Flow over an airfoil

AIM :

CFD analysis of flow over NACA AIRFOIL with different angle of attack of 0 2 4 6 8 10 degree.The simulation was done using SolidWorks flow simulation.

OBJECTIVE :

Model the flow over a NACA0017 airfoil

For the angle of attacks 0,2,4,6,8,10 compare the lift and drag forces.

INTRODUCTION :

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.

GEOMETRY CREATION :

The co-ordinates points of the curve was downloaded from the database link provided. We used xyz curve to create the airfoil shape. ( insert – xyz points – browse – select the file (txt format ) – open – ok ).Now the airfoil-shaped curve is formed. Just close the loop at the end using line command. At this point, the angle of attack is 0 degree. We have 5 more case with an angle of attack (2,4,6,8,10).To give this angle of attack to the geometry we have to rotate this geometry. Use rotate entities for rotating at different angles.

FLOW SIMULATION :

• Create a new wizard for every case. Use the default unit system.
• Next, select the external flow as we are doing external flow analysis.
• This study will be time dependent we will be performing the experiment for the total of 5 sec and the time step will be 1 sec.
• We are taking air as our working fluid medium.
• Next, we have to give velocity for this air-flow in the x-direction with the magnitude of 600 m/s.

Computational domain :

Meshing and goals :

The basic mesh was looking good so no changes were made. But we have to refine cells at the extruded surface which is 1mm long. So to do this we have to add the local mesh. (Select the surface -refining level (3).In this study, we are mainly focusing on the drag and lift forces so we have insert global and surface goals for this.

RESULTS :

case 1 - angle of attack 0 degree

case 2 - angle of attack 2 degree

case 3 - angle of attack 4 degree

case 4 - angle of attack 6 degree

case 5 - angle of attack 8 degree

case 6 - angle of attack 10 degree

sg force x - drag force overall on the extruded surface which we selected for local mesh

sg force y - lift force overall on the extruded surface which we selected for local mesh

Case 1 - angle of attack 0 degree

Pressure cut plot

Velocity cut plot :

Goals plot results :

Case 2 - angle of attack 2 degree :

Pressure cut plot

Velocity cut plot :

Goals plot results :

Case 3 - angle of attack 4 degree :

Pressure cut plot

Velocity cut plot :

Goals plot results :

Case 4 - angle of attack 6 degree :

Pressure cut plot

Velocity cut plot :

Goals plot results :

Case 5 - angle of attack 8 degree :

Pressure cut plot

Velocity cut plot

Goals plot results :

Case 6 - angle of attack 10 degree :

Pressure cut plot

Velocity cut plot

Goals plot results :

CONCLUSION :

With the increase in angle of attack, the number of iterations required to give the result get reduced.

With the increase in angle of attack, Drag force increases slowly and lift force increases rapidly.

With the increase in angle of attack, the velocity of air over the airfoil increased.