Thermobaric weapons in dense atmospheres

Question

Would thermobaric weapons be more or less effective in a denser atmosphere of another planet?

On one hand the shockwaves would be harder because of the more tightly compressed air. On the other hand I suspect that the shockwaves would have less range because it would require more energy to push the air out of the way. So you might end up with a some lethal but more focused weapon? Am I correct in my assumptions?

Spinning this out to a more general question what would be a more effective weapon in such environments, explosive or fragmentation focused weapons?

Answer 1

Not an expert in shock waves here, but let's go exploring the domain.

• First end: vacuum (or density 0). No shock wave, as obviously there is nothing to propagate the pressure wave.
• Second end: solid (or liquid). Max effectiveness of the pressure wave, as the difference of impedance makes it easier to transfer energy from the shock wave to the target (that's why when someone gets an echo scan they apply a layer of gel between the scanning head and the body)

I would therefore say that the more dense the atmosphere is, the more effective the shock wave will be. You will be moving from the first end more close to the second end.

The dominant effect in the attenuation will still be the square law, consequence of the total shock wave area, while the density over the distance of propagation will only play linear.

Answer 2

Most known thermobaric devices are forms of "Fuel-Air Explosives" (FAE), so the true issue is to release the aerosolized fuel in such a manner that it mixes in a proper sociometric ratio with the oxygen available in the atmosphere.

In some respects, a denser atmosphere would increase the energy of a thermobaric or FAE, much like using a supercharger or turbocharger increases the power of an engine by increasing the amount of oxygen available in a given volume of the cylinder. The resulting explosion would have the shockwave transmitted more effectively due to the increased density of the atmosphere, but the thermal pulse of a thermobaric device might actually be absorbed more quickly, since the dense medium will absorb the heat energy.