Influence of the gas turbine engine design parameters on the energy consumption of the multirole aircraft missions

In the article the analysis of the influence of design parameters of the engine on the performed by the multirole aircraft mission was performed. The problem is complex as a result of performing a series of manoeuvres in various conditions of flight. A special feature of multi-role aircraft mission is a sudden (even pulse) weight change and exactly its reduction as a result of the discharge of cargo bomb, rocket or due to the consumption of ammunition during air combat manoeuvring. Reducing the airplane mass by the weight of the fuel consumed (continuously) and the used weapons radically differ the demands on the energy required to overcome gravity and drag forces. The article shows how the reduction of the aircraft mass influences on the change of the thrust load factor. It was built the mathematical model of the system engine-aircraft-air job (taking into account the flight conditions, elements of the mission - subsonic and supersonic flight, flight time, the heat-and-gasdynamic and mass model of the engine). The model enables for the simulation research of the complex flight missions and their evaluation on the basis of the constructed criteria. The model includes a parametric description of physical processes in the turbofan engine, thus provides a direct assessment of the impact of selection of engine parameters on the effectiveness of the mission. The results of calculations according to classical criteria (e.g. kilometre fuel consumption, specific fuel consumption) were presented. The paper presents new criteria, which enable to analyze the energy consumption of the complex mission of the aircraft (e.g. energy consumption: the unit range, the degree of utilization of energy resources and the carried out the mission engine). Criteria were built in by combining the parameters necessary for the flight with disposable ones. On the basis of these parameters there was done an assessment of the "quantitative" adjustment of a power unit to various missions such as subsonic, supersonic and mixed (for different their proportion), for different levels and the plane range. The results were presented in a pictorial way on numerous charts.