Effective Date: 15 June 98
Editor's Note: This propulsion section is still under graphics (equations) update.
The accurate calculation of inflight thrust on the generic high bypass engine is required to adequately determine the drag and performance characteristics of the airplane. Due to the high inlet mass flow rates, and the associated high thrust produced by the generic high bypass engine, the method of computing inflight thrust becomes more critical. The method of calculating thrust consists basically of measuring certain internal engine parameters and the core engine and fan (bypass) discharge temperatures and pressures from rakes and pick-ups installed by engine manufacture. From these measured data, mass flow rates and gross thrust parameters are calculated. Net thrust is computed by applying the appropriate coefficients to the ideal gross thrust and then subtracting the ram drag term.
The nozzle coefficients used in the calculation of thrust are derived from test results from model testing and full scale testing in the engine manufacture altitude chamber and test cells. The derivation of these coefficients is discussed in section on DERIVATIONs.