FEATURES OF ASSESSING FUEL EFFICIENCY MODIFICATIONS OF MULTI-MOTION AIRCRAFT POWER INSTALLATIONS

Abstract

When creating modifications of transport category airplanes, fuel efficiency appears in the structure of their parameters.

This indicator is very important, since operating costs largely depend on the amount of fuel consumed per unit of work.

The problem of evaluating the fuel efficiency of modifications of transport aircraft with multi-engine power plants is considered. It is noted that multi-engine power plants, used mainly on medium and heavy aircraft, contribute to solving a number of problematic issues:

– expanding the ability to operate in hot climates and highlands;

– improving operational safety in the event of failure of one or two engines in case of deterioration of take-off/landing conditions, runway conditions, icing conditions and other emergency situations requiring increased thrust-to-weight ratio;

– expanding the network of airfields used by reducing the sites of continued or interrupted take-off;

– the absence of the need to use on the created modification more powerful engines, domestic or foreign, which do not have forced (emergency) operating modes.

– However, the use of forced-mode engines in such power plants leads to a deterioration in fuel efficiency of up to 20 percent.

For the preliminary design stage of modifications, a model is proposed for the formation of a fuel efficiency parameter while simultaneously replacing the main engines and changes in the wing geometry, which allows reducing fuel consumption for the flight, and thereby compensating for its losses when using emergency modes.

This approach was implemented in the process of development of the An-188 operational tactical military transport aircraft, in which the replacement of 4 theater with 4 turbojet engines was coordinated with the necessary changes in the wing geometry, which allowed the military-technical complex to ensure fuel consumption in horizontal flight mode with maximum payload 154 g/t∙km per unit of useful work, i.e., lower than that of competitors-analogues.