Simplified Aerodynamics Models to Predict the Effects of Upstream Propellers on Wing Lift

Patterson, Michael D.; Daskilewicz, Matthew J.; German, Brian

doi:10.2514/6.2015-1673

Cited by 21 publications

(17 citation statements)

References 3 publications

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“…This design also had a mild leading edge sweep to provide the high-lift propeller discs some axial separation. This first revision also had only eight high-lift propellers, due to concerns associated with reduction in the lift augmentation effect associated with the height of the blown slipstream [18]. Unfortunately, the larger diameter of the high-lift propellers introduced a large excess thrust in the approach configuration, which could make approach to landing at low speed quite difficult.…”

Section: A Design Revisionsmentioning

confidence: 96%

“…A future paper will detail the low-order integrated aerodynamic-propulsion modeling approach used for the "cruisesized" wing analysis, along with the subsequent validation of this approach to higher-order computational methods. A companion paper by Patterson et al [15] describes the design of the high-lift propeller system, which has been built up from previous work [6,7,16,17,18,19]. …”

Section: A Initial Sizingmentioning

confidence: 99%

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Design and Performance of the NASA SCEPTOR Distributed Electric Propulsion Flight Demonstrator

Borer

Patterson

Viken

et al. 2016

16th AIAA Aviation Technology, Integration, and Operations Conference

Self Cite

185

109

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Distributed Electric Propulsion (DEP) technology uses multiple propulsors driven by electric motors distributed about the airframe to yield beneficial aerodynamic-propulsioninteraction. The NASA SCEPTOR flight demonstration project will retrofit an existing internal combustion engine-powered light aircraft with two types of DEP: small "high-lift" propellers distributed along the leading edge of the wing which accelerate the flow over the wing at low speeds, and larger cruise propellers located at each wingtip for primary propulsive power. The updated high-lift system enables a 2.5x reduction in wing area as compared to the original aircraft, reducing drag at cruise and shifting the velocity for maximum lift-to-drag ratio to a higher speed, while maintaining low-speed performance. The wingtip-mounted cruise propellers interact with the wingtip vortex, enabling a further efficiency increase that can reduce propulsive power by 10%. A tradespace exploration approach is developed that enables rapid identification of salient trades, and subsequent creation of SCEPTOR demonstrator geometries. These candidates were scrutinized by subject matter experts to identify design preferences that were not modeled during configuration exploration. This exploration and design approach is used to create an aircraft that consumes an estimated 4.8x less energy at the selected cruise point when compared to the original aircraft. Nomenclature = coefficient of drag 0 = coefficient of drag at zero lift = coefficient of lift = maximum coefficient of lift ⁄ = ratio of drag to dynamic pressure = battery specific energy = energy use per unit distance, conventional configuration = energy use per unit distance, distributed electric propulsion configuration = aircraft gross weight ℎ = altitude above mean sea level = induced drag constant ⁄ = ratio of lift to drag ( ⁄ ) = maximum ratio of lift to drag = mass of battery pack = power consumption of aircraft at cruise = specific excess power (instantaneous rate of climb capability) = rate of descent = range parameter at cruise power, no reserves = efficiency multiplier = velocity at cruise 0 = stall speed in the landing configuration , ∞ = airspeed velocity

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Section: A Design Revisionsmentioning

confidence: 96%

Section: A Initial Sizingmentioning

confidence: 99%

Design and Performance of the NASA SCEPTOR Distributed Electric Propulsion Flight Demonstrator

Borer

Patterson

Viken

et al. 2016

16th AIAA Aviation Technology, Integration, and Operations Conference

Self Cite

185

109

View full text Add to dashboard Cite

show abstract

“…These are smaller electric motors driving small-diameter, fixed-pitch, foldable propellers that are designed to operate in the low-speed rangetakeoff, initial climb, approach, and landing. The primary purpose of these propellers is to augment the low-speed flowfield over the wing by enhancing dynamic pressure and changing the local angle of attack distribution [10,11,12]. This effectively scales the low-speed, high-lift capabilities of the aircraft, much like a large, complex flap system.…”

Section: Figure 1: Nasa's X-57 "Maxwell" Distributed Electric Propulsmentioning

confidence: 99%

“…Subsequently, a simple model of lift augmentation from high-lift propellers based on fundamental "first principles" was developed by Patterson and German [12], and was later updated by Patterson et al [26,27]. This model assumed the isolated propeller performance could be superimposed on the wing, and abstracted the propeller slipstream to a single, average axial velocity to determine lift augmentation.…”

Section: B High-lift Propeller Design and Analysismentioning

confidence: 99%

Comparison of Aero-Propulsive Performance Predictions for Distributed Propulsion Configurations

Borer

Derlaga

Deere

et al. 2017

55th AIAA Aerospace Sciences Meeting

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NASA's X-57 "Maxwell" flight demonstrator incorporates distributed electric propulsion technologies in a design that will achieve a significant reduction in energy used in cruise flight. A substantial portion of these energy savings come from beneficial aerodynamicpropulsion interaction. Previous research has shown the benefits of particular instantiations of distributed propulsion, such as the use of wingtip-mounted cruise propellers and leading edge high-lift propellers. However, these benefits have not been reduced to a generalized design or analysis approach suitable for large-scale design exploration. This paper discusses the rapid, "design-order" toolchains developed to investigate the large, complex tradespace of candidate geometries for the X-57. Due to the lack of an appropriate, rigorous set of validation data, the results of these tools were compared to three different computational flow solvers for selected wing and propulsion geometries. The comparisons were conducted using a common input geometry, but otherwise different input grids and, when appropriate, different flow assumptions to bound the comparisons. The results of these studies showed that the X-57 distributed propulsion wing should be able to meet the as-designed performance in cruise flight, while also meeting or exceeding targets for high-lift generation in low-speed flight.

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“…To move forward and to estimate the values of ∆C L and ∆C D i , it is proposed the method addressed by Patterson, Daskilewicz and German (2015). This method represents the propellers as actuator disks and the wing as a flat plate, incorporating a semi-empirical correction for finite slipstream height.…”

Section: Aero-propulsive Interaction Modelmentioning

confidence: 99%

Contributions to Conceptual Design of Electric and Hybrid-electric Aircraft

Silva¹

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O trabalho de pesquisa realizado busca estudar como a definição de um sistema propulsivo híbrido impacta no projeto conceitual de aeronaves elétricas e híbridas. Em virtude das metas de redução de poluentes, ruídos e outras questões ambientais que são definidas por organizações internacionais, este tema de pesquisa tem se tornado muito relevante atualmente, sendo foco de trabalhos recentes em todo o mundo. Neste contexto, foram apresentadas as principais arquiteturas que formam os sistemas propulsivos híbridos, destacando suas vantagens e limitações, e foram listados exemplos de protótipos de aeronaves que já realizaram o primeiro voo, além de projetos que ainda estão em desenvolvimento. Em seguida, foram retratados os conceitos relativos a sistemas de propulsão distribuída (DP) e como seus efeitos aero-propulsivos podem influenciar no projeto conceitual final. Um método para construção de diagrama de restrições foi descrito e uma aeronave do tipo thin haul foi escolhida para ser o exemplo de aplicação. Os resultados mostraram uma melhora aerodinâmica devido ao DP, o que resultou em um aumentou do espaço viável de projeto, permitindo asas e conjuntos propulsivo menores. Além disso, foi proposta uma abordagem de dimensionamento por energia de fase de missão típica para estimar os pesos dos componentes da aeronave. A análise paramétrica mostrou que a missão exigida e a tecnologia de baterias atual é crucial para dimensionar a aeronave. Não obstante, foram apresentados os principais efeitos da eletrificação no projeto de aeronaves, juntamente com os desafios atuais e necessidades tecnológicas esperadas.

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Simplified Aerodynamics Models to Predict the Effects of Upstream Propellers on Wing Lift

Cited by 21 publications

References 3 publications

Design and Performance of the NASA SCEPTOR Distributed Electric Propulsion Flight Demonstrator

Design and Performance of the NASA SCEPTOR Distributed Electric Propulsion Flight Demonstrator

Comparison of Aero-Propulsive Performance Predictions for Distributed Propulsion Configurations

Contributions to Conceptual Design of Electric and Hybrid-electric Aircraft

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