How a Jet Engine Works, From First Principles: A Cycle Model Anyone Can Rerun, Checked With Chemistry, and a Path to Testing It in Nigeria

A jet engine does four things: it draws in air, squeezes it, heats it by burning fuel, and lets it rush out faster than it came in. This proposal explains each step from basic physics and models the whole engine in short Python code. The model shows why squeezing the air harder saves fuel, why hotter turbines give more thrust, and why airliners use large fans. At cruise, adding a fan that moves ten times more air than the core cuts fuel use per unit of thrust by about half, from 34.0 to 17.2 grams per kilonewton-second. A chemistry check with Cantera agrees with the model's combustor temperature to within 3% for large engines. Sustainable aviation fuel releases almost the same carbon dioxide when burned as fossil kerosene, so its benefit must come from where the carbon came from. The proposal ends with a safe test-stand plan for Nigeria.