Flow over an airfoil

Aim - Make a case study and understand that, how different angle of attacks affects the drag force and lift.

Objective - Our objective here is to Modle an Airfoil and vary the angle of attacks from 0 to 10 with the difference of 2 units, and compare the Drag Force (Df) and Lift.

Geometry -

Steps -

• Insert the text file from he provided link in discription, convert the spline into a sketch using the convert entities button and then join the two open ends of the spline at the tail end of the airfoil using a line
• Make suret to turn on FLOW SIMULATION Add - in, and move fourther in the Simulation.
• Since it is an Flow over the foil, make sure we select External Flow in flow wizard and then select time dependnecy, fluid used is air having a density of 1.225 kg/m^3 and velocity of air in x-direction be given as 600 m/s. Other are se default.
• Before meching, we need to make sure that our Computational domain is 2-D in X-Y plane.
• After setting up computational domain large enough that the flow dosent affect the boundaries, build up the basic mesh and Refine the mesh gird near the surace for better results (build a local mesh at the surface of the airfoil as the basic mesh is not a body fitted mesh).
• Run the Simulation.
• Then create a cut plot to get the velocity profile
• Then using the goal from the insert data tree get the results for global goal and surface goal i.e, lift force and drag force.

Observations -

Case - 1

Angle of Attack = 0 Degree

Pressure - 76236 Pa - 481780 Pa

Df = 162.2 N

Lift Force = approx 0

Case - 2

Angle of Attack = 2 Dgrees

Presssure = 69643.5 Pa - 505442 Pa

Df = 175 N

Lift Force = 377 N

Case - 3

Angle of Attack = 4 Degrees

Pressure = 59354 Pa - 497123 Pa

Df = 211 N

Lift Force = 788.9 N

Case - 4

Angle of Attack = 6 Degrees

Pressure = 53292 Pa - 589369 Pa

Df = 276.8 N

Lift Force = 1198.6 N

Case - 5

Angle of Attack = 8 Degrees

Presssure = 47385.7 Pa - 612237 Pa

Df = 376.5 N

Lift Force = 1559 N

Case - 6

Angle of Attack = 10 Degrees

Presssure = 36386 Pa - 499647 Pa

Df = 503.2 N

Lift Force = 2021.8 N

Conclusion -

• In Case 1 we can see the pressure profile seems symmetric and since there can be no lift generated we gtting lift force nearly 0 N.
• As we move further in cases we can observe that, as AoA (Angle of Attack) increases Drag force as well as Lift force is increasing, reason of which is because the profile of Air Coil is opposing the flow, which results in pressure build up on the lower end causing Force in upwords direction.
• Decrease in maximum pressure is observed after 2 degrees, whereas maximum pressure increases from 0 degree to 2 degrees.

Air Foil taken in above case study is provided in Challenges section of Skill - Lync.