scholarly journals Fast and accurate quasi-3D aerodynamic methods for aircraft conceptual design studies

2020 ◽  
pp. 1-25
Author(s):  
O. Şugar-Gabor ◽  
A. Koreanschi
Keyword(s):  
Computational Time ◽  
Shape Optimisation ◽  
Surface Geometry ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Recent Developments ◽  
Line Theory ◽  
Lifting Surfaces ◽  
3D Methods ◽  
Aircraft Conceptual Design

ABSTRACT In this paper, recent developments in quasi-3D aerodynamic methods are presented. At their core, these methods are based on the lifting-line theory and vortex lattice method, but with a relaxed set of hypotheses, while also considering the effect of viscosity (to a certain degree) by introducing a strong non-linear coupling with two-dimensional viscous aerofoil aerodynamics. These methods can provide more accurate results compared with their inviscid classical counterparts and have an extended range of applicability with respect to the lifting surface geometry. Verification results are presented for both steady-state and unsteady flows, as well as case studies related to their integration into aerodynamic shape optimisation tools. The good accuracy achieved using relatively low computational time makes such quasi-3D methods a solid choice for conducting conceptual-level design and optimisation of lifting surfaces.

scholarly journals COMPARATIVE STUDY OF WING LIFT DISTRIBUTION ANALYSIS USING NUMERICAL METHOD

2020 ◽  
Vol 18 (2) ◽  
pp. 129
Author(s):  
Angga Septiyana ◽  
Ardian Rizaldi ◽  
Kurnia Hidayat ◽  
Yusuf Giri Wijaya
Keyword(s):  
Numerical Methods ◽  
Lift Force ◽  
Computing Time ◽  
Panel Method ◽  
Force Distribution ◽  
Distribution Analysis ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Line Theory ◽  
Time Required

This research focuses on calculating the force distribution on the wings of the LSU 05-NG aircraft by several numerical methods. Analysis of the force distribution on the wing is important because the wing has a very important role in producing sufficient lift for the aircraft. The numerical methods used to calculate the lift force distribution on the wings are Computational Flow Dynamics (CFD), Lifting Line Theory, Vortex Lattice Method and 3D Panel Method. The numerical methods used will be compared with each other to determine the accuracy and time required to calculate wing lift distribution. Because CFDs produce more accurate estimates, CFD is used as the main comparison for the other three numerical methods. Based on calculations performed, 3D Panel Method has an accuracy that is close to CFD with a shorter time. 3D Panel Method requires 400 while CFD 1210 seconds with results that are not much different. While LLT and VLM have poor accuracy, however, shorter time is needed. Therefore to analyze the distribution of lift force on the wing it is enough to use the 3D Panel Method due to accurate results and shorter computing time.

scholarly journals A general numerical unsteady non-linear lifting line model for engineering aerodynamics studies

2018 ◽  
Vol 122 (1254) ◽  
pp. 1199-1228 ◽  
Author(s):  
O. Sugar-Gabor
Keyword(s):  
Steady State ◽  
Line Model ◽  
Wide Range ◽  
Non Linear ◽  
Line Theory ◽  
Lifting Surfaces ◽  
Turbine Blade Design ◽  
Force Calculation ◽  
Aircraft Conceptual Design ◽  
Lifting Line

ABSTRACTThe lifting-line theory is widely used for obtaining aerodynamic performance results in various engineering fields, from aircraft conceptual design to wind-power generation. Many different models were proposed, each tailored for a specific purpose, thus having a rather narrow applicability range. This paper presents a general lifting-line model capable of accurately analysing a wide range of engineering problems involving lifting surfaces, both steady-state and unsteady cases. It can be used for lifting surface with sweep, dihedral, twisting and winglets and includes features such as non-linear viscous corrections, unsteady and quasi-steady force calculation, stable wake relaxation through fictitious time marching and wake stretching and dissipation. Possible applications include wing design for low-speed aircraft and unmanned aerial vehicles, the study of high-frequency avian flapping flight or wind-turbine blade design and analysis. Several validation studies are performed, both steady-state and unsteady, the method showing good agreement with experimental data or numerical results obtained with more computationally expensive methods.

Aerodynamic model of propeller–wing interaction for distributed propeller aircraft concept

2019 ◽  
Vol 234 (10) ◽  
pp. 1688-1705 ◽  
Author(s):  
Baizura Bohari ◽  
Quentin Borlon ◽  
Murat Bronz ◽  
Emmanuel Benard
Keyword(s):  
Experimental Data ◽  
Vortex Lattice ◽  
Numerical Models ◽  
Aircraft Design ◽  
Computational Time ◽  
Nonlinear Prediction ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Blade Element Theory ◽  
Aerodynamic Model

The present investigation addresses two key issues in aerodynamic performance of a propeller–wing configuration, namely linear and nonlinear predictions with low-order numerical models. The developed aerodynamic model is targeted to be used in the preliminary aircraft design loop. First, the combination of selected propeller model, i.e. blade element theory with the wing model, i.e. lifting line theory and vortex lattice method is considered for linear aerodynamic model. Second, for the nonlinear prediction, a modified vortex lattice method is paired with the two-dimensional viscous effect of the airfoils to simplify and reduce the computational time. These models are implemented and validated with existing experimental data to predict the differences in lift and drag distribution. Overall, the predicted results show agreement with low percentage of error compared with the experimental data for various thrust coefficients and produced induced drag distribution that behaves as expected.

A Combined Vortex Lattice Lifting Line Method for Unsteady Propeller Calculations

2021 ◽  
Author(s):  
Andreas Büsken ◽  
Stefan Krüger
Keyword(s):  
Vortex Lattice ◽  
Suction Side ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Vortex Model ◽  
Coupling Strategy ◽  
Line Theory ◽  
Lifting Line ◽  
Oseen Vortex ◽  
Lifting Line Method

Abstract This paper presents a Combined Method for the calculation of propeller forces in inhomogeneous inflow. It consists of an extended Goldstein approach based on Lifting Line Theory and a Vortex Lattice Method. After a brief overview of both methods is given, the coupling strategy is described and the additional modifications are explained. A correction factor accounting for the vortex which develops under a separated and later reattached flow on the suction side of the propeller blade is implemented as the first modification. Further, the Lamb-Oseen vortex model is used for the vortices in the free vortex system of the propeller. Finally, some results achieved with the described method are presented and compared to measured values.

Calculation of the Aerodynamic Forces on Automotive Lifting Surfaces

1985 ◽  
Vol 107 (4) ◽  
pp. 438-443 ◽  
Author(s):  
J. Katz
Keyword(s):  
Steady State ◽  
Vortex Lattice ◽  
Numerical Technique ◽  
Angle Of Attack ◽  
Ground Effect ◽  
Aerodynamic Forces ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Close Proximity ◽  
Lifting Surfaces

A numerical technique was developed to investigate the performance of automotive lifting surfaces in close proximity to ground. The model is based on the Vortex Lattice Method and includes freely-deforming wake elements. The ground effect was simulated by reflection and both steady and unsteady pressures and loads on various wing planforms were considered. Calculated results are presented for wings having both positive and negative incidences, with and without ground effect. Also the transient lift of a wing in a plunging motion was analyzed in ground proximity and at a negative angle of attack. Finally the periodic lift fluctuations on the front winglet of a racing car, due to its suspension oscillations, were calculated and found to exceed approximately twice the steady-state value.

Propeller influence on the aeroelastic stability of High Altitude Long Endurance aircraft

2020 ◽  
Vol 124 (1275) ◽  
pp. 703-730 ◽  
Author(s):  
P.C. Teixeira ◽  
C.E.S. Cesnik
Keyword(s):  
High Altitude ◽  
Data Series ◽  
Aeroelastic Stability ◽  
Time Data ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Lifting Surfaces ◽  
Structural Case ◽  
The Stability ◽  
Long Endurance

AbstractThis work investigates the propeller’s influence on the stability of High Altitude Long Endurance aircraft, incorporating all resultant loads at the propeller hub, propeller slipstream, and gyroscopic loads. Such effects are usually neglected in the aeroelastic simulation of HALE aircraft. For that goal, a previously developed framework, which couples a geometrically nonlinear structural solver with an Unsteady Vortex Lattice method (uVLM) for lifting surfaces and a Viscous Vortex Particle (VVP) method for propeller slipstream, was employed to generate time-data series. Also, a method, based on a combination of Proper Orthogonal Decomposition and system identification, to extract dynamic information (frequencies, damping, and modes) of the aircraft from a time-series signal is proposed and successfully tested for a purely structural case, for which reference data is available. The method is then applied to investigate the stability of aeroelastic cases. The results demonstrate that the presence of propellers can influence the aeroelastic stability of a Very Flexible Aircraft.

Generalized vortex lattice method for planar supersonic flow

AIAA Journal ◽  
1997 ◽  
Vol 35 ◽  
pp. 1230-1233
Author(s):  
Paulo A. O. Soviero ◽  
Hugo B. Resende
Keyword(s):  
Supersonic Flow ◽  
Vortex Lattice ◽  
Lattice Method ◽  
Vortex Lattice Method

scholarly journals Static Aeroelastic Characteristics of Morphing Trailing-Edge Wing Using Geometrically Exact Vortex Lattice Method

2019 ◽  
Vol 2019 ◽  
pp. 1-15
Author(s):  
Sen Mao ◽  
Changchuan Xie ◽  
Lan Yang ◽  
Chao Yang
Keyword(s):  
Vortex Lattice ◽  
Deflection Angle ◽  
Aircraft Design ◽  
Analysis Method ◽  
Lattice Method ◽  
Trailing Edge ◽  
Vortex Lattice Method ◽  
Analysis And Design ◽  
Aeroelastic Analysis ◽  
Typical Model

A morphing trailing-edge (TE) wing is an important morphing mode in aircraft design. In order to explore the static aeroelastic characteristics of a morphing TE wing, an efficient and feasible method for static aeroelastic analysis has been developed in this paper. A geometrically exact vortex lattice method (VLM) is applied to calculate the aerodynamic forces. Firstly, a typical model of a morphing TE wing is chosen and built which has an active morphing trailing edge driven by a piezoelectric patch. Then, the paper carries out the static aeroelastic analysis of the morphing TE wing and corresponding simulations were carried out. Finally, the analysis results are compared with those of a traditional wing with a rigid trailing edge using the traditional linearized VLM. The results indicate that the geometrically exact VLM can better describe the aerodynamic nonlinearity of a morphing TE wing in consideration of geometrical deformation in aeroelastic analysis. Moreover, out of consideration of the angle of attack, the deflection angle of the trailing edge, among others, the wing system does not show divergence but bifurcation. Consequently, the aeroelastic analysis method proposed in this paper is more applicable to the analysis and design of a morphing TE wing.

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