Flow over an airfoil

Aim:

To analyze the ow over a NACA0017 airfoil For different angle of attacks and to compare the lift and drag forces.

Objectives:

• To do a CFD analysis of a NACA0017 airfoil.
• Use different different angle of attacks for the airfoil as 0, 2, 4, 6, 8 & 10 degrees.
• Run the flow analysis to obtain Velocity contour and the drag force as well as lift force plots.
• Run the study for the time for which a constant behaviour of drag force is achieved.

Introduction:

Computational uid dynamics (CFD) is a branch of uid mechanics that uses numerical analysis and data structures to analyze and solve problems that involve fluid flows. Computers are used to perform the calculations required to simulate the free-stream ow of the uid, and the interaction of the fluid (liquids and gases) with surfaces dened by boundary conditions. Here Solidworks ow simulation is used for simulation.

Theory:

The NACA airfoils are airfoil shapes for aircraft wings developed by the National Advisory Committee for Aeronautics (NACA). The shape of the NACA airfoils is
described using a series of digits following the word "NACA". The parameters in the numerical code can be entered into equations to precisely generate the
cross-section of the airfoil and calculate its properties.

The NACA four-digit wing sections dene the prole by:

1. First digit describing maximum camber as percentage of the chord.
2. Second digit describing the distance of maximum camber from the airfoil leading edge in tenths of the chord.
3. Last two digits describing maximum thickness of the airfoil as percent of the chord.

parameters

1. External surface analysis is done for time dependent condition having total time = 5 sec. & Output time steps = 1 sec.
2. Air is selected as the ow component having 600 m/s velocity in the X direction.
3. The Computation domain is enlarged by 5 times in chord for input & 10 times in chord for output.
4. Surface goals selected as Force (X) & Force (Y) for external face.
5. Then the model is rotated by 0, 2, 4, 6, 8 & 10 degrees as the different conditions to analyze the effect of rotation.

Steps:

1. Insert the NACA airfoil .txt le from the airfoil database provided.
2. Sketch the airfoil by connecting the ends
3. Extrude the airfoil and save it.
4. Activate the ow simulation and add the parameters in the wizard command.
5. Select 2D computational domain and increase the domain size
6. Edit the global mesh into ne mesh and local mesh at the face of the curve for renement.
7. Set surface goals to get the drag and lift force.
8. Run the simulation
9. Insert plots of pressure and velocity
10. Insert goals from results to get drag and lift force results.

creating model

for angle of attack 0 degree

plots

drag force and lift force

data obtained

for angle of attack 2 degree

plots

drag force and lift force

data obtained

for angle of attack 4 degree

plots

drag force and lift force

data obtained

for angle of attack 6 degree

plots

drag force and lift force

data obtained

for angle of attack 8 degree

plots

drag force and lift force

data obtained

for angle of attack 10 degree

plots

drag force and lift force

data obtained

Conclusion:

So we can see that as the angle of attack increases the lift force on the surface also increases.And overall we can see the increase in the size of the wake region as the angle of attack increases. We can see the change in the position of the stagnation point.