Overview
The project goal is to analyze and recreate an airfoil based on the NACA number. Then test and record the airfoil in simulated conditions. Then create an airfoil and test it to see if it matched the characteristics of its simulated counterparts.
Air tractor 602
"The AT-602 is designed for operators needing more than 500 gallons, but less than the 800-gallon AT-802. It takes just one load to spray a 125-acre circle at 5 gallons per acre. Ferry times are shortened by its powerful PT6A-60AG engine. The AT-602 is the perfect match of hopper capacity to engine performance. The 602 lets operators streamline from a multi-plane to a single-plane operation with plenty of productivity, reduced overhead and better profit margins."
http://www.airtractor.com/aircraft/602
http://www.airtractor.com/aircraft/602
Air Foil Data
Air Foil Simulation
The NASA FoilSim applet calculates the lift of an airfoil based on user inputs of flow conditions and wing geometry. We used the NACA number (4415) to set the shape of the airfoil. The first number (4) represents the camber, the last two digits (15) represents the thickness. The size of the simulate airfoil is the same as the test airfoil (4" chord and 4" span). The flight conditions are set at 60 mph and the altitude is at 0. The data is recorded with the Angle of Attack is set to -20 and the Final Angle of Attack to 20 and the Angle of Attack Step to 5 degrees. Complete Foilsim Excel chart is below.
Construction
Construction of the airfoil was acheived by sandwiching 2 inches of foam between identical airfoil cross-sections made of 3/16" plywood. The foam was then cut out and sanded to match the cross-sections, and then the cross sections were removed and mounting clip was attatched. The scaled profile of the airfoil were used to create the cross-section pieces that served as the guideline for the airfoil itself.
The airfoil was put into a wind tunnel and tested from -20 degrees Angle of Attack to +20 degrees Angle of Attack at 5 degree increments. Before testing, the same experiment
was performed using the NASA Foilsim app set to the exact same conditions to calculate the lift/drag coefficient. Since it is a ratio, the scaling of the airfoil should have no effect on the outcome.
was performed using the NASA Foilsim app set to the exact same conditions to calculate the lift/drag coefficient. Since it is a ratio, the scaling of the airfoil should have no effect on the outcome.
Test Results
Conclusion
1. Explain differences between the airfoil simulation prediction and the wind tunnel test results.
The differences between the airfoil simulation and wind tunnel are that they both had different outcomes for the lift and drag.
2. What characteristic of the airfoil had the most significant impact on lift and drag?
The most signifigant characteristics that impacted the airfoil
was how well it was evenly flatened and cut out, meaning no bumps or loppsided ends.
3. Explain what you would change in the design of your airfoil design?
I would change the uneven trailing edge at the back so it was even. I would also recut the air foil so that its not caved in.
The differences between the airfoil simulation and wind tunnel are that they both had different outcomes for the lift and drag.
2. What characteristic of the airfoil had the most significant impact on lift and drag?
The most signifigant characteristics that impacted the airfoil
was how well it was evenly flatened and cut out, meaning no bumps or loppsided ends.
3. Explain what you would change in the design of your airfoil design?
I would change the uneven trailing edge at the back so it was even. I would also recut the air foil so that its not caved in.