Browsing by Author "Sebastiampillai, Joshua"

Now showing 1 - 3 of 3
  • Thumbnail Image
    ItemOpen Access
    Modeling geared turbofan and open rotor engine performance for year-2050 long-range and short-range aircraft
    (ASME, 2019-10-04) Mastropierro, Francesco Saverio; Sebastiampillai, Joshua; Jacob, Florian; Rolt, Andrew Martin
    The paper provides design and performance data for two envisaged year-2050 engines: a geared high bypass turbofan for intercontinental missions and a contra-rotating pusher open rotor targeting short to medium range aircraft. It defines component performance and cycle parameters, general arrangements, sizes and weights. Reduced thrust requirements reflect expected improvements in engine and airframe technologies. Advanced simulation platforms have been developed to model the engines and details of individual components. The engines are optimised and compared with 'baseline' year-2000 turbofans and an anticipated year-2025 open rotor to quantify the relative fuel-burn benefits. A preliminary scaling with year-2050 'reference' engines, highlights trade-offs between reduced specific fuel consumption (SFC) and increased engine weight and diameter. These parameters are converted into mission fuel burn variations using linear and non-linear trade factors. The final turbofan has an optimised design-point bypass ratio of 16.8, and a maximum overall pressure ratio of 75.4, for a 31.5% TOC thrust reduction and a 46% mission fuel burn reduction per passenger kilometre compared to the respective 'baseline' engine-aircraft combination. The open rotor SFC is 9.5% less than the year-2025 open rotor and 39% less than the year-2000 turbofan, while the TOC thrust increases by 8% versus the 2025 open rotor, due to assumed increase in passenger capacity. Combined with airframe improvements, the final open rotor-powered aircraft has a 59% fuel-burn reduction per passenger kilometre relative to its baseline.
  • Thumbnail Image
    ItemOpen Access
    Scale effects on conventional and intercooled turbofan engine performance
    (Cambridge University Press, 2017-06-08) Rolt, Andrew Martin; Sethi, Vishal; Jacob, Florian; Sebastiampillai, Joshua; Xisto, Carlos M.; Grönstedt, Tomas; Raffaelli, Lorenzo
    New commercial aero engines for 2050 are expected to have lower specific thrusts for reduced noise and improved propulsive efficiency, but meeting the ACARE Flightpath 2050 fuel-burn and emissions targets will also need radical design changes to improve core thermal efficiency. Intercooling, recuperation, inter-turbine combustion and added topping and bottoming cycles all have the potential to improve thermal efficiency. However, these new technologies tend to increase core specific power and reduce core mass flow, giving smaller and less efficient core components. Turbine cooling also gets more difficult as engine cores get smaller. The core-size-dependent performance penalties will become increasingly significant with the development of more aerodynamically efficient and lighter-weight aircraft having lower thrust requirements. In this study the effects of engine thrust and core size on performance are investigated for conventional and intercooled aeroengine cycles. Large intercooled engines could have 3%–4% SFC improvement relative to conventional cycle engines, while smaller engines may only realize half of this benefit. The study provides a foundation for investigations of more complex cycles in the EU Horizon 2020 ULTIMATE programme. This paper will be presented at the ISABE 2017 Conference, 5-8 September 2017, Manchester, UK.
  • Thumbnail Image
    ItemOpen Access
    Thermodynamic analysis of nutating disc engine topping cycles for aero-engine applications
    (Elsevier, 2019-05-31) Sebastiampillai, Joshua; Rolt, Andrew Martin; Jacob, Florian; Nalianda, Devaiah; Sethi, Vishal
    Within the next thirty years the evolutionary approach to aero engine development will struggle to keep abreast with increasingly stringent environmental targets. Therefore radical approaches to aero-engine development in terms of energy savings need to be considered. One particular concept involves the inclusion of a pressure-rise combustion system, within the architecture of an aero-engine, to provide additional shaft power. The nutating disc engine concept is a strong contender due to its power density. The feasibility of the nutating disc engine has been previously investigated for unmanned vehicle applications. However, this paper investigates the performance benefits of incorporating a nutating disc core in a larger geared open rotor engine for a potential entry in to service in 2050. In addition, a methodology is presented to estimate the size and weight of the nutating disc core. This methodology is pivotal in determining the overall performance of the novel aero-engine cycle. The outcome of this study predicts a potential 9.4% fuel burn benefit, over a state of the art geared open rotor in the year 2050. In addition, the sensitivity of the nutating disc design variables highlights the possible fuel burn benefits compared against a comparable year-2000 aircraft mission.