Drag Queen LTA Completed Design Review Nestor Lara, 2004
Drag Queen Nestor Lara Chicago, Illinois Alice Fan Orlando, Florida Benjamin Feinberg Lawrenceville, New Jersey Matt Williams Battle Creek, Michigan Hyon Lee Windsor, Canada Nikhil (friend of group), 2004
Table of Contents IntroductionObjectives Selection of Final Design Schematics of Final Design Control Systems Aerodynamic Analysis Weekly Timeline ConclusionIIIIIIIVVVIVIIVII
Objectives To discuss the procedure and final selection of Drag Queen structure To discuss the procedure and final selection of Drag Queen structure To provide analysis regarding the components and method of functioning of the final design To provide analysis regarding the components and method of functioning of the final design To accurately analyze the aerodynamics of the final design To accurately analyze the aerodynamics of the final design To present a final design that will work based upon correct calculations To present a final design that will work based upon correct calculations Ben Feinberg, 2004
Final Design – Intro PDR DesignCDR Design 3 balloons assembled in row3 balloons assembled on triangular frame 3 motors: 2 large, 1 small3 motors: 2 large, 1 small Long, thinCompact, tight Advantages:Advantages: Somewhat stableStronger structure Lift can be adjustedLess wobbly in turns Simpler StructureLess chance for ‘rollover’ AerodynamicSymmetrical sides are possibility Less risk in turns, greater mobility Disadvantages:Disadvantages: Unstable in turns “Rollover” capabilitiesLarger Drag (but low speeds) Unoriginal
Final Design Features Symmetry Triangular symmetry desired, but too complicated Triangular symmetry desired, but too complicated Established ‘front’ and ‘back’ to triangular LTA Established ‘front’ and ‘back’ to triangular LTAStructure 2 triangles (.9m sides) were assembled atop one another 2 triangles (.9m sides) were assembled atop one another Between triangles is balsa wood to create durable and strong structure Between triangles is balsa wood to create durable and strong structureElectronics Triangular structure allows all electric motors to be relatively close to one another Triangular structure allows all electric motors to be relatively close to one another 1 small motor (altitude) in front, 2 large motors (thrust, steering) in each back corner 1 small motor (altitude) in front, 2 large motors (thrust, steering) in each back corner Wires originate and join battery pack on platform in middle of LTA Wires originate and join battery pack on platform in middle of LTAPower Altitude: Power comes from small motor in front Altitude: Power comes from small motor in front Thrust: both large motors powered at same speed Thrust: both large motors powered at same speed Steering: with one motor / propeller fixed and one free to rotate, greater torque can be created in desired direction when turning Steering: with one motor / propeller fixed and one free to rotate, greater torque can be created in desired direction when turning
Final Design – Scale Drawing Hyon Lee, 2004
Control Systems 4 Controls 1. Speed of Motor 1 (rear left) 2. Speed of Motor 2 (rear right) 3. Rotation of Motor 2 4. Altitude Controls 1 and 2 The speed of each motor’s propeller is independent of one another Thus, differential steering is possible Control 3 Motor 2 is on a swivel: when pointed straight ahead its range is 90 degrees to the left or 90 degrees to the right To add to the idea of differential steering, this will provide greater torque in direction of steering Control 4 Self-explanatory Used to provide lift and keep LTA stable in case of uneven air conditions
Control Systems DRAG QUEEN Features Our LTA is capable of differential steering and thrusting and also makes use of a rotating motor. With only 4 controls on the transmitter, we are effectively and efficiently using all controls to create a working LTA.
Control Systems – Schematic Hyon Lee, 2004
Aerodynamic Analysis Note: Some values taken from Interactive Aerospace Engineering and Design: D. Newman ItemQuantity Unit Wt. Total Wt. Balloon3 70 g 210 g Large Motor / Propeller g 420 g Small Motor / Propeller 1 90 g AA Battery 4 50 g 200 g Receiver1 27 g Receiver Battery 1 94 g Servos1 43 g Total 1284 g Structural Frame g PayloadTBD Drag Queen Total Mass : 1377 g Vehicle Mass Limit : 1750 g
Aerodynamic Analysis Thrust based on 9V battery Helium Volume Required: Lift From Volume Thrust:
Aerodynamic Analysis Vehicle Velocity: Vehicle Drag: Endurance: (Based on battery life and change of volume of balloons during flight) With Non-Perfect Flight, we estimated the endurance of 1 round trip would be:
Drag Queen Timeline Alice Fan, 2004
Conclusion By analyzing various designs and assessing the strength and weaknesses of each, we were able to select a design that provides optimal reliability and efficiency. The incorporation of two large motors allows for better maneuverability and maximum thrust, while the small motor underneath the vehicle allows for stability and lift control. The lightweight design contributes to the improved aerodynamics of the vehicle and provides greater support to the frame of the dirigible. Thus, these features of our team's LTA make it highly competitive and give us the leading edge.
Good Luck Drag Queen