Flow over an airfoil
AIRFOIL SIMULATION AT DIFFERENT ANGLE OF ATTACK
AIM :- performing airfoil simulation of NACA 0017 airfoil and compare drag force for different angle of attack ( 0 , 2 , 4 , 6 , 8 , 10 )
An airfoil is the cross-sectional shape of a wing, blade (of a propeller, rotor, or turbine)
An airfoil-shaped body moving through a fluid produces an aerodynamic force. The component of this force perpendicular to the direction of motion is called lift. The component parallel to the direction of motion is called drag. Subsonic flight airfoils have a characteristic shape with a rounded leading edge, followed by a sharp trailing edge, often with a symmetric curvature of upper and lower surfaces. Foils of similar function designed with water as the working fluid are called hydrofoils.
In fluid dynamics angle of attack is the angle between a reference line on a body (often the chord line of an airfoil) and the vector representing the relative motion between the body and the fluid through which it is moving. Angle of attack is the angle between the body's reference line and the oncoming flow. This article focuses on the most common application, the angle of attack of a wing or airfoil moving through air.
In aerodynamics, angle of attack specifies the angle between the chord line of the wing of a fixed-wing aircraft and the vector representing the relative motion between the aircraft and the atmosphere. Since a wing can have twist, a chord line of the whole wing may not be definable, so an alternate reference line is simply defined. Often, the chord line of the root of the wing is chosen as the reference line. Another choice is to use a horizontal line on the fuselage as the reference line (and also as the longitudinal axis). do not use an arbitrary chord line but use the zero lift axis where, by definition, zero angle of attack corresponds to zero coefficient of lift.
The lift coefficient of a fixed-wing aircraft varies with angle of attack. Increasing angle of attack is associated with increasing lift coefficient up to the maximum lift coefficient, after which lift coefficient decreases.
As the angle of attack of a fixed-wing aircraft increases, separation of the airflow from the upper surface of the wing becomes more pronounced, leading to a reduction in the rate of increase of the lift coefficient. The figure shows a typical curve for a cambered straight wing. Cambered airfoils are curved such that they generate some lift at small negative angles of attack. A symmetrical wing has zero lift at 0 degrees angle of attack. The lift curve is also influenced by the wing shape, including its airfoil section and wing planform. A swept wing has a lower, flatter curve with a higher critical angle
Procedure :-
1 . import the NACA 0017 airfoil from coordinate data text file
2 . make model of NACA 0017 airfoil
3 . analysing the airfoil flow simulation for different angle of attack
4 . compare lifts and drag of different cases or at different angle of attack
Case 1 :- velocity and pressure plots at angle of attack 0 degree
Velocity profile at angle of attack 0 degree
Pressure at angle of attack 0 degree
Case 2 :- velocity and pressure plots at angle of attack 2 degree
Velocity profile at angle of attack 2 degree
Pressure at angle of attack 2 degree
Case 3 :- velocity and pressure plots at angle of attack 4 degree
Velocity profile at angle of attack 4 degree
Pressure at angle of attack 4 degree
Case 4 :- velocity and pressure plots at angle of attack 6 degree
Velocity profile at angle of attack 6 degree
Pressure at angle of attack 6 degree
Case 5 :- velocity and pressure plots at angle of attack 8 degree
Velocity profile at angle of attack 8 degree
Pressure at angle of attack 8 degree
Case 6 :- velocity and pressure plots at angle of attack 10 degree
Velocity profile at angle of attack 10 degree
Pressure at angle of attack 10 degree
Reference :-