CFD simulation on Flow over a NACA0017 airfoil
AIM: To model the flow over NACA0017 airfoil and compare the lift and drag force for the angle of attack 0,2,4,6,8,10.
INTRODUCTION
The NACA airfoils are the 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"
Fig1: NACA0017 Airfoil
NACA 4 digit airfoil specification
The NACA airfoil series is controlled by 4 digits e.g. NACA 2412, which designate the camber, position of the maximum camber and thickness. If an airfoil number is NACA MPXX e.g.NACA 2412 then:
M is the maximum camber divided by 100. In the example M=2 so the camber is 0.02 or 2% of the chord
P is the position of the maximum camber divided by 10. In the example P=4 so the maximum camber is at 0.4 or 40% of the chord.
XX is the thickness divided by 100. In the example XX=12 so the thickness is 0.12 or 12% of the chord.
PROCEDURE
1) Download the curve of NACA0017 from Airfoil database, then insert the curve in SOLIDWORKS make sure the dimension system is in MKS.
2) Convert the curve into a sketch and join ends of the curve by a line to make the curve close.
3) Rotate the curve in desired Angel of attack like 0,2,4,6,8,10 individually in different simulations then extrude and save the file.
4) Run Wizard and set the required conditions like External Flow, Transient simulation, air as working medium and velocity in X-axis was given as 600m/s.
5) Increase the domain length 5times the chord length of the airfoil at entry and 10-15 times at the exit of the airfoil.
6) As the mesh is not body fitted mesh hence introduce a local surface mesh to increase the refinement at the surface of the airfoil.
Fig1: Cutshell Cartesian Mesh
Fig2: Refinement by Local mesh
7) Set surface goal, select force at X and Y which indicates Drag and Lift force respectively.
8) Run the simulation and get the desired results for each Angle of Attack.
OUTPUT & RESULTS
0 Degree Angle of attack
Velocity Profile-
Pressure profile-
Drag force & Lift force comparison-
SG Force (X)1 denotes Surface Goal force at X axis which is called as Drag Force.
SG Force (Y)1 denotes Surface Goal Force at Y axis which is called as Lift Force.
Average Drag Force = 1293 N
Average Lift Force = 0.624 N
2 Degree Angle of attack
Velocity profile-
Pressure profile-
Drag force & Lift force comparison-
SG Force (X)1 denotes Surface Goal force at X axis which is called as Drag Force.
SG Force (Y)1 denotes Surface Goal Force at Y axis which is called as Lift Force.
Average Drag Force = 1298 N
Average Lift Force = 610 N
4 Degree Angle of attack
Velocity profile-
Pressure profile-
Drag force & Lift force comparison-
SG Force (X)1 denotes Surface Goal force at X axis which is called as Drag Force.
SG Force (Y)1 denotes Surface Goal Force at Y axis which is called as Lift Force.
Average Drag Force = 1361 N
Average Lift Force = 1244 N
6 Degree Angle of attack
Velocity profile-
Pressure profile-
Drag force & Lift force comparison-
SG Force (X)1 denotes Surface Goal force at X axis which is called as Drag Force.
SG Force (Y)1 denotes Surface Goal Force at Y axis which is called as Lift Force.
Average Drag Force = 1454 N
Average Lift Force = 1895 N
8 Degree Angle of attack
Velocity profile-
Pressure profile-
Drag force & Lift force comparison-
SG Force (X)1 denotes Surface Goal force at X axis which is called as Drag Force.
SG Force (Y)1 denotes Surface Goal Force at Y axis which is called as Lift Force.
Average Drag Force = 1588 N
Average Lift Force = 2483 N
10 Degree Angle of attack
Velocity profile-
Pressure profile-
Drag force & Lift force comparison-
SG Force (X)1 denotes Surface Goal force at X axis which is called as Drag Force.
SG Force (Y)1 denotes Surface Goal Force at Y axis which is called as Lift Force
Average Drag Force = 1668 N
Average Lift Force = 2955 N
Drag force vs Angle of attack graph
Lift force vs Angle of attack graph
CONCLUSION
1) Drag force and lift force increases as the angle of attack increases.
2) Lift force is nearly equal to zero in case of zero degree angle of attack.
3) Symmetry in velocity and pressure profile is seen in the zero degree angle of attack.
4) We can observe a little drop in pressure as the angle of attack increases.
5) Refinement of mesh near the surface of the airfoil is extremely necessary to get the optimum results.
6) There is not much difference in the values of Global goal and surface goal as we can see from force comparison table in 10 degrees Angle of Attack case, values for both are nearly the same.