Performance and control optimisations using the adaptive torsion wing

2012 ◽  
Vol 116 (1184) ◽  
pp. 1061-1077 ◽  
Author(s):  
R. M. Ajaj ◽  
M. I. Friswell ◽  
W. G. Dettmer ◽  
G. Allegri ◽  
A. T. Isikveren
Keyword(s):  
Structural Model ◽  
Torsional Stiffness ◽  
Load Path ◽  
Aerodynamic Efficiency ◽  
Roll Control ◽  
Novel Concept ◽  
And Control ◽  
Multidisciplinary Design Optimisation ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Abstract This paper presents the Adaptive Torsion Wing (ATW) concept and performs two multidisciplinary design optimisation (MDO) studies by employing this novel concept across the wing of a representative UAV. The ATW concept varies the torsional stiffness of a two-spar wingbox by changing the enclosed area through the relative chordwise positions of the front and rear spar webs. The first study investigates the use of the ATW concept to improve the aerodynamic efficiency (lift-to-drag ratio) of the UAV. In contrast, the second study investigates the use of the concept to replace conventional ailerons and provide roll control. In both studies, the semi-span of the wing is split into five equal partitions and the concept is employed in each of them. The partitions are connected through thick ribs that allow the spar webs of each partition to translate independently of the webs of adjacent partitions and maintain a continuous load path across the wing span. An MDO suite consisting of a Genetic Algorithm (GA) optimiser coupled with a high-end low-fidelity aero-structural model was developed and employed in this paper.

Aerodynamic study of single corrugated variable-camber morphing aerofoil concept

2021 ◽  
pp. 1-29
Author(s):  
K. Dhileep ◽  
D. Kumar ◽  
P.N. Gautham Vigneswar ◽  
P. Soni ◽  
S. Ghosh ◽  
...  
Keyword(s):  
Finite Volume ◽  
Interpolation Method ◽  
Beam Theory ◽  
Small Deformation ◽  
Aerodynamic Characteristics ◽  
Ansys Fluent ◽  
Aerodynamic Efficiency ◽  
Finite Element Software ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Abstract Camber morphing is an effective way to control the lift generated by any aerofoil and potentially improve the range (as measured by the lift-to-drag ratio) and endurance (as measured by $C_l^{3/2}/C_d$ ). This can be especially useful for fixed-wing Unmanned Aerial Vehicles (UAVs) undergoing different flying manoeuvres and flight phases. This work investigates the aerodynamic characteristics of the NACA0012 aerofoil morphed using a Single Corrugated Variable-Camber (SCVC) morphing approach. Structural analysis and morphed shapes are obtained based on small-deformation beam theory using chain calculations and validated using finite-element software. The aerofoil is then reconstructed from the camber line using a Radial Basis Function (RBF)-based interpolation method (J.H.S. Fincham and M.I. Friswell, “Aerodynamic optimisation of a camber morphing aerofoil,” Aerosp. Sci. Technol., 2015). The aerodynamic analysis is done by employing two different finite-volume solvers (OpenFOAM and ANSYS-Fluent) and a panel method code (XFoil). Results reveal that the aerodynamic coefficients predicted by the two finite-volume solvers using a fully turbulent flow assumption are similar but differ from those predicted by XFoil. The aerodynamic efficiency and endurance factor of morphed aerofoils indicate that morphing is beneficial at moderate to high lift requirements. Further, the optimal morphing angle increases with an increase in the required lift. Finally, it is observed for a fixed angle-of-attack that an optimum morphing angle exists for which the aerodynamic efficiency becomes maximum.

scholarly journals Conceptual Design, Flying, and Handling Qualities Assessment of a Blended Wing Body (BWB) Aircraft by Using an Engineering Flight Simulator

Aerospace ◽  
2020 ◽  
Vol 7 (5) ◽  
pp. 51 ◽  
Author(s):  
Clayton Humphreys-Jennings ◽  
Ilias Lappas ◽  
Dragos Mihai Sovar
Keyword(s):  
Static Stability ◽  
Flight Simulator ◽  
Handling Qualities ◽  
Stability And Control ◽  
Flying Qualities ◽  
Blended Wing Body ◽  
And Control ◽  
Drag Ratio ◽  
Lift To Drag Ratio ◽  
Mission Profile

The Blended Wing Body (BWB) configuration is considered to have the potential of providing significant advantages when compared to conventional aircraft designs. At the same time, numerous studies have reported that technical challenges exist in many areas of its design, including stability and control. This study aims to create a novel BWB design to test its flying and handling qualities using an engineering flight simulator and as such, to identify potential design solutions which will enhance its controllability and manoeuvrability characteristics. This aircraft is aimed toward the commercial sector with a range of 3000 nautical miles, carrying 200 passengers. The BWB design was flight tested at an engineering flight simulator to first determine its static stability through a standard commercial mission profile, and then to determine its dynamic stability characteristics through standard dynamic modes. Its flying qualities suggested its stability with a static margin of 8.652% of the mean aerodynamic chord (MAC) and consistent response from the pilot input. In addition, the aircraft achieved a maximum lift-to-drag ratio of 28.1; a maximum range of 4,581 nautical miles; zero-lift drag of 0.005; while meeting all the requirements of the dynamic modes.

scholarly journals Aerodynamic Optimization of an Over-the-Wing-Nacelle-Mount Configuration

2011 ◽  
Vol 2011 ◽  
pp. 1-13 ◽  
Author(s):  
Daisuke Sasaki ◽  
Kazuhiro Nakahashi
Keyword(s):  
Interference Effect ◽  
Jet Engines ◽  
Aerodynamic Design ◽  
Aerodynamic Optimization ◽  
High Lift ◽  
Aerodynamic Efficiency ◽  
Wing Geometry ◽  
Aerodynamic Interference ◽  
Drag Ratio ◽  
Lift To Drag Ratio

An over-the-wing-nacelle-mount airplane configuration is known to prevent the noise propagation from jet engines toward ground. However, the configuration is assumed to have low aerodynamic efficiency due to the aerodynamic interference effect between a wing and a nacelle. In this paper, aerodynamic design optimization is conducted to improve aerodynamic efficiency to be equivalent to conventional under-the-wing-nacelle-mount configuration. The nacelle and wing geometry are modified to achieve high lift-to-drag ratio, and the optimal geometry is compared with a conventional configuration. Pylon shape is also modified to reduce aerodynamic interference effect. The final wing-fuselage-nacelle model is compared with the DLR F6 model to discuss the potential of Over-the-Wing-Nacelle-Mount geometry for an environmental-friendly future aircraft.

scholarly journals Vibration and Performance Analyses Using Individual Blade Pitch Controls for Lift-Offset Rotors

2019 ◽  
Vol 2019 ◽  
pp. 1-13 ◽  
Author(s):  
Jae-Sang Park ◽  
Do-Hyung Kim ◽  
Sanghyun Chae ◽  
Ye-Lin Lee ◽  
Jeong-In Go
Keyword(s):  
Phase Angle ◽  
High Speed ◽  
Actuation Frequency ◽  
Control Phase ◽  
Coaxial Rotor ◽  
Compound Helicopter ◽  
And Performance ◽  
And Control ◽  
Drag Ratio ◽  
Lift To Drag Ratio

This work attempts to reduce the hub vibratory loads of a lift-offset rotor using IBC (individual blade pitch control) in high-speed forward flight. As a lift-offset rotor for the present study, the rigid coaxial rotor of a XH-59A compound helicopter is considered and CAMRAD II is used to predict the hub vibration and rotor performance. Using the IBC with a single harmonic input at 200 knots, the vibration index of the XH-59A rotor is minimized by about 62% when the 3/rev actuation frequency is applied with the IBC amplitude of 1° and control phase angle of 270° (3P/1°/270°); however, the rotor effective lift-to-drag ratio decreases by 3.43%. When the 2/rev actuation frequency with the amplitude of 2° and control phase angle of 270° (2P/2°/270°) and the 3/rev actuation frequency using the magnitude of 1° and control phase angle of 210° (3P/1°/210°) are used in combination for the IBC with multiple harmonic inputs, the vibration index is reduced by about 62%, while the rotor effective lift-to-drag ratio increases by 0.37% at a flight speed of 200 knots. This study shows that the hub vibration of the lift-offset rotor in high-speed flight can be reduced significantly but the rotor performance increases slightly, using the IBC with multiple harmonic inputs.

scholarly journals A New Concept for Atmospheric Reentry Optimal Guidance: An Inverse Problem Inspired Approach

2013 ◽  
Vol 2013 ◽  
pp. 1-13 ◽  
Author(s):  
Davood Abbasi ◽  
Mahdi Mortazavi
Keyword(s):  
Inverse Problem ◽  
Analytical Solution ◽  
Atmospheric Reentry ◽  
Guidance And Control ◽  
Optimal Guidance ◽  
Future Space ◽  
Path Constraints ◽  
And Control ◽  
Drag Ratio ◽  
Lift To Drag Ratio

This paper presents a new concept for atmospheric reentry online optimal guidance and control using a method called MARE G&C that exploits the different time scale featured by reentry dynamics. The new technique reaches a quasi-analytical solution and simplified computations, even considering both lift-to-drag ratio and aerodynamic roll as control variables; in addition, the paper offers a solution for the challenging path constraints issue, getting inspiration from the inverse problem methodology. The final resulting algorithm seems suitable for onboard predictive guidance, a new need for future space missions.

On the effectiveness of active aeroelastic structures for morphing aircraft

2013 ◽  
Vol 117 (1197) ◽  
pp. 1167-1176 ◽  
Author(s):  
R. M. Ajaj ◽  
M. I. Friswell ◽  
E. I. Saavedra Flores
Keyword(s):  
Torsional Stiffness ◽  
Multidisciplinary Design ◽  
Flight Performance ◽  
Design Optimisation ◽  
Morphing Aircraft ◽  
Control Authority ◽  
And Control ◽  
Long Endurance ◽  
Multidisciplinary Design Optimisation ◽  
Shear Centre

AbstractThis note assesses the benefits of active aeroelastic structures (AAS) in enhancing flight performance and control authority. A representative AAS concept, whose torsional stiffness and shear centre position can be altered depending on the instantaneous flight condition, is employed in the wing of a medium altitude long endurance (MALE) UAV. A multidisciplinary design optimisation (MDO) suite is used in this study. It turns out that AAS can be very effective when used for enhancing control authority of the vehicle but have limited benefits in terms of flight performance (lift to drag).

scholarly journals A New Aerodynamic Optimization Method with the Consideration of Dynamic Stability

2021 ◽  
Vol 2021 ◽  
pp. 1-9
Author(s):  
Mi Baigang ◽  
Wang Xiangyu
Keyword(s):  
Dynamic Stability ◽  
Optimization Design ◽  
Optimization Method ◽  
Aerodynamic Optimization ◽  
Conventional Optimization ◽  
And Control ◽  
Drag Ratio ◽  
Lift To Drag Ratio ◽  
Oscillation Method ◽  
Small Amplitude Oscillation

Dynamic stability is significantly important for flying quality evaluation and control system design of the advanced aircraft, and it should be considered in the initial aerodynamic design process. However, most of the conventional aerodynamic optimizations only focus on static performances and the dynamic motion has never been included. In this study, a new optimization method considering both dynamic stability and general lift-to-drag ratio performance has been developed. First, the longitudinal combined dynamic derivative based on the small amplitude oscillation method is calculated. Then, combined with the PSO (particle swarm optimization) algorithm, a dynamic stability derivative that must not be decreased is added to the constraints of optimization and the lift-drag ratio is chosen as the optimization objective. Finally, a new aerodynamic optimization method can be built. We take NACA0012 as an example to validate this method. The results show that the dynamic derivative calculation method is effective and conventional optimization design can significantly improve the lift-drag ratio. However, the dynamic stability is enormously changed at the same time. By contrast, the new optimization method can improve the lift-drag performance while maintaining the dynamic stability.

scholarly journals Experimental Investigation of a Wing-in-Ground Effect Craft

2014 ◽  
Vol 2014 ◽  
pp. 1-7 ◽  
Author(s):  
M. Mobassher Tofa ◽  
Adi Maimun ◽  
Yasser M. Ahmed ◽  
Saeed Jamei ◽  
Agoes Priyanto ◽  
...  
Keyword(s):  
Research Work ◽  
Ground Effect ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Efficiency ◽  
Ground Clearance ◽  
Drag Forces ◽  
Lift And Drag ◽  
Drag Ratio ◽  
Lift To Drag Ratio ◽  
Wing In Ground Effect

The aerodynamic characteristics of the wing-in-ground effect (WIG) craft model that has a noble configuration of a compound wing was experimentally investigated and Universiti Teknologi Malaysia (UTM) wind tunnel with and without endplates. Lift and drag forces, pitching moment coefficients, and the centre of pressure were measured with respect to the ground clearance and the wing angle of attack. The ground effect and the existence of the endplates increase the wing lift-to-drag ratio at low ground clearance. The results of this research work show new proposed design of the WIG craft with compound wing and endplates, which can clearly increase the aerodynamic efficiency without compromising the longitudinal stability. The use of WIG craft is representing an ambitious technology that will help in reducing time, effort, and money of the conventional marine transportation in the future.

Numerical investigation of circulation control applied to flapless aircraft

2020 ◽  
Vol 92 (6) ◽  
pp. 879-893
Author(s):  
Zhi-Jie Fu ◽  
Yu-Wei Chu ◽  
Yi-Sheng Cai ◽  
He-Yong Xu ◽  
Yue Xu
Keyword(s):  
Energy Expenditure ◽  
Circulation Control ◽  
Aerodynamic Efficiency ◽  
Content Type ◽  
Momentum Coefficient ◽  
Equivalent Control ◽  
Control Authority ◽  
Flap Deflection ◽  
Drag Ratio ◽  
Lift To Drag Ratio

Purpose The purpose of this paper is to investigate the equivalent control authority of the conventional and circulation control (CC) wing of the aircraft and assess the energy expenditure and aerodynamic efficiency of the CC wing. Design/methodology/approach Four target cases with different flap deflection angles θ are set in advance for the conventional wing, and then a series of cases with different jet momentum coefficients Cμ are set for the CC wing. The lift, drag and momentum coefficient curves of the CC wing are compared to those of the four conventional wing cases. The curves with the best agreement are selected to establish the corresponding relation between θ and Cμ. The energy expenditure of the CC system is analyzed. The concept of equivalent lift-to-drag ratio for the CC wing is introduced to compare the aerodynamic efficiency with the conventional wing Findings The control authority of the conventional wing at θ = 0º, 10º, 20º, 30º are equivalent to the control authority of the CC wing with Cµ = 0.0, 0.005, 0.009 and 0.012. The CC system is more efficient at small Cµ than large Cµ. Practical implications This study could contribute to the application of the CC system on flapless aircrafts. Originality/value The corresponding relation between θ and Cµ is established by matching the equivalent control authority between the conventional wing and CC wing.

scholarly journals Computational Investigation of a Novel Box-Wing Aircraft Concept

2022 ◽  
Vol 12 (2) ◽  
pp. 752
Author(s):  
Mehedi Hasan ◽  
Stephane Redonnet ◽  
Andras Hernadi
Keyword(s):  
Structural Characteristics ◽  
Aerodynamic Performance ◽  
Research Model ◽  
Computational Investigation ◽  
Promising Alternative ◽  
Computational Fluid Dynamics Cfd ◽  
Novel Concept ◽  
Drag Ratio ◽  
Swept Wings ◽  
Lift To Drag Ratio

With regard to the current needs for greener aviation, this study focuses on a novel concept of Box-Wing Aircraft (BWA). Labelled SmartLiner (BWA/SL), this conceptual aircraft comes as a triplane comprising backward and forward swept wings. The aerodynamic performance and structural characteristics of this BWA/SL aircraft are here explored through numerical simulation, using Computational Fluid Dynamics (CFD) and Fluid-Structure Interaction (FSI). The computational approach is first validated using NASA’s Common Research Model (CRM) aircraft, which is then taken as a reference solution against which to compare the aero-structural merits of the BWA/SL concept. Results show that, although its design is still preliminary and lacks optimization, the BWA/SL aircraft exhibits very decent aerodynamic performance, with higher lifting capacities and a reasonable lift-to-drag ratio. Moreover, thanks to the closed frame of its peculiar planform, it demonstrates superior structural characteristics, including under extreme loading scenarios. Based on this preliminary analysis and considering the room left for its further optimization, this conceptual aircraft thus appears as a potentially promising alternative for the development of more environmentally friendly airliners.

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