Critical Design Review

1
University of North Dakota Frozen Fury

• Critical Design Review
• February 2, 2015

2
General Vehicle Dimensions
Center of Gravity 57.579 inches Center of
Pressure 68.434 Safety Margin 1.76

• Length 105 inches
• Diameter 6.155 inches
• Mass 26.2 lbs

3
Critical Flight and Payload Systems
Different subsystems of the rocket
4
Materials and Justifications

• Airframe carbon fiber
• Superior strength to weight ratio
• Ease of workability
• Fins birch plywood in carbon fiber
• Combines the strength of both materials for a
  more rigid, strong, and lightweight fin
• Bulk-Head/Centering ring 0.5 inch birch plywood
• Cabinet quality grain, few knots, and locally
  available

5
General Vehicle Dimensions
Location of Launch Lugs (inches)
Fin Dimensions (mm)
Location of Centering Rings (inches)
6
Materials and Justifications

• Fins
• Symmetric shape and quantity allows for ease of
  construction, trapezoidal shape limits potential
  damage to fins upon landing
• Diameter
• 6 diameter allows for ease of assembly and
  plenty of workspace.
• Also allows for better utilization of scrap
  components, and expansion of internal components
  if necessary

7
General Vehicle Dimensions
Nose Cone Dimensions (mm)
8
Materials and Justifications

• Nosecone
• Will be purchased to insure proper functionality
• West Systems Epoxy
• Used to bind the above materials together as well
  as some hardware (bolts, nuts, threaded rods)

9
Parachute Attachment Bulkhead
Bulkhead Dimensions (inch)
10
Parachutes
Parachute type Parachute size Harness Type Harness Length Descent Rate
Drogue 36 in ripstop nylon 5ft 62 ft/s
Main 115 in ripstop nylon 5ft 16.08 ft/s
Payload 58 in ripstop nylon 5ft 22.47 ft/s
11
Deployment of Parachutes
12
Flight Analysis
Total motion vs. Time
13
Drift Analysis at 5 mph
14
Drift Analysis at 10 mph
15
Drift Analysis at 15 mph
16
Drift Analysis 20 mph
17
Drag Analysis
Drag Coefficient at 5 mph
18
AGSE Design
ElectricalBox
Ignition Insertion System
Linear Actuator
Payload System
Rocket in Horizontal Position
19
Lifted Rocket Position
Rocket in 5 to vertical Position
20
Frame

• Square Tube Iron

21
Electrical Box
Basic electrical schematic
Arduino board
All components for the AGSE will be housed in the
black box that is on the frame.
22
Claw With Pan/Tilt Bracket

• Servo to open and close claw
• Another servo to tilt claw

Claw assembly (in)
Claw assembled by the team
23
Belt/Slider Rail
Slider with belt assembly (in)
24
Payload Acquisition System
Payload acquisition assembly (in)
25
Belt/Slider Rail
Slider assembled by the team
26
Actuator Position
Rocket actuator assembly (in)

• Linear actuator has stall torque of 240 lbs.

27
Ignition Insertion System
Side view of the ignition system
28
Wire Funnel

• Mounted to the rail
• Will help guide the ignition wire into the rocket
  motor

Ignition system funnel (in)
29
Wire Extension Assembly

• 1, 16 tooth gear is driven by 51 RPM motor
• 2, 32 tooth gears spin rubber wheels
• Steel housing
• Will be mounted on rail

Ignition system gearbox (in)
30
Wire Spool Housing

• Steel housing for spool
• Ignition wire is coiled around spool
• Mounted to rail

Ignition system wire spool (in)
31
Final Design Changes to be Made

• If the stability of the rocket on the rail
  becomes an issue, there will be guides added to
  the rail.
• A counter weight will be added to the end of the
  rail behind the wire spool to alleviate motor
  stress of the actuator.

32
Design Justifications
33
Baseline Motor Selection and Justification
Manufacturer AeroTech
Mfr. Designation K480W
Motor Type reload
Diameter 54.0 mm
Length 57.9 cm
Total Weight 2078 g
Average Thrust 528.67 N
Maximum Thrust 1017.8 N
Total impulse 2273.3 Ns
Burn Time 4.3s

• Justifications
• 54.0 mm diameter allows for easy downscaling
• Black Max Propellant provides the high visibility
  tracking of dense black exhaust

34
Motor Selection Aerotech K480W
Aerotech K480W Thrust per second
35
Thrust-to-Weight Ratio
Thrust to weight ratio 7.751
36
Avionics

• Dual deployment system
• Two Perfect Flight altimeters used as a backup
  system
• Measures barometric pressure
• Mach delay for safety
• Deploys drogue parachute at apogee
• Deploys main parachute at 3000 ft AGL and
  payload parachute at 1000ft AGL

37
Avionics Altimeter Bay
38
Altimeter Bay Schematics
39
Payload Securing
Payload Compartment 3-D View
Payload Compartment Rear View
40
Sequence Code
41
Sequence Code
42
Code
Declaration of Switches and Pins
43
Sequence Code
Initialization of Switches and Pins
44
Code
Starting Positions
Declaration of Switches and Pins
45
Code
Claw Actions
46
Code
More Claw Actions
47
Code
AGSE Actions
48
Code
AGSE Actions
49
Success Criteria for AGSE

• Payload acquisition
• Payload is in the launch vehicle and secured
• Rocket Erection
• Rocket is lifted to a position of 85 degrees from
  the horizontal
• Wire Insertion
• Wire is fully inserted in motor and no accidental
  charge ignites motor

50
Success Criteria for Launch Vehicle

• Rocket launch
• Reaching an altitude of 3000 feet at apogee.
• Rocket recovery
• The recovery system deploying properly at the
  appropriate altitude and recovering the rocket on
  the ground such that it is deemed reusable for
  future launches
• Payload
• The payload should be ejected from the rocket at
  1,000 feet and return to the ground with its own
  parachute.

51
Rocket Flight Stability in Static Margin Diagram

• The center of gravity is forward of the center of
  pressure (closer to the nosecone)

Rocket Flight Static Margin 10.855 Center of
Pressure 68.434 in Center of Gravity 57.579 in
Kinetic Energy ft-lbs
Drogue 1562.95
Main Parachute 68.17
Payload Parachute 70.29
52
Vehicle Safety

• The minimum rod speed that ensures a stable
  flight is generally between 30 fps (20 mph) to 45
  fps (30 mph).
• Exit rail velocity 69.5 ft/s
• A pair of rail beads will be used to ensure the
  rocket reaches adequate speed off of the rail
  while maintaining proper orientation

53
Plan for Vehicle Safety Verification and Testing
Critique Score 1/5 1 Bad 5 Good Comments
Is this design safe? 4 This design will allow for ease of construction and eliminate safety concerns associated with more complex construction methods
Is this design limiting? 4 Altitude is expected to be reached and the design will accommodate larger motors and payload components
Does this design meet the requirements of the payload/rocket? 4 This current rocket design satisfies the requirements for the projected payload.
Will this design land safely? Parachute sizes, impact absorbing design? 4 The current size rocket and parachutes have the rocket descending rapidly under drogue, but slowing to under 25 ft/s under main.
Does this design maximize performance? 3 The rocket has been designed to accommodate the payload as well as larger motors as the design is refined.
Are the materials selected the best for this scenario? 4 Carbon fiber is a strong yet lightweight material that we have had success with in years prior. Past experience with phenolic tubing has yielded structural failure.
Any additional comments? ------- Conduct additional tests and review plan to ensure continued safety
54
Educational Engagement

• Physics Day at UND - November 12, 2014
• This is a program for local middle school to high
  school students to learn about the many different
  facets of physics.
• Gave a presentation about rocketry
• Introduced them to the USLI program and shared
  our past history with the competition
• 200 students attended

55
Educational Engagement

• Outreach at Grand Forks area middle school
• Our team is still in the process of scheduling a
  date to visit the local middle schools.
• Give a brief lecture about rocketry
• We will build and launch balloon rockets
• Have a Q A session about rocketry
• Expect to reach about 30-80 students.

56
Educational Engagement

• UND Physics and Astronomy Talk -February 23rd.
• In an hour long talk, we will detail rocketry
  throughout the ages and hold a demonstration of
  our current AGSE. The average attendance for
  these talks is 30-50 students and other
  interested parties.

57
Vehicle Testing

• Two sub-scale launches were performed to verify
  the recovery system and the main design (fins,
  nosecone).
• There were minor complications in each of the
  launches.

58
Scale Launches

• Length ratio of subscale I
• 11.75
• Length ratio of subscale II
• 11.4
• Fins ratio
• 12.25
• Diameter ratio
• 12

59
Motor and parachutes

• Aerotech 1211W-M
• Total Impulse 460 N/s
• Motor Diameter 1.5 in
• Motor Length 9.82 in
• Parachutes
• Drogue 30 inches
• Main parachute 28 inches
• Payload Parachute 36 inches

60
Subscale Launch I

• Rocket
• Length 60.875 inches
• Diameter 3 inches
• Mass with motors 28.2 ounces
• Stability Margin 1.3

61
Subscale Launch I Simulation
Apogee 2815 ft Maximum velocity 930 ft/s
62
Subscale Launch I Flight
Apogee 2811 ft.
Deployment of Time (s) Altitude (ft) Velocity (mph)
Drogue 13.65 2804 15
Main parachutes 71.90 600 35
63
Flight I Complications

• Lack of space
• Increased charge
• Weakened bond

64
Subscale Launch II

• Rocket
• Length 73.75 inches
• Diameter 3 inches
• Mass with motors 31.9 ounces
• Stability Margin 2.37

65
Subscale Launch II Simulation
Apogee 2801 ft Maximum velocity 881 ft/s
66
Subscale Launch II Flight
Apogee 2621 ft.
Deployment of Time (s) Altitude (ft) Velocity (mph)
Drogue 13.6 2619 18
Main parachutes 62.05 600 35
67
Flight II Complications

• Obstruction when preparing break pins holes
• Slight wobble during launch
• Parachute Complications

68
Near-Future Work

• In the coming weeks, the team will be working on
• For the AGSE Cutting the frame and welding
  it Building of Ignition and lifting
  system Finishing the payload acquisition
  system Positioning of the different
  switches Implementing the electrical system
• For the rocket Ordering of the rocket cylinders
  Building of the Fins Building of the Payload
  securing

69
Questions?