Numerical Study on Aerodynamic Characteristics of NACA0015

2013 ◽  
Vol 302 ◽  
pp. 640-645
Author(s):  
Su Jeong Lee ◽  
Eui Chul Jeong ◽  
Hee Chang Lim
Keyword(s):  
Pressure Distribution ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
Surface Pressure Distribution ◽  
Maximum Value ◽  
Stall Angle ◽  
Near Wall

In this study, a numerical simulation is made to understand the effect of the angle of attack on a NACA airfoil, which will be used for a basic shape to apply for making the vertical axis Darius wind turbine. The near-wall y+ value which is less than 1 is known to be most desirable for a near-wall modeling. Therefore, this study is aiming to observe the variation and find the optimized value of y+. The Reynolds number used in this study was 360,000, where the chord length and the velocity were 0.12m and 43.8m/s, respectively. Generally, the lift coefficient of the airfoil tends to increase as the angle of attack increases and it decreases substantially at the stall angle and then it decreases. As expected, the lift coefficient increases rapidly from 0 to 10° and then after the sudden drop of the lift (i.e., the stall) at around 10 to 16° depending on the y+ value. In this paper, it seems to be reliable and appropriate to use y+ value close to 1. From the surface pressure distribution, from the result obtained the ratio of pressure distribution of maximum value to the minimum value was 1.89and these peaks move forward to backward as the angle of attack increases.

scholarly journals Analysis on Flow Field Characteristics of Airfoil in Pitching Motion

2021 ◽  
Vol 2076 (1) ◽  
pp. 012069
Author(s):  
Rui Yin ◽  
Jing Huang ◽  
Zhi-Yuan He
Keyword(s):  
Flow Field ◽  
Drag Coefficient ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Decisive Role ◽  
Aerodynamic Characteristics ◽  
Pitching Motion ◽  
Maximum Value ◽  
Flow Field Characteristics ◽  
Lift And Drag

Abstract Based on CFD, the flow field characteristics of NACA4412 airfoil are analyzed under pitching motion, and its aerodynamic characteristics are interpreted. The results show that streamline changes on the upper surface of the airfoil play a decisive role in the aerodynamic characteristics. The interaction between the vortex leads to fluctuations in the lift and drag coefficients. Under a big angle of attack, the secondary trailing vortex on the upper surface of the airfoil adheres to the trailing edge of the airfoil, resulting in an increased drag coefficient. Under a small angle of attack, the secondary trailing vortex can break away from the airfoil. The lift coefficient reaches the maximum value of 2.961 before the airfoil is turned upside down, and the drag coefficient reaches the maximum value of 1.515 after the airfoil is turned upside down, but the corresponding angles of attack of the two are equal.

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

2008 ◽  
Author(s):  
Mazharul Islam ◽  
M. Ruhul Amin ◽  
David S.-K. Ting ◽  
Amir Fartaj
Keyword(s):  
Urban Areas ◽  
Lift Coefficient ◽  
Vertical Axis ◽  
Aerodynamic Characteristics ◽  
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.

scholarly journals Numerical and experimental investigation of the flow separation over NREL's S822 aerofoil and its control by suction and blowing

2021 ◽  
Vol 6 ◽  
pp. 5
Author(s):  
Nazar Aldabash‎‎ ◽  
Andrew Wandel‎ ◽  
Abdul Salam Darwish‎ ◽  
Jayantha Epaarachchi‎
Keyword(s):  
Experimental Investigation ◽  
Wind Turbine ◽  
Flow Separation ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Volumetric Flow Rate ◽  
Aerodynamic Characteristics ◽  
Careful Selection ◽  
Suction And Blowing

In this study, a numerical and experimental investigation for the flow separation over 170 mm chord, the NREL S822 aerofoil low Reynolds number wind turbine blade aerofoil section has been investigated at 15.8 m/s wind speed using suction and blowing techniques for the locations between 0.15 and 0.41 of the chord to improve aerodynamic characteristics of a wind turbine rotor blade. In a numerical study, two-dimensional aerofoil (i.e. NREL S822), using Shear Stress Transport (SST (γ − Reθ)) turbulence model, is presented. Careful selection for the number of mesh was considered through an iterative process to achieve the optimum mesh number resulted in optimum values for the ratio of lift to drag coefficients (CL/CD). Values of the lift coefficient, drag coefficient, and separation location were investigated at an angle of attack 18°. Flow separation is monitored and predicted within the numerical results at the tested angles, which has been compared with the experimental results and should a fair agreement. The results revealed that the aerodynamic characteristics of NERL S822 aerofoil would be improved using the suction technique more than the suction and blowing techniques and there is a delay of flow separation with the increase of blowing or suction volumetric flow rate. Using these two techniques and careful selection of the mesh numbers with the right angle of attack can improve the aerofoil characteristics and therefore lead to improve the turbine performance characteristics.

Numerical Investigation of Flow past a Wavy Airfoil

2011 ◽  
Vol 110-116 ◽  
pp. 4269-4275
Author(s):  
K. Lam ◽  
Y.F. Lin ◽  
Y. Liu ◽  
L. Zou
Keyword(s):  
Numerical Investigation ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Aerodynamic Characteristics ◽  
Large Eddy Simulations ◽  
Wavy Surface ◽  
Naca0012 Airfoil ◽  
Large Eddy ◽  
Stall Angle ◽  
Coefficient Reduction

The effect of the wavy surface on the aerodynamic characteristics of an airfoil is studied using the large eddy simulations. A more gentle lift characteristic is obtained during stall. For angles of attack less than the baseline stall angle of a NACA0012 airfoil, a lift coefficient reduction was observed for the wavy airfoils, while the lift coefficient increases up to 23% greater than that of a NACA0012 airfoil when the angle of attack is larger than the baseline stall angle of the NACA0012 airfoil.

Research on Wind Turbine Airfoils Aerodynamic Performance of Trailing Edge Modification

2015 ◽  
Vol 741 ◽  
pp. 554-557
Author(s):  
Shang Ke Yuan ◽  
Zi Qin Zhao
Keyword(s):  
Pressure Distribution ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Trailing Edge ◽  
Airfoil Surface ◽  
Computation Result ◽  
Surface Pressure Distribution ◽  
Gurney Flap ◽  
Aerodynamic Performances ◽  
Turbine Airfoils

The airfoil commonly employed in wind turbines is modified by attaching a Gurney flap with length of 2% chord at its trailing edge and its remodeled form as well,but it showed special aerodynamic characteristics.The software FLUENT are respectively used to carry out numerical computation of aerodynamic performances of above-mentioned three airfoils, so that their aerodynamic characteristics, surface pressure distribution, and streamline around them are obtained for different angles of attack. It is shown by the computation result that the modified airfoils will result in such a strong downwash effect and the pressure distribution on airfoil surface is remarkably altered, the lift coefficient, and meantime the airfoil stalling is greatly postponed,but the airfoil of Gurney flap shown the characteristics of opposite.

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

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.

scholarly journals A STUDY OF HIGH LIFT AERODYNAMIC DEVICES ON COMMERCIAL AIRCRAFTS

Aviation ◽  
2020 ◽  
Vol 24 (3) ◽  
pp. 123-136
Author(s):  
Swamy Naidu Venkata Neigapula ◽  
Satya Prasad Maddula ◽  
Vasishta Bhargava Nukala
Keyword(s):  
Lift Coefficient ◽  
Angle Of Attack ◽  
Leading Edge ◽  
Trailing Edge ◽  
High Lift ◽  
Aircraft Wings ◽  
Surface Pressure Distribution ◽  
Trailing Edge Flaps ◽  
Stall Angle ◽  
Kinematic Mechanisms

Aerodynamic performance of aircraft wings vary with flight path conditions and depend on efficiency of high lift systems. In this work, a study on high lift devices and mechanisms that aim to increase maximum lift coefficient and reduce drag on commercial aircraft wings is discussed. Typically, such extensions are provided to main airfoil along span wise direction of wing and can increase lift coefficient by more than 100% during operation. Increasing the no of trailing edge flaps in chord wise direction could result in 100% increment in lift coefficient at a given angle of attack but leading edge slats improve lift by delaying the flow separation near stall angle of attack. Different combinations of trailing edge flaps used by Airbus, Boeing and McDonnel Douglas manufacturers are explained along with kinematic mechanisms to deploy them. The surface pressure distribution for 30P30N airfoil is evaluated using 2D vortex panel method and effects of chord wise boundary layer flow transitions on aerodynamic lift generation is discussed. The results showed better agreements with experiment data for high Reynolds number (9 million) flow conditions near stall angle of attack.

scholarly journals Numerical Investigation of M21 Aerofoil and Effect of Plain Flapper at Various Angle of Attack

2021 ◽  
Vol 2070 (1) ◽  
pp. 012153
Author(s):  
Vimal Patel ◽  
Vikram Rathod ◽  
Chirag Patel
Keyword(s):  
Drag Force ◽  
Lift Force ◽  
Lift Coefficient ◽  
Angle Of Attack ◽  
Similar Work ◽  
Maximum Value ◽  
Different Types ◽  
Stall Angle ◽  
Drag And Lift ◽  
Plane Jet

Abstract The aerofoil plays an important role in any structure moving in a fluid-like in a passenger plane, jet plane, or helicopter. The aerofoils decide whether the lift force is appropriate to balance the weight of the plane or not and the amount of drag force is required on the vehicle. The purpose of this project is to simulate the M21 Aerofoil with the help of FLUENT and validate it with theory. This Project also includes the study of various Flapper designs and their simulation. Flappers are useful when the Airplane is about to take-off or landing. The Important parameters to be study are Lift Force, Drag Force, lift coefficient, and Drag coefficient. Simulation has been done for the different Angle of Attack which is useful for finding maximum Lift force and Stall Angle. The Work includes simulation of Plain Flapper for the Angle of Attack where CL/CD is maximum. Similar work can be done for different types of Flapper used in Airplane. The stall angle achieved for M21 was 24° and maximum value of CL/CD measured at 7° A.O.A. Investigation also shows that for the 10° plain flap angle highest drag and lift force was possible. It contains the study of the Adverse Yaw effect which rolls the Airplane while taking a turn. since the validity of any theoretical prediction can only be assessed in practice.

A comprehensive numerical study of battle damage and repairs upon the aerodynamic characteristics of an aerofoil

2010 ◽  
Vol 114 (1158) ◽  
pp. 469-484 ◽  
Author(s):  
M. Saeedi ◽  
F. Ajalli ◽  
M. Mani
Keyword(s):  
Flow Field ◽  
Numerical Solution ◽  
Mesh Generation ◽  
Unstructured Mesh ◽  
Numerical Study ◽  
Lift Coefficient ◽  
Aerodynamic Characteristics ◽  
Experimental Results ◽  
The Other ◽  
Stall Angle

Abstract A NACA 641-412 aerofoil with circle and star damage and also three repair configurations has been numerically investigated. Two different methods of mesh generation were employed: multi structured mesh for the star damaged aerofoil and unstructured mesh for the other aerofoils. The results show that the damage will cause a reduction in lift coefficient of the aerofoil and also a different stall angle relative to that of the undamaged aerofoil. Each kind of repair improves the aerodynamic characteristics of the aerofoil considerably. The flow Field inside the damage hole and the cavity caused by the repair sheets was also investigated. Finally, the numerical solution was qualitatively and quantitatively validated using the available experimental results.

scholarly journals Effect of a Circular Slot on Hybrid Airship Aerodynamic Characteristics

Aerospace ◽  
2021 ◽  
Vol 8 (6) ◽  
pp. 166
Author(s):  
Sekar Mano ◽  
RadhaKrishnan Ajay Sriram ◽  
Ganesan Vinayagamurthy ◽  
Subramania Nadaraja Pillai ◽  
Amjad Ali Pasha ◽  
...  
Keyword(s):  
Numerical Study ◽  
Flow Behavior ◽  
Lift Coefficient ◽  
Pressure Coefficient ◽  
Suction Side ◽  
Aerodynamic Characteristics ◽  
Aerodynamic Properties ◽  
Slot Opening ◽  
Stall Angle ◽  
High Pressure Region

This numerical study reports the aerodynamic properties of a hybrid airship. The hybrid airships were designed by combining two semi-ellipsoids with a semi-discoid as the base model. From the base model, three different geometrics were identified to study their aerodynamic characteristics. A circular slot was provided between the pressure side and the suction side of the airship. The objective of this study was to realize the flow behavior, aerodynamic characteristics, and stability properties of such slotted hybrid flying vehicles. Interestingly, the results imply that the lift coefficient increases with an increase in the angle of attack for the slotted configurations; this is because the flow separation is delayed due to the slot opening, which in turn is due to the flow of energies from the high-pressure region to the bottom through the slots. The delayed stall angle was 50 degrees, which was 10% more than that of the base model. Aerodynamic characteristics are discussed based on surface pressure, coefficient of lift, and coefficient of drag for various slotted hybrid airships.

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