Thermal efficiency
The ratio of the amount of useful work produced by a heat engine, to the amount of work that could be done by all of the heat energy available in the fuel burned.
Aviation Maintenance Technician Handbook — Powerplant, p. G-27
The ratio of the amount of useful work produced by a heat engine, to the amount of work that could be done by all of the heat energy available in the fuel burned.
Aviation Maintenance Technician Handbook — Powerplant, p. G-27