PFR - Aerospace Engineering Sciences Senior Design Projects ...

More documents

Recommendations

Info

Project Final Report – CUDBF April 30 th , 2009 ASEN 4028: Aerospace Senior Projects Figure 128: Competition lap flown on flight test #7 After the successful completion of flight test #7, without any pilot complaints, flight test #8 was conducted using the full four rocket payload (6.0 lbs of total payload). The goal of this flight was to collect data on takeoff speed, landing speed, and average current draw. Takeoff and landing speed were predicted using 1.3*Vstall. With the four rocket payload, takeoff and landing speed were predicted to be 35 mph. Takeoff speed was 35 mph, and landing speed occurred at 33 mph. Figure 129: Flight pictures from flight test #8 The average current draw was 21.9 amps, slightly above the 20 amps predicted. A plot of the predicted versus actual current draw is shown in Figure 130. The blue line represents the predicted value, and the red line represents the actual value. The small discrepancy can be attributed to variations in pilot flying style. The average speed during the flight was 44.8 mph, very close to the 43 mph average speed during the empty flight. This data confirms that the pilot chose to fly at a constant airspeed, rather than a constant power setting. Ultimately, all these values proved to be close to the predicted values. Flight test #8 ended with a broken nose gear upon landing. 144
Project Final Report – CUDBF April 30 th , 2009 ASEN 4028: Aerospace Senior Projects 60 50 Power Profile Actual Predicted Amp Draw (amps) 40 30 20 10 0 0 50 100 150 200 250 300 350 Time (seconds) Figure 130: Actual versus predicted amp draw on flight test #8 13.2.2.7 Flight Test #9 The purpose of flight test #9 was to fly the aircraft under asymmetric loads. This flight would test the asymmetric load for the smallest lateral CG shift. The configuration was two rockets: one inboard on one wing, and the other rocket outboard on the other wing. This resulted in a lateral CG shift of 0.9”. A diagram of the loading is shown in Figure 131. Figure 131: Asymmetric loading for flight test #9 During the taxi test before the flight, the pilot noticed a significant lack of ground control. The nose gear twisted in one direction, and the servo was unable to turn the wheel in the other direction. To compensate for the lack of steering, it was decided to use elevator on takeoff to reduce the load on the nose gear and steer using the rudders. This method is commonly used by small aircraft for soft field takeoffs. However, this caused the aircraft to lift off at 25 mph instead of the predicted 30 mph takeoff speed. In addition to being slow, the aircraft took off at a very steep angle. This caused the aircraft to stall shortly after liftoff. The aircraft then rolled the opposite direction of the pull of the asymmetric load, and then crashed. This resulted in the loss of the Buff-2A, the aerodynamic prototype. 145
Page 1:
University of Colorado Design/Build
Page 4 and 5:
Project Final Report - CUDBF April
Page 6 and 7:
Page 8 and 9:
Page 10 and 11:
Page 12 and 13:
Page 14 and 15:
Page 16 and 17:
Page 18 and 19:
Page 20 and 21:
Page 22 and 23:
Page 24 and 25:
Page 26 and 27:
Page 28 and 29:
Page 30 and 31:
Page 32 and 33:
Page 34 and 35:
Page 36 and 37:
Page 38 and 39:
Page 40 and 41:
Page 42 and 43:
Page 44 and 45:
Page 46 and 47:
Page 48 and 49:
Page 50 and 51:
Page 52 and 53:
Page 54 and 55:
Page 56 and 57:
Page 58 and 59:
Page 60 and 61:
Page 62 and 63:
Page 64 and 65:
Page 66 and 67:
Page 68 and 69:
Page 70 and 71:
Page 72 and 73:
Page 74 and 75:
Page 76 and 77:
Page 78 and 79:
Page 80 and 81:
Page 82 and 83:
Page 84 and 85:
Page 86 and 87:
Page 88 and 89:
Page 90 and 91:
Page 92 and 93:
Page 94 and 95:
Page 96 and 97: Project Final Report - CUDBF April
Page 166: Project Final Report - CUDBF April
show all

PFR - Aerospace Engineering Sciences Senior Design Projects ...

Create successful ePaper yourself

Delete template?

Save as template?