Project SCOTTIE: Preliminary Design Review Carnegie Mellon Rocket - PowerPoint PPT Presentation

Project SCOTTIE: Preliminary Design Review Carnegie Mellon Rocket Command November 14, 2018

Table of Contents 1. Vehicle Overview ……………………………………………………………………………………………… 2 2. Apogee Targeting System …………………………………………………………………………………. 12 3. Recovery Subsystem ………………………………………………………………………………………... 19 4. Mission Performance Predictions ……………................................................................ 29 5. Payload Overview ……………………………………................................................................. 37 6. Requirements Compliance Plan ………………................................................................. 45 7. Logistics …………………………………………………………………………………………………………….. 49 1

Table of Contents 1. Vehicle Overview …………………………………………………………………………………………… 2 2. Apogee Targeting System …………………………………………………………………………………. 12 3. Recovery Subsystem ………………………………………………………………………………………... 19 4. Mission Performance Predictions ……………................................................................ 29 5. Payload Overview ……………………………………................................................................. 37 6. Requirements Compliance Plan ………………................................................................. 45 7. Logistics …………………………………………………………………………………………………………….. 49 2

Launch Vehicle Overview 3

General Dimensions Component Dimensions Mass (lb) Nose Cone 6” D x 24” L 2.08 Payload Bay 6” D x 10” L 4.11 Upper Airframe 6” D x 24” L 7.00 Recovery Bay 6” D x 6” L 2.98 Middle Airframe 6” D x 17” L 2.81 ATS Bay 6” D x 10” L 4.24 Lower Airframe 6” D x 35” L 10.94 Total 6” D x 115” L 33.8 (Dry), 41.7 (Wet) 4

Airframe Material Cost Density Ult. Tensile Stiffness (msi) (oz/in3) Strength (ksi) G-12 Fiberglass $3.80 1.23 60-80 5-10 Carbon Fiber $8.90 0.90 240 20-30 G12 Fiberglass Carbon Fiber 5

Nose Cone Ratio Shape Weight Size Apogee Cd Cost Total Weight 10% 10% 10% 5% 28% 27% 10% 100% MC Ogive 3:1 w/ tip 1 4 3.6 5 3.9 4.9 1 3.625 MC Ogive 4:1 w/tip 4.7 4 2.7 3.2 2.2 5 1 3.366 PM Ogive 4:1 w/o tip 4.7 4 5 3.2 5 1.5 4.3 3.765 MC Ogive 5:1 w/o tip 4.8 4 4.2 1.8 4.9 1.3 5 3.613 AR Ogive 5:1 w/o tip 4.8 4 4.1 1.8 4.9 1.3 3.8 3.483 6

Nose Cone Top Choices 3) Madcow 5:1 Ogive 1.Public Missiles 4:1 Ogive 2) Madcow 3:1 Ogive w/ AL tip Apogee = 6080.7’ Apogee = 5881.7’ Apogee = 5978.5’ • • • Drag Coefficient = 1.271 Drag Coefficient = 0.535 Drag Coefficient = 1.3019 • • • Weight = 28 oz Weight = 46.7 oz Weight = 36 oz • • • 7

Fin Planform Trade Study Fin Planform Stability Coefficient of Strength drag Trapezoidal 8 8 8 Elliptical 8 5 9 Clipped Delta 9 8 6 8

Fin Cross Section Trade Study Cross C D (avg) C L (avg) C L /C D (avg) Manuf. Cost Section Ease Rectangular 0.019 0.110 5.583 1 1 Rounded 0.008 0.056 6.588 5 2 Bevel 0.011 0.082 9.252 3 3 Airfoil 0.013 0.096 9.676 10 10 ANSYS Mesh Fin Cross Sections 9

Leading Fin Design Four fins • Trapezoidal planform • 40 degree bevel cross section • G10 Fiberglass • 3/16” Thick • Fin flutter • Flutter velocity - 2909 ft/s • Max velocity - 396 ft/s • 10

Motor Retention System Motor Retainer Cap and Base Thrust Plate Bought In House Bought In House Component $55.56 $100 - $65.05 $24.93 - 8”x8”x1.5” 8”x8”x0.5” Price 6061-T651 Al 6061-T651 Al Easy Feasible Easy Easy Mechanical (3 axis CNC (3 axis CNC Feasibility mill) mill) Thrust Plate Motor Retainer 11

Table of Contents 1. Vehicle Overview ……………………………………………………………………………………………… 2 2. Apogee Targeting System ………………………………………………………………………………. 12 3. Recovery Subsystem ………………………………………………………………………………………... 19 4. Mission Performance Predictions ……………................................................................ 29 5. Payload Overview ……………………………………................................................................. 37 6. Requirements Compliance Plan ………………................................................................. 45 7. Logistics …………………………………………………………………………………………………………….. 49 12

Apogee Targeting System Prediction and Control Design • ATS Electronics Bay Design • Flap Design • Flap Actuation System • 13

Prediction and Control Overview - R denotes target apogee - X(v) denotes current state of the rocket - X p (v-dv) denotes prediction of X(v) 14

Prediction and Control Response 15

ATS Electronics Bay Pi Control ● Raspberry Pi, motor driver, motor (stepper ○ or servo), battery (7.4V LiPo) Modular Control ● shares central controller, battery modules, ○ and coprocessor, and IMU’s with payload deployment 16

Flap Design Solid Rectangular Fin: Pin Flap: Gridded Rectangular Fin: Highest drag force in Rated to hold ~20 Comparable drag to solid ● ● ● subsonic region lbs of drag force fins in subsonic region ● Rated to hold +30lb of ● Least drag force in ● Rated to hold +30 lbs of drag force subsonic region drag force 17

Flap Actuation Central turnpiece extends and retracts flaps through pin joint arms ● Supports and guides for flaps epoxied to bulkhead (attached to rocket shell) ● Coated with teflon tape to reduce friction ○ Bulkhead, arms, central turnpiece all made of aluminum (CNC routed) ● 18

Table of Contents 1. Vehicle Overview ……………………………………………………………………………………………… 2 2. Apogee Targeting System …………………………………………………………………………………. 12 3. Recovery Subsystem ……………………………………………………………………………………... 19 4. Mission Performance Predictions ……………................................................................ 29 5. Payload Overview ……………………………………................................................................. 37 6. Requirements Compliance Plan ………………................................................................. 45 7. Logistics …………………………………………………………………………………………………………….. 49 19

Recovery Subsystem 20

Recovery Bay • Dimensions • Length: 5” • Mass: 21 oz • Key Features • 3D printed battery case and cover • Rotary switch standoffs • Bulkhead-like sled • Coupler coated in aluminum tape for RF shielding • Benefits over Additive Aerospace Sled • More compact • More adaptable • Better wire management 21

Batteries and Switches Cases Battery Case Switch Case • 3D printed • 3D printed • Attaches to bulkhead by screws • Attaches to bulkhead by screws • A sure secure fit • Wires protrude through holes in the side and • Allows for the reuse of rotary switches battery clips go on through holes in the front • Easy to manufacture and assemble • Easily assembled and reusable • Easy to manufacture • Will fit on virtually any sled design 22

Altimeters Altimeter Price Dimensions Weight Altitude Operating Accuracy Voltage PerfectFlite $58.80 0.38 oz ± 0.1% 9V nominal (4V 2"L, 0.85"W, 0.5"H Stratologger CF to 16V) Missile Works $44.95 0.35 oz Not given 9V(3.5VDC- 2.28"L, 0.925"W, ~0.5"H RRC2+ 10VDC) Missile Works $79.95 0. 59 oz Not given 9V(3.5VDC- 3.92"L, 0.925"W, 0.563"H RRC3 10VDC) 23

GPS • Location • Fixed to middle airframe, below the recovery bay • Provide easy access to turn on while on launch pad • Components • 3D printed custom housing module • Eggfinder Tracking System • OpenLog data logger • Power Stick • LiPo battery pack 24

Electronics Wiring • Two redundant systems • Each have own battery • Each have own switch • Drogue charges • Primary: Apogee +1s • Backup: Apogee + 2s • Main charges • Primary: 550 ft • Backup: 500 ft 25

Main Parachute Options SkyAngle CERT-3 XXL Fruity Chute Iris Ultra 84” RocketMan 14 ft • • Canopy with panels Toroidal Canopy with panels • • • High Cd High Cd Moderate Cd • • • Large packing volume Small packing volume High packing volume • • • Moderately expensive Very Expensive Inexpensive • 26