Project BOGO: Research and Design of a Two- Stage Supersonic Rocket ME Senior Design/Honors Project 4600:497-001 Group Members: Matthew Reppa Harrison Lewis James Gase Ryan Hannaford Page 1 This report documents the design process for a supersonic two-stage rocket and highlights the team’s research, design, testing, and construction of key elements of the rocket. Most major systems of the launch vehicle, including motors, electronics systems, interior and exterior structures, and recovery, will be analyzed and assessed during the design process. The launch vehicle is set was intended to compete at the 2020 Spaceport America Cup in Las Cruces, New Mexico prior to the shutdown of the competition due to the COVID-19 epidemic. Undergoing this project allowed the team members to further develop the skills learned throughout the Mechanical Engineering and Aerospace Systems Engineering curriculums at the University of Akron. Additionally, the findings of this report will provide a basis for future innovation within the University of Akron’s Akronauts Rocket Design Team. Page 2 TABLE OF CONTENTS 1. Abstract .............................................................................................................................. 2 2. Introduction ......................................................................................................................... 7 2.1. Background.................................................................................................................. 7 2.2. Spaceport America Cup ............................................................................................... 8 2.3. Requirements .............................................................................................................. 8 2.3.1. University of Akron ME Department Requirements ............................................... 8 2.3.2. University of Akron Honors College Requirements ............................................... 8 2.3.3. Experimental Sounding Rocket Association Requirements ................................... 9 2.3.4. Team Derivation Requirements ............................................................................ 9 2.4. Objectives ...................................................................................................................12 2.5. Solution .......................................................................................................................12 2.6. Reasoning ..................................................................................................................13 3. Structural Design ...............................................................................................................15 3.1. Nose Cone Design ......................................................................................................15 3.1.1. Nose Cone Shape ...............................................................................................15 3.1.2. Fineness Ratio .....................................................................................................17 3.1.3. Manufacturability ..................................................................................................17 3.1.4. Simulation Analysis ..............................................................................................19 3.1.5. Nose Cone Temperature Calculations .................................................................20 3.2. Fin Design ..................................................................................................................20 3.2.1. Number of Fins ....................................................................................................21 3.2.2. Leading-Edge Design ..........................................................................................22 3.2.3. Trailing-Edge Design ...........................................................................................24 3.2.4. Airfoil Manufacturing ............................................................................................27 3.2.5. Computational Fluid Dynamic Analysis ................................................................28 3.2.6. Final Fin Design ...................................................................................................36 3.2.7. Flutter Analysis ....................................................................................................36 3.2.8. Modal Analysis .....................................................................................................38 3.3. Fin Retention ..............................................................................................................40 3.3.1. Design Factors .....................................................................................................40 Page 3 3.3.2. Printed Canister ...................................................................................................48 3.3.3. External Fin Retainer ...........................................................................................50 3.3.4. Internal Hardware Retainer ..................................................................................51 3.3.5. Tapered Inserts ....................................................................................................52 3.3.6. Tangential Screw Alignment ................................................................................53 3.3.7. Final Design .........................................................................................................54 3.4. Bulkheads & Centering Rings .....................................................................................55 3.5. Motor Retention ..........................................................................................................56 3.5.1. Retention Options ................................................................................................56 3.5.2. Thread Engagement ............................................................................................58 3.5.3. Krushnic Effect .....................................................................................................60 3.6. Rail buttons .................................................................................................................61 3.6.1. Rail Button Placement .........................................................................................61 3.6.2. Rail Button Attachment ........................................................................................62 4. Rocket Staging Techniques ...............................................................................................64 4.1. Rocket Layout .............................................................................................................64 4.2. Stage Separation ........................................................................................................64 4.2.1. Constant vs Varying Diameter .............................................................................64 4.2.2. Passive vs Forced Separation .............................................................................66 4.2.3. Potential Fin Attachment Issues ...........................................................................68 4.3. Motor Selection ...........................................................................................................69 4.4. Sustainer Separation & Ignition Timing .......................................................................71 4.4.1. Altitude and Velocity Analysis ..............................................................................72 4.4.2. Vertical Orientation Analysis ................................................................................75 4.4.3. Drift Analysis ........................................................................................................78 4.5. Max Dynamic Force Calculations ................................................................................80 4.6. Parachute Deployment Methods and Layouts .............................................................82 4.6.1. Tender Descender ...............................................................................................83 4.6.2. Jolly Logic ............................................................................................................84 4.6.3. Third Electronics Bay ...........................................................................................84 4.7. Sustainer Ignition Avionics ..........................................................................................86 4.7.1. Tiltmeter Selection ...............................................................................................86 4.7.2. EasyMega Functionality .......................................................................................87 Page 4 4.7.3. Sustainer Ignition Arming .....................................................................................91 4.7.4. Sustainer Avionics Wiring ....................................................................................91 5. Recovery Systems .............................................................................................................95 5.1. Altimeters ....................................................................................................................95 5.2. Stage Separation Timers ............................................................................................97 5.3. GPS ............................................................................................................................98