Design and full 3D nose-to-tail computation of a turbofan+ scramjet Mach 8 civil aircraft

ithin the frame of the LAPCAT II project (Long-term Advanced Propulsion Concepts and Technologies, funded by the European Commission as part of the 7th Frame Program and involving 16 European research labs and industries), four concurrent system studies have been carried out to design a Mach 8 vehicle able to carry passengers on the Brussels-Sydney route. The required range is above 18000 km, and the defined number of passengers is 300, which correspond to a 60 tons / 1400 m3 payload. Inspired by the previous analysis led by Onera on PREPHA-based concepts, by the University of Rome on TBCC hypersonic performances and by Universite Libre de Bruxelles on precooled turbofan performances, a deeper analysis on a LH2 turbofan/ramjet/scramjet concept was performed, including a parametric sizing of the vehicle, a more detailed internal layout and especially a step-by-step numerical analysis of the aeropropulsive performances on the Mach 8 cruise point, using a nose-to-tail approach. The preliminary steps of the design process have been described in a previous paper. This new paper will focus on the progress made to enforce the consistency of the vehicle, especially regarding its 2-flowpaths propulsion system. Conceptual design of the low supersonic intake feeding the turbofans will be presented, as well as a final evaluation of its performance on the Mach 8 cruise point using a single-domain nose-to-tail computation where the combustion chamber is precisely modelled, including injection and bleeding systems. A new layout will then be presented, taking into account several options for the hydrogen tanks arrangement. 1 Research engineer, Long-term Design and System Department, Sebastien.Defoort@onera.fr. 2 Research engineer, Fundamental and Applied Energetics Department, Marc.Ferrier@onera.fr. 3 Head of advanced aeropropulsion systems, Long-term Design and System Department, Laurent.Serre@onera.fr. 4 Engineering student cyril.daghrir@ulb.ac.be 5 Professor – patrick.hendrick@ulb.ac.be W