Turbofan Engine Technology Evaluation System, User's Guide.

Abstract : The user guide includes a description of the general layout of the system, the general approach used in calculating gas properties throughout the engine simulation model, the recommended limitations and suggested constraints of the system, how the performance calculated by TRBOFN, the engine simulation program in this system, compares to SMOTE, an accepted standard turbofan engine simulation program, and discussion of the general conventions followed in developing the system. The Turbofan Engine Technology Evaluation System is intended to be a computer age back-of-the-envelope calculation tool for use in evaluating the relative payoffs of competing gas turbine engine technologies. The system consists of four programs: SETUP - an interactive graphics program used to select and input design cycle parameters for the engine and the flight conditions at which performance is to be calculated. TRBOFN - the turbofan engine performance simulation program; ENCOM - an interactive engine sizing and comparison program that also allows selection of performance parameters for graphs and comparison of up to five engines' performance powering an airplane through an eleven leg fighter/ground attack mission. The bottom line output in this comparison is the minimum fraction of take-off gross weight that must be fuel for the airplane to complete the mission using each engine under consideration; and GRAPH - an interactive graphics program for the creation of publication quality graphs of almost any calculated parameter versus any other.