scholarly journals Aerodynamic Design of a Tailless Aeroplan

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.

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.

An Analytic and Experimental Investigation of the Aerodynamic Performance Enhancements of Multiple Winglet Configurations

2005 ◽  
Author(s):  
D. S. Miklosovic ◽  
P. M. Bookey
Keyword(s):  
Aspect Ratio ◽  
Vortex Lattice ◽  
Dihedral Angles ◽  
Pitching Moment ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Moment Coefficient ◽  
Effectiveness And Efficiency ◽  
Low Speed Wind Tunnel ◽  
Experimental Effort

An experimental effort was undertaken to assess the effectiveness and efficiency of three winglets mounted chordwise to the tip of a rectangular wing (NACA 0018 section). The winglets, with an aspect ratio of 3.6, were mounted on a half-span wing having an aspect ratio of 3.1. Twenty configurations of varying dihedral arrangements were analyzed with a vortex lattice method and tested in a low-speed wind tunnel at a Reynolds number of 600,000. In general, the arrangements involving high dihedral angles had lower performance increments, due to lower lift and higher interference drag. More specifically, the results showed that the winglets placed at 60, 45, and 30 degrees, respectively, produced nominal 4% higher lift and 46% lower drag. The most dramatic findings from this study show that positioning the winglet dihedral angles had the result of adjusting the point of maximum L/D and the magnitude of the pitching moment coefficient. These observations suggest that multiple winglet dihedral changes affect the lift, drag, and pitching moment in such a way that they are feasible for use as actively-controlled surfaces to improve the performance of aircraft at various flight conditions and to “tune” the longitudinal stability characteristics of the wing.

scholarly journals Analytic determination of tandem-scheme aircraft aerodynamic characteristics

2015 ◽  
pp. 59-71
Author(s):  
Ілля Станіславович Кривохатько ◽  
Віталій Вікторович Сухов
Keyword(s):  
Mathematical Model ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Design ◽  
New Approach ◽  
Definite Integrals ◽  
Moment Coefficient ◽  
Numerical Computing ◽  
Theoretical Results

In present article analytic method of downwash after wing, lift coefficient and pitching moment coefficient determination for tandem-scheme aircraft was upgraded. Mathematical model is based on Bio-Savart formula and avoid approximate calculus of indefinite integrals in contrast to classical theory. Instead of it new approach consists on numerical computing of definite integrals with high accuracy (error less than 10­-5 was achieved). Method is appropriate for low Mach number and for any Reynolds number. Theoretical results calculated according to proposed method were compared with wind tunnel experiment data and showed good agreement.Developed mathematical model allows optimization of tandem-scheme aircraft aerodynamic design with different objective function. In the next works method will be expanded on the lateral aerodynamic characteristics.

Analysis of aerodynamic characteristics using the vortex lattice method on twin tail boom unmanned aircraft

2020 ◽  
Author(s):  
A. Septiyana ◽  
K. Hidayat ◽  
A. Rizaldi ◽  
M. L. Ramadiansyah ◽  
R. A. Ramadhan ◽  
...  
Keyword(s):  
Vortex Lattice ◽  
Aerodynamic Characteristics ◽  
Unmanned Aircraft ◽  
Lattice Method ◽  
Vortex Lattice Method

Analytic and Experimental Investigation of Dihedral Configurations of Three-Winglet Planforms

2008 ◽  
Vol 130 (7) ◽  
Author(s):  
David S. Miklosovic
Keyword(s):  
Aspect Ratio ◽  
Lift Coefficient ◽  
Pitching Moment ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Moment Coefficient ◽  
Velocity Circulation ◽  
Low Speed Wind Tunnel ◽  
Experimental Effort ◽  
Good Agreement

An analytic and experimental effort was undertaken to assess the effectiveness and efficiency of three winglets mounted chordwise to the tip of a rectangular wing. The winglets, with an aspect ratio of 4.6, were mounted on a half-span wing having an effective aspect ratio of 6.29. 13 configurations of varying dihedral arrangements were analyzed with a vortex lattice method and tested in a low-speed wind tunnel at a Reynolds number of 600,000. While the analytic method provided fair agreement with the experimental results, the predicted trends in lift, drag, and (to a lesser degree) pitching moment were in good agreement. The analytic distributions of wake velocity, circulation, and downwash angle verified that highly nonplanar configurations tended to reduce and diffuse the regions of highest circulation and to create more moderate downwash angles in the wake. This was manifest as an overall drag reduction. More specifically, the results showed that the winglets could be placed in various optimum orientations to increase the lift coefficient as much as 65% at the same angle of attack, decrease the drag coefficient as much as 54% at the same lift coefficient, or improve the maximum L∕D by up to 57%. The most dramatic findings from this study show that positioning the winglet dihedral angles had the result of adjusting the magnitude and slope of the pitching moment coefficient. These observations suggest that multiple winglet dihedral variations may be feasible for use as actively controlled surfaces to improve the performance of aircraft at various flight conditions and to “tune” the longitudinal stability characteristics of the configuration.

scholarly journals On Boeing 737 – 300 Wing Aerodynamics Calculations Based on VLM Theory

2018 ◽  
Vol 1 (1) ◽  
pp. 95
Author(s):  
Jacob Nagler
Keyword(s):  
Vortex Lattice ◽  
Center Of Pressure ◽  
Location Error ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Wing Geometry ◽  
Finite Wing ◽  
Using Data ◽  
Wing Aerodynamics

<p>In this paper, aerodynamics coefficients of Boeing 737-300 were calculated using VLM (vortex lattice method) theory. The wing was assumed to be planar and was divided into 6×6 panels, which were in the trapezoid shape. Aerodynamics lifting and moment coefficients were calculated. Also, center of pressure location was found using data from VLM and wing geometry. Comparisons between literature, finite wing theory and VLM theory were done. It was found that maximum lifting coefficient error between literature and VLM was about 4.0%. Moreover, that between finite wing theory and VLM was about 2.2%. Center of pressure location error between finite wing theory and VLM was about 0.5%.</p>

scholarly journals Airfoil Analysis and Effect of Wing Shape Optimization on Aerodynamic Parameters in a Steady Flight

2021 ◽  
pp. 43-53
Author(s):  
Vishu K. Oza ◽  
Hardik R. Vala
Keyword(s):  
Lattice Method ◽  
Vortex Lattice Method ◽  
Layer Analysis ◽  
Tail Structure ◽  
Aerial Vehicle ◽  
Wing Geometry ◽  
Aerodynamic Parameters ◽  
Improved Performance ◽  
The Impact ◽  
Drag Ratio

The work in this paper deals with reconstructing and optimizing the wing geometry of an Unmanned Combat Aerial Vehicle for improved performance and reviewing the impact of the modification on flight parameters in a steady flight. The behavior of airfoils at planned flight conditions under I.S.A. is checked in XFLR5 software. Following up by 2-D CFD and boundary layer analysis of former and new airfoil, dimensions of the wing are re-developed, keeping the fuselage and tail structure same. The existing wing and the optimized wing design is analyzed by Vortex Lattice Method and Triangular Panel Method, with an objective to make the shape of the wing aerodynamically suitable for an increased Lift to Drag ratio and thereby minimizing drag coefficients.

scholarly journals On the aerodynamic interactions analysis between the main rotor and the helicopter fuselage

10.29007/3m41 ◽  
2020 ◽  
Author(s):  
Thanh Dong Pham ◽  
Anh Tuan Nguyen ◽  
Ngoc Thanh Dang ◽  
Vu Uy Pham
Keyword(s):  
Aerodynamic Characteristic ◽  
Vortex Lattice ◽  
Aerodynamic Characteristics ◽  
Main Rotor ◽  
Lattice Method ◽  
Vortex Lattice Method ◽  
Wake Model ◽  
Helicopter Main Rotor ◽  
Flight Regimes ◽  
Free Wake

This paper develops a numerical method that is capable of analyzing the aerodynamic characteristic of the helicopter main rotor in consider the influence of fuselage. The method is based on an unsteady nonlinear vortex-lattice method that can be used to simulate the interactions among the helicopter components efficiently. To clarify the effect of the main rotor-fuselage interaction, the aerodynamic characteristics of the main rotor in consider the influence of fuselage is determined along with those of the combined main rotor-fuselage system. The paper also shows the velocity field and free wake model in several flight regimes. The fuselage is modeled as a streamlined object, which is discretized into the system of quadrilateral vortex panels. The no-penetration boundary condition is satisfied on the fuselage surface, and no vorticity is shed from the fuselage. The results obtained in this paper are validated against experimental data and some from previous numerical methods.

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