Showing papers in "Journal of Aircraft in 2021"
TL;DR: Two propeller interaction types were distinguished in this paper for electric vertical takeoff and landing concepts characterized by nontraditional vehicle layouts with distributed propellers.
Abstract: Many electric vertical takeoff and landing concepts are characterized by nontraditional vehicle layouts with distributed propellers. Two propeller interaction types were distinguished in this Paper, which investigates how propeller interaction in side-by-side and one-after-another configuration affects performance, in terms of thrust, power, in-plane forces, and out-of-plane moments, and how those performance effects depend on axial and lateral propeller spacing. A wind-tunnel experiment was performed with two propeller units, one instrumented with a force/torque sensor and the other introducing the aerodynamic interaction. Total pressure and planar particle-image velocimetry measurements were taken to investigate slipstream characteristics. A strong dependency of interaction effects on the geometric layout was found. For side-by-side interaction characteristic of vertical takeoff and transition, interaction effects varied from weak at small angle of attack to strong at larger angles. A drop in rear propeller thrust of up to 30% was found at constant advance ratio. Keeping thrust constant resulted in power penalties up to 13% for the two propellers combined. For one-after-another interaction, characteristic of cruise, a maximum reduction of thrust of up to 80% was observed. Thrust compensation led to power penalties up to 30% for the rear propeller alone. An extended blade element momentum model captured most interaction effects with sufficient accuracy.
23 citations
TL;DR: In recent years, multilayered hierarchical compositions of the well-known and widely used Gaussian process models called deep Gaussian processes are finding use in the approximation of black-box fu...
Abstract: In recent years, multilayered hierarchical compositions of the well-known and widely used Gaussian process models called deep Gaussian processes are finding use in the approximation of black-box fu...
21 citations
TL;DR: The recent growth of interest in hybrid-electric and fully electric aircraft has led to a renewed focus on the design and optimization of propeller aircraft, with a focus on propeller–wing interaction.
Abstract: The recent growth of interest in hybrid-electric and fully electric aircraft has led to a renewed focus on the design and optimization of propeller aircraft. Considering propeller–wing interaction ...
19 citations
TL;DR: In this article, a model of a cantilevered plate subjected to axial supersonic flow is presented, where the model is based on the model of highly deflected structures in aeroelastic settings.
Abstract: Research interest is growing for theoretical models of highly deflected structures in aeroelastic settings. Presented here is a model of a cantilevered plate subjected to axial supersonic flow to d...
19 citations
TL;DR: In this paper, a wide range of aerodynamic conditions, including large incidence angles relative to oncomin...Propellers used for electric vertical takeoff and landing (eVTOL) aircraft propulsion systems are described.
Abstract: Propellers used for electric vertical takeoff and landing (eVTOL) aircraft propulsion systems experience a wide range of aerodynamic conditions, including large incidence angles relative to oncomin...
17 citations
TL;DR: In this paper, the influence of flared-hinge folding wingtips on the aerodynamic derivatives and flight dynamics of a narrow-body transport aircraft was studied, in addition to fold angle, h...
Abstract: This paper studies the influence of flared-hinge folding wingtips on the aerodynamic derivatives and flight dynamics of a narrow-body transport aircraft. In addition, the influence of fold angle, h...
15 citations
TL;DR: In this paper, the lift of a finite wing using a sheet of semi-infinite vortices extending from a vortex filament placed along the locus of aerodynamic centers of the wing is predicted.
Abstract: Implementations of lifting-line theory predict the lift of a finite wing using a sheet of semi-infinite vortices extending from a vortex filament placed along the locus of aerodynamic centers of th...
14 citations
TL;DR: It appears that the distributed flow and force sensor arrays found in flying animals are instrumented arrays that exploit highly nonlinear dynamics to achieve efficient and robust flight control.
Abstract: Flying animals exploit highly nonlinear dynamics to achieve efficient and robust flight control. It appears that the distributed flow and force sensor arrays found in flying animals are instrumenta...
14 citations
TL;DR: The second generation of supersonic civil transport has to match ambitious targets in terms of efficiency to be economically and environmentally viable as mentioned in this paper, and computational fluid dynamics-based design op...
Abstract: The second generation of supersonic civil transport has to match ambitious targets in terms of efficiency to be economically and environmentally viable. Computational fluid dynamics-based design op...
14 citations
TL;DR: In this article, the authors look set to use longer wingspans to increase the aspect ratio and increase the overall aerodynamic efficiency of the airframe, which will reduce roll rates and reduce the overall energy consumption of the aircraft.
Abstract: Future aircraft designs look set to use longer wingspans to increase the aspect ratio and therefore overall aerodynamic efficiency of the airframe. Such larger wingspans also reduce roll rates and ...
14 citations
TL;DR: In this article, the authors present a theoretical investigation into the potential use of structural power composites in regional aircraft passenger cabins and the corresponding challenges to widespread use, in particular, in the case of small aircraft.
Abstract: This paper presents a theoretical investigation into the potential use of structural power composites in regional aircraft passenger cabins and the corresponding challenges to widespread use, inclu...
TL;DR: In this paper, the integrated propeller-wing system design space is investigated to gain insight into the influence of propeller diameter, location, and rotation direction on the performance of the system.
Abstract: In this Paper, the integrated propeller–wing system design space is investigated to gain insight into the influence of propeller diameter, location, and rotation direction To conduct this investig
TL;DR: In order to achieve improvements in aircraft efficiency and reduced environmental footprint, aircraft must incorporate novel concepts, architectures, and technologies, such as distributed electric propulsio-... as discussed by the authors.
Abstract: To achieve improvements in aircraft efficiency and reduced environmental footprint, aircraft must incorporate novel concepts, architectures, and technologies, such as distributed electric propulsio...
TL;DR: Air vehicle sizing requires the ability to estimate the propulsive power and energy requirements of a flight vehicle as well as its weight.
Abstract: Air vehicle sizing requires the ability to estimate the propulsive power and energy requirements of a flight vehicle as well as its weight. Existing tools and methods for aircraft sizing typically ...
TL;DR: In this article, three test cases were presented that reproduce experiments carried out at the NASA's Glenn Icing Research Tunnel facility and they investigated in-flight ice accretion under parametric uncertainty.
Abstract: In-flight ice accretion under parametric uncertainty is investigated. Three test cases are presented that reproduce experiments carried out at the NASA’s Glenn Icing Research Tunnel facility. A pre...
TL;DR: A key challenge in the design of hybrid-electric propulsion systems (HEPSs) for aircraft is the complexity involved in handling efficient sizing of the components as well as control synergy between them.
Abstract: A key challenge in the design of hybrid-electric propulsion systems (HEPSs) for aircraft is the complexity involved in handling efficient sizing of the components as well as control synergy between...
TL;DR: Active flow control has not found wide application in aircraft due to a combination of technical challenges, costs, and small impact on overall aircraft performance as mentioned in this paper. But future applications, like alleviation, could benefit from active flow control.
Abstract: Active flow control has not found wide application in aircraft due to a combination of technical challenges, costs, and small impact on overall aircraft performance. Future applications, like allev...
TL;DR: In this article, a high-fidelity coupled computational fluid dynamics and comprehensive analysis solver for helicopter flight on Mars is developed, with the objectives of accurate prediction of flight loads and fundame...
Abstract: A high-fidelity coupled computational fluid dynamics and comprehensive analysis solver is developed for helicopter flight on Mars. The objectives are accurate prediction of flight loads and fundame...
TL;DR: In this paper, the aerodynamic design and fuel burn performance of a Mach-0.78 strut-braced-wing regional jet are investigated through aerodynamic shape optimization based on the Reynolds-averaged Navier-Stokes eq...
Abstract: The aerodynamic design and fuel burn performance of a Mach-0.78 strut-braced-wing regional jet is investigated through aerodynamic shape optimization based on the Reynolds-averaged Navier–Stokes eq...
TL;DR: In this article, the unsteady flows produced over the stern of a Simple Frigate Shape 2 ship model are studied in a low-speed wind tunnel using time-resolved particle image velocimetry (TR-PIV).
Abstract: The unsteady flows produced over the stern of a Simple Frigate Shape 2 ship model are studied in a low-speed wind tunnel. Time-resolved particle image velocimetry (TR-PIV) measurements were perform...
TL;DR: A summary and statistical analysis of the near field computational fluid dynamics (CFD) submissions for the Third AIAA Sonic Boom Prediction Workshop is provided with a focus on the C608 Low Boom F... as mentioned in this paper.
Abstract: A summary and statistical analysis of the near-field computational fluid dynamics (CFD) submissions for the Third AIAA Sonic Boom Prediction Workshop is provided with a focus on the C608 Low Boom F...
TL;DR: In this paper, a lack of experimental and computational information in the public domain regard to the effects of Icing on 3D lifting surfaces has been identified. But, there is no experimental or computational information available.
Abstract: Icing on three-dimensional lifting surfaces has been shown to produce highly complex flowfields. However, there is a lack of experimental and computational information in the public domain regardin...
TL;DR: In this paper, the wake dynamics of coaxial rotors were studied using the high-wake-resolution method, which is a combination of the truncated vortex tube model and the high wake resolution method.
Abstract: In this Paper, the wake dynamics of coaxial rotors are studied using the high-wake-resolution method. The high-wake-resolution method is a novel combination of the truncated vortex tube model for i...
TL;DR: In this article, improved delayed detached eddy simulation (IDDES) is used to numerically investigate the performance of a 3D aircraft control surface using coflow jet (CFJ) active f...
Abstract: This paper conducts improved delayed detached eddy simulation (IDDES) to numerically investigate the performance of a three-dimensional (3D) aircraft control surface using coflow jet (CFJ) active f...
TL;DR: This paper’s approach, direct optimization of a computationally efficient multifidelity local search algorithm for aerodynamic design optimization is presented.
Abstract: In this paper, a computationally efficient multifidelity local search algorithm for aerodynamic design optimization is presented. In this paper’s approach, direct optimization of a computationally ...
TL;DR: This work states that accurate modeling of aircraft fuel consumption, emissions, and noise is crucial in evaluating new air transportation operational procedures and policies to abate negative environmental impacts.
Abstract: Accurate modeling of aircraft fuel consumption, emissions, and noise is crucial in evaluating new air transportation operational procedures and policies to abate negative environmental impacts. The...
TL;DR: In this article, the authors presented computational prediction of aerodynamic hysteresis loops in static conditions for a two-dimensional aerofoil that was used as a cross-section profile for a rectangular wing.
Abstract: The paper presents computational prediction of aerodynamic hysteresis loops in static conditions for a two-dimensional aerofoil that was used as a cross-section profile for a rectangular wing with ...
TL;DR: In this paper, the authors focus on balancing accurate and efficient estimation of aerothermodynamic loads of high-speed vehicles with multidisciplinary modeling and analysis of high speed vehicles.
Abstract: Balancing accurate and efficient estimation of aerothermodynamic loads is a significant challenge for multidisciplinary modeling and analysis of high-speed vehicles. This study focuses on this issu...