COMPARATIVE STUDY OF WING LIFT DISTRIBUTION ANALYSIS USING NUMERICAL METHOD

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.

Download Full-text

Geometrically exact vortex lattice and panel methods in static aeroelasticity of very flexible wing

Proceedings of the Institution of Mechanical Engineers Part G Journal of Aerospace Engineering ◽

10.1177/0954410019885238 ◽

2019 ◽

Vol 234 (3) ◽

pp. 742-759

Author(s):

Lan Yang ◽

Changchuan Xie ◽

Chao Yang

Keyword(s):

Large Deformation ◽

Vortex Lattice ◽

Panel Method ◽

Theoretical Research ◽

Full Potential ◽

Geometrically Nonlinear ◽

Lattice Method ◽

Vortex Lattice Method ◽

Aeroelastic Analysis ◽

Nonlinear Static

Geometrically exact vortex lattice method and panel method are presented in this paper to deal with aerodynamic load computation for geometrically nonlinear static aeroelastic problems. They are combined with geometrically nonlinear finite element method through surface spline interpolation in the loosely-coupled iteration. From the perspective of theoretical research, both vortex lattice method and panel method are based on the full potential equation and able to model the deflection and twist of the wing, while vortex lattice method is based on the thin airfoil theory, and panel method is suitable for thick wings. Although the potential flow equation is linear, the introduction of geometrically exact boundary conditions makes it significantly different from the linear aeroelastic analysis. The numerical results of a high aspect ratio wing are provided to declare the influence of large deformation on nonlinear static aeroelastic computation compared with linear analysis. Aeroelastic analyses based on geometrically exact vortex lattice method and panel method are also compared with the results of computational fluid dynamics/computational structural dynamics coupling method and the wind tunnel test data. The nonlinear static aeroelastic analysis agrees with the measurement even in considerably large deformation situations.

Download Full-text

Use of CFD Techniques in the Preliminary Design of Upwind Sails

10.5957/csys-1999-011 ◽

1999 ◽

Author(s):

Patrick Couser ◽

Norm Deane

Keyword(s):

South Africa ◽

Numerical Methods ◽

Research And Development ◽

Computational Methods ◽

Vortex Lattice ◽

Development Programme ◽

Preliminary Design ◽

Lattice Method ◽

Vortex Lattice Method ◽

Water Testing

The results of the 1997 World Titles, held in Kingston, Canada, highlighted that there was considerable scope for improving the upwind performance of the international Mirror Class by making small adjustments, within the tolerances allowed by the class rule, to the sails and underwater foils. This paper describes some aspects of the Australian research and development programme in preparation for the 1999 World Titles to be held in South Africa in April. Computational methods, based on the vortex lattice method, have been used to provide direction and guidance for the on-the-water testing and trialing programme. The use of these theoretical tools has enabled a far wider range of sail, dagger board and rudder parameters to be investigated than would be possible using purely on-the-water testing. The usefulness of well-understood computational and numerical methods in sail and foil design has been demonstrated; it has also been shown that these tools are within the reach of relatively small budget research and development programmes. The proof of the pudding may be at the 1999 International Mirror Class World Titles ... (watch this space)

Download Full-text

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

The Aeronautical Journal ◽

10.1017/aer.2020.128 ◽

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.

Download Full-text

A Combined Vortex Lattice Lifting Line Method for Unsteady Propeller Calculations

10.1115/omae2021-61807 ◽

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.

Download Full-text

Coupling a Numerical Optimization Technique with a Panel Method or a Vortex Lattice Method to Design Cavitating Propellers in Non-Uniform Inflows

Proceedings of the 10th International Symposium on Cavitation (CAV2018) ◽

10.1115/1.861851_ch54 ◽

2018 ◽

pp. 282-287

Keyword(s):

Numerical Optimization ◽

Vortex Lattice ◽

Optimization Technique ◽

Panel Method ◽

Lattice Method ◽

Vortex Lattice Method

Download Full-text

Comparison of Flow-Solvers: Linear Vortex Lattice Method and Higher-Order Panel Method with Analytical and Wind Tunnel Data

2020 3rd International Conference on Computing, Mathematics and Engineering Technologies (iCoMET) ◽

10.1109/icomet48670.2020.9073909 ◽

2020 ◽

Author(s):

Tahura Shahid ◽

Faiza Sajjad ◽

Muneeb Ahsan ◽

Syed Farhan ◽

Shuaib Salamat ◽

...

Keyword(s):

Wind Tunnel ◽

Vortex Lattice ◽

Higher Order ◽

Panel Method ◽

Lattice Method ◽

Vortex Lattice Method ◽

Wind Tunnel Data

Download Full-text

Generalized vortex lattice method for planar supersonic flow

AIAA Journal ◽

10.2514/3.13655 ◽

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

Download Full-text

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

International Journal of Aerospace Engineering ◽

10.1155/2019/5847627 ◽

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.

Download Full-text

Closed-Form Expressions for Numerical Evaluation of Self-Impedance Terms Involved on Wire Antenna Analysis by the Method of Moments

Electronics ◽

10.3390/electronics10111316 ◽

2021 ◽

Vol 10 (11) ◽

pp. 1316

Author(s):

Carlos-Ivan Paez-Rueda ◽

Arturo Fajardo ◽

Manuel Pérez ◽

Gabriel Perilla

Keyword(s):

Numerical Integration ◽

Method Of Moments ◽

Computing Time ◽

Basis Functions ◽

Wire Antenna ◽

Complex Geometries ◽

Point Matching ◽

Piecewise Constant ◽

Matching Procedure ◽

Time Required

This paper proposes new closed expressions of self-impedance using the Method of Moments with the Point Matching Procedure and piecewise constant and linear basis functions in different configurations, which allow saving computing time for the solution of wire antennas with complex geometries. The new expressions have complexity O(1) with well-defined theoretical bound errors. They were compared with an adaptive numerical integration. We obtain an accuracy between 7 and 16 digits depending on the chosen basis function and segmentation used. Besides, the computing time involved in the calculation of the self-impedance terms was evaluated and compared with the time required by the adaptative quadrature integration solution of the same problem. Expressions have a run-time bounded between 50 and 200 times faster than an adaptive numerical integration assuming full computation of all constant of the expressions.

Download Full-text