** » 2006-04-17 05:51pm

All shockwaves are characterized by a pressure imbalance and confinement, ie- there will be greater pressure inside than outside. But that secondary burst may indicate that there was a small super-heated very high-pressure core portion which "broke through" the slower-moving outer layers after a natural propagation delay. This would imply a focused spike at the end of the superlaser burst.

Post by **Surlethe** » 2006-04-17 06:38pm

So, essentially, you're saying that the super-heated high-pressure core portion's explosion caught up to the outer layers of the explosion, which apparently caused a second explosion? How would that imply a focused spike in energy at the end of the superlaser burst?

Xess · Post by **Xess** » 2006-04-17 06:46pm

Surlethe wrote:So, essentially, you're saying that the super-heated high-pressure core portion's explosion caught up to the outer layers of the explosion, which apparently caused a second explosion? How would that imply a focused spike in energy at the end of the superlaser burst?

The way I understand it is that for the super-heated high-pressure core was created in the last moments of the explosion when the superlaser's energy spiked.