Nozzle and wing geometry effects on OTW aerodynamic characteristics

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.

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Study on Wing Geometry for the Influence of Flapping Wing Aerodynamic Characteristics

2019 International Conference on Intelligent Computing, Automation and Systems (ICICAS) ◽

10.1109/icicas48597.2019.00189 ◽

2019 ◽

Author(s):

Cui Wang ◽

Qiang Jing ◽

Jiangbo Sun ◽

Qingling Wu ◽

Zhenya Chu ◽

...

Keyword(s):

Aerodynamic Characteristics ◽

Flapping Wing ◽

Wing Geometry

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Assessment at full scale of nozzle/wing geometry effects on OTW aeroacoustic characteristics

The Journal of the Acoustical Society of America ◽

10.1121/1.2017103 ◽

1979 ◽

Vol 65 (S1) ◽

pp. S139-S140

Author(s):

D. Groesbeck ◽

U. von Glahn

Keyword(s):

Full Scale ◽

Wing Geometry ◽

Geometry Effects

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Investigation of a NACA0012 Finite Wing Aerodynamics at Low Reynold’s Numbers and 0º to 90º Angle of Attack

Journal of Aerospace Technology and Management ◽

10.5028/jatm.v11.1023 ◽

2019 ◽

Author(s):

Shahrooz Eftekhari ◽

Abdulkareem Shafiq Mahdi Al-Obaidi

Keyword(s):

Drag Force ◽

Lift Coefficient ◽

Angle Of Attack ◽

Poor Performance ◽

Aerodynamic Characteristics ◽

Airfoil Surface ◽

Wing Geometry ◽

Stall Angle ◽

Finite Wing ◽

Lift And Drag

The aerodynamic characteristics of a NACA0012 wing geometry at low Reynold’s numbers and angle of attack ranging from 0º to 90º are investigated using numerical simulations and the results are validated by wind tunnel experiments. Further experiments are conducted at low Reynold’s numbers of 1 × 105, 2 × 105 and 3 × 105. Findings of the study show a similar trend for the lift and drag coefficients at all the investigated Reynold’s numbers. The lift coefficient is linearly increased with angle of attack until it reaches its maximum value at 32º which is the stall angle. It is observed that further increment in angle of attack results in decrement of lift coefficient until it reaches its minimum value at 90º angle of attack. The drag force acting on the airfoil increases as the angle of attack is increased and increment in the drag force results in change of laminar flow to turbulent flow. As the turbulence gets higher the flow starts to separate from the airfoil surface due to eddies generated by turbulence. Hence, the lift force generated by the wing is reduced and drag force is increased simultaneously, which results in poor performance of the wing.

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Aerodynamic Design of a Tailless Aeroplan

Acta Polytechnica ◽

10.14311/268 ◽

2001 ◽

Vol 41 (4-5) ◽

Author(s):

J. Friedl

Keyword(s):

Reynolds Numbers ◽

Aerodynamic Characteristics ◽

Strength Analysis ◽

Aerodynamic Design ◽

Lattice Method ◽

Vortex Lattice Method ◽

Analysis And Design ◽

Moment Coefficient ◽

Wing Geometry ◽

Design Requirements

The paper presents an aerodynamic analysis of a one-seat ultralight (UL) tailless aeroplane named L2k, with a very complicated layout. In the first part, an autostable airfoil with a low moment coefficient was chosen as a base for this problem. This airfoil was refined and modified to satisfy the design requirements. The computed aerodynamic characteristics of the airfoils for different Reynolds numbers (Re) were compared with available experimental data. XFOIL code was used to perform the computations. In the second part, a computation of wing characteristics was carried out. All calculated cases were chosen as points on the manoeuvring and gust envelope. The vortex lattice method was used with consideration of fuselage and winglets for very complicated wing geometry. The PMW computer program developed at IAE was used to perform the computations. The computed results were subsequently used for structural and strength analysis and design.

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