Lower Mw alkanes are better because they produce light combustion gasses. The longer the carbon chain the lower the H/C ratio so the higher the proportion of high MW CO2.

@rcman

It got clogged up with methane clathrates that made it float to the surface.

Essentially, every choice you make is going to be a compromise; the greater the C:B ratio the greater the power, but also the greater the noise + impracticality and you face the law of diminishing returns - you're probably going to want it between 1:1 and 2:1 obviously depending on pressure. Just do...

1) -Universal fueling calculator (including several fuel/oxidizer and buffer
gas combinations)

-Ballistic efficiency calculator (based on initial conditions and
GGDT/HGDT output)

2) c) Construction

3) c) When necessary

4) b) Depends on the builds

5) 4

6) 9

7) 8

8) c) Moderately

On Wikipedia -I know, not the most reliable source - it claims that: 'In non-ideal gases, such as a van der Waals gas, the proportionality is not exact, and there is a slight dependence of sound velocity on the gas pressure.' Given that air is mostly composed of diatomic molecules (N2, O2), which te...

I was thinking of making a bursk-disk steam cannon; the design I'm contemplating is to have a sealed chamber of water, which would be heated until it burst the disk and forced the projectile out of the barrel. For the heating I was considering passing an electric current through the water using two ...

While the term 'HHO' is pretty dodgy (often associated with free energy etc.), this seems to me like a legitimate project employing the electrolysis of water to produce hydrogen. While it is certainly not cost competitive with propane this may be made up for by the increased refuelling intervals (wa...