Sensitivity of Boundary Layer Ingestion Effects to Tube and Wing Airframe Design Features

Conceptual design of boundary layer ingesting (BLI) aircraft requires a methodology that captures the aero-propulsive interactions in a parametric fashion. This entails modeling the impacts of BLI as a function of the airframe and propulsor design. Previous work has analyzed the sensitivity of these BLI effects to the propulsor size and throttle. This paper assesses the sensitivity of the BLI effects to the airframe design through a series of experiments, using CFD. The scope of this analysis is restricted to tube and wing type BLI concepts. Results from these studies help identify the critical airframe design space that needs to be considered when generating a parametric model of the BLI effects. Guidelines regarding the level of detail required for the airframe geometry model are discussed

Radiolytic Yield of UIV Oxidation into UVI: A New Mechanism for UV Reactivity in Acidic Solution

International audienceThe yields of the radiolytic oxidation of UIV and of the UVI formation, measured by spectrophotometry, are found to be the same (G(−UIV)N2O = G(UVI)N2O = 8.4 × 10−7 mol J−1) and almost double the H2 formation yield (G(H2) = 4.4 × 10−7 mol J−1) in the 60Co γ radiolysis of N2O-aqueous solutions in the presence of 2 mol L−1 Cl− at pH = 0 (HCl). According to the mechanism of UIV radiolytic oxidation, we show that under the conditions of our experiments the UV ions do not disproportionate, but undergo a stoichiometric oxidation into UVI by H+ with forming H2

Preliminary design of next generation Mach 1.6 supersonic business jets to investigate landing & take-off (LTO) noise and emissions - SENECA

With the approach of next generation supersonic transport entry into service, new research activities were initiated to support updates on ICAO regulations and certification processes for supersonic transport vehicles. Within this context, the EU Horizon 2020 SENECA project has been launched to investigate the levels of noise and gaseous emissions in the vicinity of airports as well as the global climate impact of next generation supersonic civil aircraft. This paper introduces some of the preliminary outcomes of this investigation. It presents the preliminary design and performance analysis of a Mach 1.6 business jet, following an integrated aircraft-engine design approach. The preliminary design was performed accounting for the limitations posed by future environmental restrictions on respective subsonic vehicles. The market space and mission route definition exercise assumed only "over-sea"supersonic operations, while for "over-land", only subsonic operations where allowed. Parametric studies on engine integrated design demonstrated modest core temperatures while cruising and the significant impact of engine installation on performance. At this first design iteration, assuming current state of the art technology, the Mach 1.6 business jet showed good potential to satisfy the predicted mission requirements while respecting the environmental constraints in terms of Landing & Take-Off (LTO) noise and emissions