On Sunday, December 15, 2019 at 6:42:14 PM UTC-5, JF Mezei wrote:
On 2019-12-15 11:02, William Elliot wrote:
Kerosene fuel for rockets is deliberately burned oxygen poor so the
unburnt fuel will add mass to the rocket's exhaust to give it more
thrust.


It was explained to me here before. Fuel rich mixture passes some
unburnt fuel through the nozzle, and much ends up burning in the engine
bell.

As the fuel burns in engine bell, it puts pressure on the top of the
bell as it is accelerated downward, hence adding to the force pushing
rocket upwards.

There is a term that I forget. It has to due
with combustion chamber internal dynamics.

It is analogous to a gun's ammunition dynamics.
A casing's volume and shape has a large effect
on firing pressures.

The outcome is the fact that fuel energy release
will not equate to rocket thrust.