Turbofan engine performance optimization based on aircraft cruise thrust level

Abstract

The aim of this paper is to define a methodology to minimize the adjustment effort required to comply with aircraft design performance requirements, when commercial off-the-shelf turbofan engines are installed, which is a challenge to aircraft manufactures. In order to achieve an efficient operation, a reasonable proposal is to adapt the propulsive performance by turbofan engine optimization. This work is carried out according to the following steps: (i) creation of estimated performance curves for a gas turbine from limited data; (ii) analysis of the impacts on performance and propulsive integration, applying computer simulation of the most promising engine components configuration; and (iii) matching between the lowest specific fuel consumption and the net thrust required for the cruise flight phase of the aircraft. The technical feasibility and the possible predisposition of engine manufactures to perform the implementation were also considered as critical points in this procedure. As a final result, an evaluation that presents the most suitable turbofan engine component modifications proposal to comply with engine/aircraft performance integration to be applied in the conceptual design phase was obtained.

On the early stages of precipitation during direct ageing of Alloy 718

“…Average volume fraction and number density follow v ~ t, and d ~ t 3 laws, respectively. The increasingly anisotropic morphology from ~0.6 h DA shows the onset of γ'-and γ"-precipitate growth ( Figures 4,5,7,8). Describing γ'-and γ"-precipitates as ellipsoids in Figure 10, predominantly spherical particles (~0.8 oblateness and aspect ratio) evolve into disc-shaped particles (~0.5 oblateness and aspect ratio).…”

“…More economical air travel is essential in the future as world annual air-traffic approximately doubles every two decades, where the key driver is the desire to cover longer distances with reduced travel time [3]. Therefore, increasing the aircraft engine efficiency for higher operational temperatures and workloads requires materials with improved high-temperature durability [4,5]. However, the development of novel alloys and/or advanced new thermo-mechanical processing of existing alloys are presently challenged to reach service cycles of >100,000 h at current operational temperatures of ~650 °C under the high mechanical service stresses [6,7].…”