[ncmncm]

I wonder about screwing a solid slug of aluminum down through the top of the combustion chamber during the first few seconds of launch, to get more massive exhaust particles (Al2O3) when you need that most. The top of the slug would be something refractory to seal the hole when the top end hits the stop.

The energetics of burning aluminum are pretty favorable, enough so that there are solid rocket boosters that use it. 1500 C is hot enough to liquify aluminum pretty vigorously, but not boil it.

[melony]

Doable, but one mistake in modeling and the whole thing goes boom. I like the idea, it reminds me of detonation engines.

[ncmncm]

Yeah, but they always want to go boom. That's what makes it rocket science.

I was taken by the the idea of a lead screw as a fuel pump.