Surface Modifications for Improved Maneuverability and Performance of an Aircraft

Aircraft Wing ◽

Pressure Drag ◽

Wing Model ◽

Study Results ◽

Stall Angle ◽

And Performance ◽

The work describes a comparative study of aerodynamic characteristics of an aircraft wing model with and without surface modifications to it. The surface modifications that are considered here are outward dimples on the wing model. In the present study, results of computational fluid dynamics (CFD) analysis are presented showing variance in lift and drag of modified wing models at different angle of attacks. Dimples on the surface aircraft wing model doesn’t affect much the pressure drag since it’s already aerodynamic in shape but it can affect the angle of stall. This project verifies if the dimples that reduce a golf ball’s drag, can also increase an airplane’s critical angle of stall. Dimples delay the boundary layer separation by creating more turbulence over the surface. The airfoil profile considered here is NACA-0018 with uniform cross-section throughout the length of airfoil. Subsonic flows are considered for the study. The CAD model is prepared in CatiaV5 R18 and simulations are carried out in Comsol 3.4 and Comsol 4.0. The overall aim of the study is improved maneuverability and performance of an aircraft. The results justify the increase in the overall lift and reduction in drag of the aircraft, also change of stall angle with different surface modifications on the wing model is observed.

Cavity for Flow Control and Performance Improvement of Airfoil

10.1115/gtindia2021-76415 ◽

2021 ◽

Author(s):

Anand Verma ◽

Bastav Borah ◽

Vinayak Kulkarni

Keyword(s):

Moving Boundary ◽

Flow Analysis ◽

Leading Edge ◽

Suction Surface ◽

Confined Spaces ◽

Steady Simulation ◽

And Performance ◽

Lift And Drag ◽

Fluid Flow Analysis

Abstract The fluid flow analysis over a cambered airfoil having three different cavity locations on the suction surface is reported in this paper. The Elliptical cavity is created at LE, MC, and TE along chordwise locations from the leading to trailing edge. In this regard, the steady simulation is carried out in the Fluent at Reynolds number of 105 based on their chord length. The lift and drag characteristics for clean and cavities airfoil are investigated at different angles of attack. For the clean airfoil, the stall point is observed at 18°. The presence of a cavity improves the stall and aerodynamic characteristics of airfoil. It has been seen that the lift and drag coefficients for pre-stalled or lower angles are nearly similar to clean and cavity at MC or TE positions. For the post-stall point, the improvement in the aerodynamic performance is seen for the cavity at MC or TE. The cavity placed at LE produces lower lift and higher drag characteristics against other configuration models. The overall cavity effect for the flow around the airfoil is that it creates vortices, thereby re-energizes the slower moving boundary layer and delays the flow separation in the downstream direction. The outcomes of this analysis are suggested that the cavity at a position before the mid chord from the leading edge does not improve the performance of the airfoil. Though vortex is formed in the confined spaces but it is unable to reattach the flow towards the downstream direction of an airfoil.

Aerodynamic Analysis of a Flapping Wing Aircraft for Short Landing

Applied Sciences ◽

10.3390/app10103404 ◽

2020 ◽

Vol 10 (10) ◽

pp. 3404

Author(s):

Bing Ji ◽

Zenggang Zhu ◽

Shijun Guo ◽

Si Chen ◽

Qiaolin Zhu ◽

...

Keyword(s):

Flapping Wing ◽

Aerodynamic Analysis ◽

Drag Forces ◽

Wing Model ◽

Aerodynamic Model ◽

Computational Fluid Dynamics Cfd ◽

The Difference ◽

Cfd Method ◽

An investigation into the aerodynamic characteristics has been presented for a bio-inspired flapping wing aircraft. Firstly, a mechanism has been developed to transform the usual rotation powered by a motor to a combined flapping and pitching motion of the flapping wing. Secondly, an experimental model of the flapping wing aircraft has been built and tested to measure the motion and aerodynamic forces produced by the flapping wing. Thirdly, aerodynamic analysis is carried out based on the measured motion of the flapping wing model using an unsteady aerodynamic model (UAM) and validated by a computational fluid dynamics (CFD) method. The difference of the average lift force between the UAM and CFD method is 1.3%, and the difference between the UAM and experimental results is 18%. In addition, a parametric study is carried out by employing the UAM method to analyze the effect of variations of the pitching angle on the aerodynamic lift and drag forces. According to the study, the pitching amplitude for maximum lift is in the range of 60°~70° as the flight velocity decreases from 5 m/s to 1 m/s during landing.

A Research on Wind Tunnel on Drag Reduction in Aircraft Wing by Inducing Surface Roughness

International Journal of Recent Technology and Engineering - 2 ◽

10.35940/ijrte.b1005.0782s319 ◽

2019 ◽

Vol 8 (2S3) ◽

pp. 25-28

Keyword(s):

Surface Roughness ◽

Wind Tunnel ◽

Viscous Drag ◽

Friction Drag ◽

Aircraft Wing ◽

Aerodynamic Efficiency ◽

Stall Angle ◽

Lift And Drag ◽

Naca 0012 ◽

Inducing Surface

Drag is a major issue that aircraft industries are facing today. Innumerable investigations are in progress which mainly focus on the methods to reduce drag. Improving the aerodynamic efficiency of the vehicle can resolve this drawback to a great extent. The aerodynamic efficiency is explained in L/D ratio, decreasing the drag component will increase the aerodynamic efficiency. In this research a methodology to reduce the drag by creating roughness over wing surface has been adopted. By adopting this surface roughness method, the transition of the air flow from the laminar to the turbulent region will result in less drag. This research is being carried out based on the above said theory. The outcome of this method can delay the flow separation in a wing which helps in increasing the lift. The roughness has reduced the coefficient of skin friction drag or viscous drag and increased the coefficient of lift along with the stall angle of attack. NACA 0012 airfoil was selected for this study. Aluminum wing models are fabricated with and without surface roughness and same has been tested in Wind Tunnel. The results are discussed in terms of Lift and Drag

Design and Construction of NACA-4415 Airfoil with Various Shaped Surface Modifications

10.20944/preprints201704.0124.v1 ◽

2017 ◽

Author(s):

Rubiat Mustak

Keyword(s):

Flow Direction ◽

Surface Modifications ◽

Flowing Fluid ◽

Pressure Drag ◽

Wing Model ◽

Real Model ◽

Viscous Shear ◽

C Programming ◽

Digit Series ◽

Solid Works

A fluid flowing over an object has a tendency to drag the object along it’s flow direction. An object passing through a fluid which is stationary there is a tendency to slow the object down. For a stationary object in a fluid which is flowing there is a tendency to move the object in the fluid flowing direction .These tendencies of flowing fluid is known as drag. While moving through air airplanes also subjected to several drags. Airplanes subjected to pressure drag or form drag due to flow separation which is based on the pressure difference between the upstream and downstream surfaces of the object. Airplanes also subjected to Skin friction drag which results from the viscous shear of the fluid flowing over the object surface. In order to overcome these drags airplane wings cross section airfoils are designed very carefully. National Advisory Committee for Aeronautics, or NACA, developed and tested "families" of airfoils. Some of the most successful of these were the NACA four-digit and five-digit series. The necessary coordinates for designing NACA airfoil profiles are available in online. UIUC also provide coordinates for designing NACA airfoil profiles. But the present work describes the way of designing NACA four digit airfoils without taking any coordinates from available sources like google or any other search engines. Using C programming with the help of NACA provided equations a generalized source code is designed .Which will provide coordinates for designing any NACA four digit airfoil profiles .With the help of this obtained profile the wing model is also constructed using solid works. Using solid works model the real model was constructed using wood. The chord of regular surface airfoil is 21 cm and the span is also 21 cm. The airfoil profile taken for the model construction is NACA-4415 which is a four digit cambered airfoil.The present work also show some figures of an airfoil by applying certain surface modifications in form of dimples.

Volume 8: Energy Systems: Analysis, Thermodynamics and Sustainability; Sustainable Products and Processes ◽

Selection of Airfoils for Straight-Bladed Vertical Axis Wind Turbines Based on Desirable Aerodynamic Characteristics

10.1115/imece2008-66027 ◽

2008 ◽

Cited By ~ 2

Author(s):

Mazharul Islam ◽

M. Ruhul Amin ◽

David S.-K. Ting ◽

Amir Fartaj

Keyword(s):

Urban Areas ◽

Lift Coefficient ◽

Vertical Axis ◽

Performance Indices ◽

Niche Markets ◽

Design Changes ◽

Stall Angle ◽

Lift And Drag ◽

Selection Of

Selection of the airfoil is crucial for better aerodynamic performance and dimensions of a smaller-capacity SB-VAWT which can compete with conventional energy sources in niche markets like urban areas and off-grid remote applications for diversified applications. Airfoil related design changes also have the potential for increasing the cost effectiveness of VAWTs. Recently, Islam et. al [1] have identified the desirable features of an ideal airfoil for smaller capacity SB-VAWT to improve its starting characteristics and overall performance. They have shortlisted several aerodynamic characteristics of the desirable airfoil. Based on these desirable aerodynamic characteristics, an attempt has been made in this paper to shortlist ten prospective candidate airfoils for smaller-capacity SB-VAWT. This is done using both experimental and analytical characteristics. Nine performance indices have been defined in this paper in light of desirable aerodynamic characteristics to select best performing airfoil. These performance indices are utilized for considering the following desirable aerodynamic characteristics: (i) stall angle at low Reynolds number, (ii) width of the drag bucket, (iii) zero-lift-drag coefficient, (iv) Cl/Cd ratio, (v) maximum lift-coefficient, (vi) deep-stall angle, (vii) roughness sensitivity, (viii) trailing edge noise generation, and (ix) pitching moment. Here, Cl and Cd are coefficients of lift and drag respectively. After determining the value of the performance indices and rating of the candidate airfoils, the most promising airfoil is selected. Among the ten candidate airfoils, overall rating of NASA LS(1)-0417 has been found to be the best.

Analysis of the Flow Characteristics of Two Nonrotating Rotor Blades

Journal of Solar Energy Engineering ◽

10.1115/1.2931507 ◽

2008 ◽

Vol 130 (3) ◽

Cited By ~ 3

Author(s):

R. P. J. O. M. van Rooij

Keyword(s):

Aspect Ratio ◽

Dominant Role ◽

Flow Characteristics ◽

Leading Edge ◽

Rotor Blades ◽

Drag Coefficients ◽

Wing Model ◽

Stall Angle ◽

Twisted Blade ◽

The investigation focuses on the analysis of the airfoil segment performances along rotor blades in the parked configuration. In this research, wind tunnel experiments on two twisted blade geometries with different airfoils played a dominant role. These measurements were carried out by the Swedish Aeronautical Research Institute, former FFA, and by the American National Renewable Energy Laboratories (NREL) during the Unsteady Aerodynamic Experiment. The spans of the blades were 2.375m and 5m, the STORK 5 WPX and the NREL Phase VI blade, respectively. Five span locations (inboard, midspan, outboard, and tip regions) were considered and compared with the 2D airfoil characteristics. Wing model experiments with similar blade aspect ratio were included in the research. Furthermore, the commercial computational fluid dynamics code FLUENT was used for the validation and analysis of the spanwise lift and drag coefficients at four different pitch settings, 20deg, 30deg, 45deg, and 60deg. The computed pressure distributions compared reasonably well, but the derived lift and drag showed quite some differences with the blade measurements. The lift coefficients for the sections beyond the leading-edge stall angle of the STORK blade were larger than for the NREL blade and were close to that of a wing model with similar airfoil and aspect ratio. Lift and drag coefficients for the sections of the two blades were always much smaller than the 2D results. The drag values for both blades showed quite some agreement, and airfoil and blade dependency seemed to be small.

The Analysis about External Compressible Flow around an Aircraft Wing

Advanced Materials Research ◽

10.4028/www.scientific.net/amr.1044-1045.654 ◽

2014 ◽

Vol 1044-1045 ◽

pp. 654-658

Author(s):

Wei Long ◽

Zai Shuai Ling ◽

Zhen Dang

Keyword(s):

Flow Field ◽

Velocity Vector ◽

Delta Wing ◽

Angle Of Attack ◽

Flow Simulation ◽

Aircraft Wing ◽

Wing Model ◽

Fluent Simulation ◽

Lift And Drag ◽

Variation Tendency

The Steady flow simulation to selected the delta wing model for different angles of attack in the Maher number.The law of flow field changes with the angle of attack is gotten.Through the FLUENT simulation,The variation tendency of coefficient of lift and drag in the different angle of attack is gotten.Further reveals the change rule of Maher number, pressure, velocity and other parameters in the different angle of attack.With increasing angle of attack, Maher number distribution is sparse of the same position increases and the greater numerical.the distribution of velocity vector is sparse of the same position increases and the greater numerical.the pressure distribution is sparse of the same position increases and the greater numerical.

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 ◽

Airfoil Surface ◽

Wing Geometry ◽

Stall Angle ◽

Finite Wing ◽

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.