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reilleya / openMotor

An open-source internal ballistics simulator for rocket motor experimenters
GNU General Public License v3.0
401 stars 78 forks source link

Improved nozzle calculations #47

Closed reilleya closed 5 years ago

reilleya commented 5 years ago

Change how thrust is calculated. Calculations should take into account details like convergent/divergent section angles and throat length to reduce dependence on the "efficiency" that thrust is currently scaled by.

reilleya commented 5 years ago

http://www.rasaero.com/TECH_SUMMARY.htm shows how to relate thrust coefficient to nozzle geometry.

tuxxi commented 5 years ago

Check out my old code here for some other ideas. including some other departures from idea performance such as skin friction: https://github.com/tuxxi/OpenBurn/blob/master/openburn/core/internalballistics.py#L165

BurnSim's "efficiency" is called "two-phase flow efficiency" in the literature afaict.

reilleya commented 5 years ago

Thanks, that is exactly what I was looking for!