Synthesis of Aero-Propulsive Interaction Studies Applied to Conceptual Hybrid-Electric Aircraft Design

This paper presents a synthesis of aero-propulsive interaction studies performed at Delft University of Technology, applied to conceptual aircraft designs with distributed hybrid-electric propulsion (DHEP). The studied aero-propulsive interactions include tip-mounted propulsion, wing leading-edge distributed propulsion and boundary-layer ingestion, combined with different primary propulsion-system arrangements. This paper starts with a description of the applied design framework and an overview of the aero-propulsive interactions. Subsequently, the different aircraft configurations are sized for a set of top-level requirements covering the range between regional turboprop to typical narrow-body turbofan aircraft. Results indicate that lower shaft power ratios show better performance, with the unoptimized DHEP concepts showing values of maximum take-off mass (MTOM) and payload-range energy efficiency (PREE) comparable to their reference aircraft. It was shown that beyond 20% shaft power ratio, the PREE decreases and MTOM increases much more than between 10% and 20%, indicating a possible local optimum between these values since even lower values did not yield any significant improvements. The benefits of tip-mounted propulsion are found to be constrained by the propeller blade tip Mach number in this particular analysis for the selected reference blade loading distribution. At the high range case for Mach 0.5, it can be seen that the distributed propulsion systems show the largest improvement.Flight Performance and Propulsio

Semi-Analytical Composite Oval Fuselage Weight Estimation

Flight Performance and Propulsio

Conceptual Assessment of Hybrid Electric Aircraft with Distributed Propulsion and Boosted Turbofans

This paper presents the results of a study into the effect of distributed hybrid-electric propulsion on aircraft performance and characteristics. To size these aircraft, a new preliminary sizing method for hybrid-electric aircraft with distributed propulsion, including aero-propulsive interaction, is combined with a modified Class-II weight estimation method where energy consumption is estimated through a mission analysis method. Comparison of the predictions from these new methods to the predictions from a traditional sizing method has shown to be within 5% agreement for a single-aisle aircraft powered by conventional turbofans in terms of wing loading, energy consumption and maximum take-off weight. A boosted turbofan aircraft as well as two aircraft with different distributed, hybrid-electric propulsion systems have been assessed for a 150-pax aircraft designed for a harmonic range of 800nmi. Each of these aircraft designs showed significant increases in propulsion system mass (up to 700%). The distributedpropulsion aircraft showed increases in energy consumption of 34% and 51%, respectively, over the conventional turbofan aircraft. However, the boosted-turbofan aircraft showed a 10% decrease in energy consumption and a 3% reduction in maximum take-off weight. Future studies have to be performed exploring the design space, including all powertrain components, thermal management components, mission parameters and propulsion system layout.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.Flight Performance and Propulsio

Comparação entre duas teorias para a determinação da tensão interfacial pelo método de fibra quebrante Comparison between two theories for determination of interfacial tension with the breaking thread method

A tensão interfacial entre polímeros fundidos é um fator chave para a predição da morfologia de blendas poliméricas. Neste trabalho, as teorias de Tomotika e Tjahjadi et al. para medir tensão interfacial entre polímeros fundidos usando o método de fibra quebrante são avaliadas e comparadas. Em particular, foram testadas ambas as teorias para o par de polímeros PP/PS à temperatura de 200 &deg;C. O valor médio de tensão interfacial calculado usando a teoria de Tomotika foi de 5,88 mN/m, e usando a teoria de Tjahjadi et al. foi de 5,66 mN/m.<br>Interfacial tension between molten polymers is a key factor that helps predicting the morphology of polymer blends. In this work, the theories of Tomotika and Tjahjadi et al. to measure interfacial tension between molten polymers using the breaking thread method are evaluated and compared. In particular, both theories were tested for PP/PS polymer pair at temperature of 200 &deg;C. The average values of interfacial tension calculated using Tomotika&acute;s theory and Tjahjadi et al.&acute;s theory are 5.88 mN/m and 5.66 mN/m, respectively

Handling Qualities Optimization in Aircraft Conceptual Design

Flight Performance and Propulsio