A Preliminary Parametric Study for Geared, Intercooled and/or Recuperated Turbofan for Short Range Civil Aircrafts

Aviation plays a key role in economic prosperity and quality of lifestyle. However there is an increasing concern that current trends of consumption of natural resources cannot continue. It is imperative that major targeted investments are made into economical and reliable environment friendly propulsion and power solutions. A significant amount of this investment will be in the aerospace sector. A well utilised civil aircraft may burn more than 2000 times its weight in fuel during its life, so the examination of the propulsion system is essential from an environmental point of view. A preliminary parametric study for geared, intercooled and/or recuperated turbofan for short range commercial transport applications has been performed with regard to fuel consumption and emissions. A high by-pass ratio turbofan engine with performance characteristics and technology from the year 2000 was set up as a baseline. The results offer interesting qualitative comparisons showing that, for instance, a recuperated engine will yield a lower fuel burn for lower OPR values. An engine with a mid-compressor intercooler may give significant reduction of NO_x emissions whilst increasing the amount of CO₂. The intercooled and recuperated cycle offers higher thermal efficiencies (i.e. higher fuel consumption benefit) in comparison to other cycles at medium OPR values; therefore NO_x formation may be reduced as well as the engine core weight. Additionally, the inherent advantage of high BPR against low BPR turbofans in terms of SFC is evident (GTF). Clearly, therefore, an increase of BPR is an inevitable solution for the reduction of both fuel consumption and the level of noise produced, however this may involve NO_x and integration penalties, hence innovative cycles (e.g.: ICR) and state of the art combustor technology (e.g.: PERM and LDI combustors) must be considered. This is first on the series of work that would be carried out on the cycles being proposed in this paper. Further work on the issues of weight, noise, aircraft performance, other emissions, economics, etc, so-called a multidisciplinary objective assessment, would be published when completed. Also, at this time the design has been limited to take-off being the point of maximum aerodynamic performance. An extension to full mission is currently under investigation.