scholarly journals Optimization of a3D Aircraft Morphing Wing with highly controllable Aerodynamic Performance

2020 ◽  
Vol 8 (6) ◽  
pp. 4295-4300
Keyword(s):  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Morphing Wing ◽  
Sole Purpose ◽  
Surface Areas ◽  
Cfd Method ◽  
Lift And Drag ◽  
Control Surfaces ◽  
Compare And Contrast ◽  
Aerodynamic Losses

the sole purpose of this project is to compare the aerodynamic performance of the modernistic wing with morphing techniques to the conventional one (i.e. wing with ailerons and flaps). The morphing wing is capable of enhancing the mission profiles through its significant geometrical changes in the surface areas (upper and lower area of wing). The primary aspiration is to calculate the CL and CD (coefficient of lift and drag) of real aircraft with conventional control surfaces and to compare its result with morphing wing. The morphing techniques also enables various prevention of aerodynamic losses (drag, vortices, noise, etc) caused due to geometrical discontinuities of conventional wing with aileron and flap in operating conditions (take-off, cruise, loiter, landing).Catia modelling of proposed wing is analysed by CFD method and to compare and contrast the aerodynamic performance with the conventional (hinged) wing.

scholarly journals Aerodynamic Performance Analysis of a Building-Integrated Savonius Turbine

Energies ◽  
2020 ◽  
Vol 13 (10) ◽  
pp. 2636
Author(s):  
Zhaoyong Mao ◽  
Guangyong Yang ◽  
Tianqi Zhang ◽  
Wenlong Tian
Keyword(s):  
Performance Analysis ◽  
Wind Energy ◽  
Wind Turbine ◽  
Wind Turbines ◽  
New Technology ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
High Rise ◽  
Turbine Performance ◽  
Cfd Method

The building-integrated wind turbine is a new technology for the utilization of wind energy in cities. Previous studies mainly focused on the wind turbines mounted on the roofs of buildings. This paper discusses the performance of Savonius wind turbines which are mounted on the edges of a high-rise building. A transient CFD method is used to investigate the performance of the turbine and the interaction flows between the turbine and the building. The influence of three main parameters, including the turbine gap, wind angle, and adjacent turbines, are considered. The variations of the turbine torque and power under different operating conditions are evaluated and explained in depth. It is found that the edge-mounted Savonius turbine has a higher coefficient of power than that operating in uniform flows; the average Cp of the turbine under 360-degree wind angles is 92.5% higher than the turbine operating in uniform flows. It is also found that the flow around the building has a great impact on turbine performance, especially when the turbine is located downwind of the building.

A Comparative Study of a Morphing Wing

2017 ◽  
Author(s):  
Eun Jung Chae ◽  
Amin Moosavian ◽  
Alexander M. Pankonien ◽  
Daniel J. Inman
Keyword(s):  
Fluid Dynamic ◽  
Three Dimensional ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Superior Performance ◽  
Cfd Modeling ◽  
Navier Stokes ◽  
Morphing Wing ◽  
Trailing Edge ◽  
Analytical Approaches

Along with recent advancements in novel materials and manufacturing processes, the interest in morphing wings has increased in order to further improve the aerodynamic performance of flying bodies. The morphing wing can be tailored to deliver superior performance, compared to its non-morphing counterparts, for multiple operating conditions and in varying flows. In particular, the morphing wing is implemented for drag reduction and lift enhancement, and hence, the maneuverability, adaptability, and capability of the morphing wing can encompass an even wider spectrum by changing the wing shape. In this research, an existing morphing UAV wing design, Spanwise Morphing Trailing Edge (SMTE), actuated by bending Macro Fiber Composites (MFCs), is considered to generate the spanwise sinusoidal variations on the trailing edge of the morphing wing. A comparative aerodynamic study of the morphing wing by varying the spatial frequency (i.e., number of waves along the span) and the phase shift (i.e., wave shape along the span) at different angles of attack is conducted through analytical approaches and numerical Computational Fluid Dynamic (CFD) simulations, which are validated with previous experimental measurements. The analytical approach uses the three-dimensional (3D) Prandtl lifting line theory, and the CFD modeling in turbulence flow solves the 3D Reynolds-Averaged Navier-Stokes (RANS) equations with the k-ω Shear Stress Transport (SST) turbulence model. Note that the numerical simulations of a morphing wing focus on the pre-stall condition to estimate the aerodynamic performance. This work extends a prior study about a nominal flight condition testing a morphing wing at multiple flight conditions to evaluate multi-point 1 performance. The results show that there are governing aerodynamic efficiency zones of the lift-to-drag ratio, endurance, and aircraft range within a zone of angles of attack. Therefore, the morphing wing is shown to have a good aerodynamic performance as compared to the non-morphing wing.

Withdrawal: A Study on the Aerodynamic Performance of a Morphing Wing during Pitching Motion

2020 ◽  
Author(s):  
Manoj Prabakar Sargunaraj ◽  
Dibya Raj R. Adhikari ◽  
Carlos E. Soto ◽  
Samik Bhattacharya
Keyword(s):  
Aerodynamic Performance ◽  
Morphing Wing ◽  
Pitching Motion

Numerical study of geometric morphing wings of the 1303 UCAV

2021 ◽  
pp. 1-17
Author(s):  
B. Nugroho ◽  
J. Brett ◽  
B.T. Bleckly ◽  
R.C. Chin
Keyword(s):  
Flight Control ◽  
Numerical Study ◽  
Aerodynamic Characteristics ◽  
Morphing Wing ◽  
Rolling Moment ◽  
Wide Range ◽  
Morphing Wings ◽  
Wing Geometry ◽  
Lift And Drag ◽  
Wing Morphing

ABSTRACT Unmanned Combat Aerial Vehicles (UCAVs) are believed by many to be the future of aerial strike/reconnaissance capability. This belief led to the design of the UCAV 1303 by Boeing Phantom Works and the US Airforce Lab in the late 1990s. Because UCAV 1303 is expected to take on a wide range of mission roles that are risky for human pilots, it needs to be highly adaptable. Geometric morphing can provide such adaptability and allow the UCAV 1303 to optimise its physical feature mid-flight to increase the lift-to-drag ratio, manoeuvrability, cruise distance, flight control, etc. This capability is extremely beneficial since it will enable the UCAV to reconcile conflicting mission requirements (e.g. loiter and dash within the same mission). In this study, we conduct several modifications to the wing geometry of UCAV 1303 via Computational Fluid Dynamics (CFD) to analyse its aerodynamic characteristics produced by a range of different wing geometric morphs. Here we look into two specific geometric morphing wings: linear twists on one of the wings and linear twists at both wings (wash-in and washout). A baseline CFD of the UCAV 1303 without any wing morphing is validated against published wind tunnel data, before proceeding to simulate morphing wing configurations. The results show that geometric morphing wing influences the UCAV-1303 aerodynamic characteristics significantly, improving the coefficient of lift and drag, pitching moment and rolling moment.

Performance Characterization of a Twin Scroll Volute for Turbocharging Applications

2018 ◽  
Author(s):  
Carlo Cravero ◽  
Mario La Rocca ◽  
Andrea Ottonello
Keyword(s):  
Experimental Data ◽  
Scientific Literature ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
Automatic Design ◽  
Cfd Model ◽  
Radial Turbine ◽  
Wide Range ◽  
Partial Admission

The use of twin scroll volutes in radial turbine for turbocharging applications has several advantages over single passage volute related to the engine matching and to the overall compactness. Twin scroll volutes are of increasing interest in power unit development but the open scientific literature on their performance and modelling is still quite limited. In the present work the performance of a twin scroll volute for a turbocharger radial turbine are investigated in some detail in a wide range of operating conditions at both full and partial admission. A CFD model for the volute have been developed and preliminary validated against experimental data available for the radial turbine. Then the numerical model has been used to generate the database of solutions that have been investigated and used to extract the performance. Different parameters and indices are introduced to describe the volute aerodynamic performance in the wide range of operating conditions chosen. The above parameters can be used for volute development or matching with a given rotor or efficiently implemented in automatic design optimization strategies.

Aerodynamic Analysis of an Airfoil With Leading Edge Pitting Erosion

2017 ◽  
Vol 139 (6) ◽  
Author(s):  
Yan Wang ◽  
Ruifeng Hu ◽  
Xiaojing Zheng
Keyword(s):  
Wind Turbine ◽  
Indirect Effects ◽  
Leading Edge ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Distribution Area ◽  
Navier Stokes Equation ◽  
Turbine Performance ◽  
Wind Turbine Airfoil ◽  
Cfd Method

Leading edge erosion is a considerable threat to wind turbine performance and blade maintenance, and it is very imperative to accurately predict the influence of various degrees of erosion on wind turbine performance. In the present study, an attempt to investigate the effects of leading edge erosion on the aerodynamics of wind turbine airfoil is undertaken by using computational fluid dynamics (CFD) method. A new pitting erosion model is proposed and semicircle cavities were used to represent the erosion pits in the simulation. Two-dimensional incompressible Reynolds-averaged Navier–Stokes equation and shear stress transport (SST) k–ω turbulence model are adopted to compute the aerodynamics of a S809 airfoil with leading edge pitting erosions, where the influences of pits depth, densities, distribution area, and locations are considered. The results indicate that pitting erosion has remarkably undesirable influences on the aerodynamic performance of the airfoil, and the critical pits depth, density, and distribution area degrade the airfoil aerodynamic performance mostly were obtained. In addition, the dominant parameters are determined by the correlation coefficient path analysis method, results showed that all parameters have non-negligible effects on the aerodynamics of S809 airfoil, and the Reynolds number is of the most important, followed by pits density, pits depth, and pits distribution area. Meanwhile, the direct and indirect effects of these factors are analyzed, and it is found that the indirect effects are very small and the parameters can be considered to be independent with each other.

scholarly journals On the prospects of improving the numerical analysis of symmetric airfoils at low Reynolds numbers and high angles of attack by a LES approach: the case of NACA0021 profile

2020 ◽  
Vol 197 ◽  
pp. 08015
Author(s):  
Simone Giaccherini ◽  
Filippo Mariotti ◽  
Lorenzo Pinelli ◽  
Michele Marconcini ◽  
Alessandro Bianchini
Keyword(s):  
Turbine Blades ◽  
Separated Flow ◽  
Reynolds Numbers ◽  
Aerodynamic Performance ◽  
Operating Conditions ◽  
High Fidelity ◽  
Complex Flow ◽  
Energy Applications ◽  
Low Reynolds ◽  
High Angles Of Attack

The working conditions of airfoils along modern wind turbine blades are putting new focus on the importance of properly characterizing the aerodynamic performance of different airfoil families also at high angles of attack (AoAs) beyond stall and at Reynolds numbers much lower (from few thousands to one million) than those commonly analyzed before. Several test cases are showing that even higher-order computational methods (like RANS/URANS CFD) are unable to properly capture the complex flow physics taking place past the blades, when deep stall occurs or when the AoA changes so rapidly to provoke the onset of dynamic stall. To fill this gap, the use of high-fidelity methods, like the Large Eddy Simulation (LES) is proposed, even though it implies a massive increase of the calculation cost. In order to analyze the prospects of using LES in comparison to RANS for low Reynolds, high AoAs, this work presents an in-depth study of the NACA 0021 aerodynamics at the Reynolds number of 80,000, by means of both traditional RANS approaches and high-fidelity (LES) simulations using the OpenFOAM suite. The selected airfoil has been showing in fact several issues in the correct characterization of its performance in similar conditions in many recent wind energy applications. The LES approach showed the ability to overcome the limitations of traditional RANS simulations, improving the accuracy of the results and reducing their dispersion thanks to the fact that the flow structures in the separated-flow regions are properly captured. Overall, this work underlines that accurate investigations of the aerodynamic performance of the NACA 0021 at low Reynolds require multiple sensitivity studies when RANS approaches are used, and suggests the use of LES simulations in order to increase the accuracy of estimations, especially when studying the stalledflow operating conditions of the airfoil.

scholarly journals Aerodynamic Performance of the NREL S826 Airfoil in Icing Conditions

2017 ◽  
Author(s):  
Julie Krøgenes ◽  
Lovisa Brandrud ◽  
Richard Hann ◽  
Jan Bartl ◽  
Tania Bracchi ◽  
...  
Keyword(s):  
Wind Farm ◽  
Aerodynamic Performance ◽  
Cold Climate ◽  
Navier Stokes ◽  
Computational Results ◽  
Energy Potential ◽  
Pressure Distributions ◽  
Wind Energy Potential ◽  
Experimental Values ◽  
Lift And Drag

Abstract. The demand for wind power is rapidly increasing, creating opportunities for wind farm installations in more challenging climates. Cold climate areas, where ice accretion can be an issue, are often sparsely populated and have high wind energy potential. Icing may lead to severely reduced aerodynamic performance and thereby reduced power output. To reach a greater understanding of how icing affects the aerodynamics of a wind turbine blade, three representative icing cases; rime ice, glaze ice and a mixed ice, were defined and investigated experimentally and computationally. Experiments at Re = 1.0 × 105–4.0 × 105 were conducted in the low-speed wind tunnel at NTNU on a two dimensional wing with applied 3D-printed ice shapes, determining lift, drag and surface pressure distributions. Computational results, obtained from the Reynolds Averaged Navier–Stokes fluid dynamics code FENSAP, complement the experiments. Measured and predicted data show a reduction in lift for all icing cases. Most severe is the mixed ice case, with a lift reduction of up to 30 % in the linear lift area, compared to a clean reference airfoil. Computational results show an under-prediction in maximum lift of 7–18 % compared to experimental values. Curvature and tendencies for both lift and drag show good agreement between simulations and experiment.

Influence of wing kinematics on aerodynamic performance in hovering insect flight

2007 ◽  
Vol 594 ◽  
pp. 341-368 ◽  
Author(s):  
FRANK M. BOS ◽  
D. LENTINK ◽  
B. W. VAN OUDHEUSDEN ◽  
H. BIJL
Keyword(s):  
Insect Flight ◽  
Fruit Fly ◽  
Aerodynamic Performance ◽  
Navier Stokes ◽  
Insect Wing ◽  
Wing Kinematics ◽  
Drag Forces ◽  
Kinematic Models ◽  
Characteristic Features ◽  
Lift And Drag

The influence of different wing kinematic models on the aerodynamic performance of a hovering insect is investigated by means of two-dimensional time-dependent Navier–Stokes simulations. For this, simplified models are compared with averaged representations of the hovering fruit fly wing kinematics. With increasing complexity, a harmonic model, a Robofly model and two more-realistic fruit fly models are considered, all dynamically scaled at Re = 110. To facilitate the comparison, the parameters of the models were selected such that their mean quasi-steady lift coefficients were matched. Details of the vortex dynamics, as well as the resulting lift and drag forces, were studied.The simulation results reveal that the fruit fly wing kinematics result in forces that differ significantly from those resulting from the simplified wing kinematic models. In addition, light is shed on the effect of different characteristic features of the insect wing motion. The angle of attack variation used by fruit flies increases aerodynamic performance, whereas the deviation is probably used for levelling the forces over the cycle.

Effects of Airfoil’s Polar Data in the Stall Region on the Estimation of Darrieus Wind Turbine Performance

2016 ◽  
Author(s):  
David Marten ◽  
Alessandro Bianchini ◽  
Georgios Pechlivanoglou ◽  
Francesco Balduzzi ◽  
Christian Navid Nayeri ◽  
...  
Keyword(s):  
Unsteady Aerodynamics ◽  
Vertical Axis ◽  
Design Guidelines ◽  
Operating Conditions ◽  
Performance Estimation ◽  
Simulation Methods ◽  
Computationally Efficient ◽  
Urban Context ◽  
Lift And Drag ◽  
Thrust And Torque

Interest in vertical-axis wind turbines (VAWTs) is experiencing a renaissance after most major research projects came to a standstill in the mid 90’s, in favour of conventional horizontal-axis turbines (HAWTs). Nowadays, the inherent advantages of the VAWT concept, especially in the Darrieus configuration, may outweigh their disadvantages in specific applications, like the urban context or floating platforms. To enable these concepts further, efficient, accurate, and robust aerodynamic prediction tools and design guidelines are needed for VAWTs, for which low-order simulation methods have not reached yet a maturity comparable to that of the Blade Element Momentum Theory for HAWTs’ applications. The two computationally efficient methods that are presently capable of capturing the unsteady aerodynamics of Darrieus turbines are the Double Multiple Streamtubes (DMS) Theory, based on momentum balances, and the Lifting Line Theory (LLT) coupled to a free vortex wake model. Both methods make use of tabulated lift and drag coefficients to compute the blade forces. Since the incidence angles range experienced by a VAWT blade is much wider than that of a HAWT blade, the accuracy of polars in describing the stall region and the transition towards the “thin plate like” behaviour has a large effect on simulation results. This paper will demonstrate the importance of stall and post-stall data handling in the performance estimation of Darrieus VAWTs. Using validated CFD simulations as a baseline, comparisons are provided for a blade in VAWT-like motion based on a DMS and a LLT code employing three sets of post-stall data obtained from a wind tunnel campaign, XFoil predictions extrapolated with the Viterna-Corrigan model and a combination of them. The polar extrapolation influence on quasi-steady operating conditions is shown and azimuthal variations of thrust and torque are compared for exemplary tip-speed ratios (TSRs). In addition, the major relevance of a proper dynamic stall model into both simulation methods is highlighted and discussed.

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