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cuspaceflight / bamboo

Cooling system modelling for liquid rocket engines.
GNU Affero General Public License v3.0
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Coolant pressure changes due to velocity changes #15

Closed dug20 closed 3 years ago

dug20 commented 3 years ago

Right now (I think) the pressure used in the pipes is the stagnation pressure, as opposed to the static pressure.

Might be worth doing a Bernoulli equation type thing with to get the static pressure, i.e. p0 = p + (1/2) rho V^2 (but I'm not sure what the best/correct way to implement this might be, or if it would make any significant changes).

HenryFree3 commented 3 years ago

Seems to be on the order of a few percent difference for velocities ~10 m/s and the current tank pressure, 20 bar. The way it's now implemented is by tracking the Bernoulli constant / stagnation pressure, using the pressure drop function to update it along the engine, and then derive the static pressure from this and the coolant velocity needed to ensure continuity.