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Lighter Than Air Critical Design Review. The A-Team. Mark Cote Yonas Tesfaye Josh Levinger Bryan Owens. Presentation Objectives. Introduce Final Design Scale drawings of final design Control systems of final design Aerodynamic analysis of final design Final design evolution and analysis.
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Lighter Than AirCritical Design Review The A-Team Mark Cote Yonas Tesfaye Josh Levinger Bryan Owens
Presentation Objectives • Introduce Final Design • Scale drawings of final design • Control systems of final design • Aerodynamic analysis of final design • Final design evolution and analysis
Final Design • Linear • Pros: • Reliable and well tested • Low drag profile • Stability • Simplicity • Expandable • Cons • Difficult to maneuver • Large structure requirement • Unwieldy (N-body problem)
Scale Drawings Front View Courtesy: Mark Cote
Scale Drawings Side View Courtesy: Mark Cote
Scale Drawings Bottom View Courtesy: Mark Cote
Control Systems We will be using two servos to steer. The motors are in line and the front motor will be used to steer left and right. The rear motor will be used to control pitch. We will also have rear stabilizers.
Circuit Diagram Courtesy: Josh Levinger
Materials ObjectQuantityMass (g) Large Motor 2 420.0 Propellers 2 15.9 Receivers 1 27.0 Servos 1 43.0 Battery pack 1 148.0 Balloons 3 210.0 Structure 1 175.0 Total Weight : ~ 1040 g Total Payload: ~ 710 g
Aerodynamic Analysis =1.773 m3 1 balloon = .524 m3 3 balloons overfilled should support the weight. Lift generated by three normal balloons: 15.205 N Overfilling Balloons: 17.150 N We believe that we will average 2/3 of the maximum thrust throughout the course for a velocity of 2.09 m/s. We believe our blimp will be able to complete the course in 42 seconds.
Final Design Evolution and Analysis Originally, we had decided on a triangle design with differential steering. Our first concern was in regards to drag because it had profile drag of about two balloons as which meant we would be fighting twice as much drag. Top View Front View Courtesy: Mark Cote
Analysis Cont’d We also realized that with differential steering, we would lose a significant amount of thrust.