Transcript Document

University of
North Dakota
Frozen Fury
Critical Design Review
February 2, 2015
General Vehicle Dimensions
Length: 105 inches
Diameter: 6.155 inches
Mass: 26.2 lbs
Center of Gravity: 57.579 inches
Center of Pressure: 68.434
Safety Margin: 1.76
Critical Flight and Payload Systems
Different subsystems of the rocket
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
General Vehicle Dimensions
Location of Launch Lugs (inches)
Location of Centering Rings (inches)
Fin Dimensions (mm)
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
General Vehicle Dimensions
Nose Cone Dimensions (mm)
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)
Parachute Attachment Bulkhead
Bulkhead Dimensions (inch)
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
Deployment of Parachutes
Flight Analysis
Total motion vs. Time
Drift Analysis at 5 mph
Drift Analysis at 10 mph
Drift Analysis at 15 mph
Drift Analysis 20 mph
Drag Analysis
Drag Coefficient at 5 mph
AGSE Design
Electrical
Box
Ignition
Insertion
System
Linear
Actuator
Payload
System
Rocket in Horizontal Position
Lifted Rocket Position
Rocket in 5° to vertical Position
Frame
Square Tube Iron
Electrical Box
Basic electrical schematic
Arduino board
All components for the AGSE will be housed in the
black box that is on the frame.
Claw With Pan/Tilt Bracket
● Servo to open and close
claw
● Another servo to tilt claw
Claw assembly (in)
Claw assembled by the team
Belt/Slider Rail
Slider with belt assembly (in)
Payload Acquisition System
Payload acquisition assembly (in)
Belt/Slider Rail
Slider assembled by the team
Actuator Position
Rocket actuator assembly (in)
● Linear actuator has stall torque of 240 lbs.
Ignition Insertion System
Side view of the ignition system
Wire Funnel
● Mounted to the rail
● Will help guide the
ignition wire into the
rocket motor
Ignition system funnel (in)
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)
Wire Spool Housing
● Steel housing for
spool
● Ignition wire is coiled
around spool
● Mounted to rail
Ignition system wire spool (in)
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.
Design Justifications
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
Motor Selection: Aerotech K480W
Aerotech K480W Thrust per second
Thrust-to-Weight Ratio
Thrust to weight ratio 7.75:1
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
Avionics: Altimeter Bay
Altimeter Bay Schematics
Payload Securing
Payload Compartment 3-D View
Payload Compartment Rear View
Sequence Code
Sequence Code
Code
Declaration of Switches and Pins
Sequence Code
Initialization of Switches and Pins
Code
Starting Positions
Declaration of Switches and Pins
Code
Claw Actions
Code
More Claw Actions
Code
AGSE Actions
Code
AGSE Actions
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
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.
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
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
Plan for Vehicle Safety
Verification and Testing
Critique
Score
1/5
Comments
1 = Bad
5 = Good
Is this design safe?
4
This design will allow for ease of construction and
eliminate safety concerns associated with more
complex construction methods
Altitude is expected to be reached and the design will
accommodate larger motors and payload components
This current rocket design satisfies the requirements for
the projected payload.
Is this design limiting?
4
Does this design meet
the requirements of the
payload/rocket?
4
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
Are the materials
selected the best for this
scenario?
Any additional
comments?
4
The rocket has been designed to accommodate the
payload as well as larger motors as the design is
refined.
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.
Conduct additional tests and review plan to ensure
continued safety
-------
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
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.
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.
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.
Scale Launches
Length ratio of subscale I:
1:1.75
Length ratio of subscale II :
1:1.4
Fins ratio:
1:2.25
Diameter ratio:
1:2
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
Subscale Launch I
Rocket:
● Length: 60.875 inches
● Diameter: 3 inches
● Mass with motors: 28.2 ounces
● Stability Margin: 1.3
Subscale Launch I Simulation
Apogee: 2815 ft
930 ft/s
Maximum velocity:
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
Flight I Complications
● Lack of space
● Increased charge
● Weakened bond
Subscale Launch II
Rocket:
● Length: 73.75 inches
● Diameter: 3 inches
● Mass with motors: 31.9 ounces
● Stability Margin: 2.37
Subscale Launch II Simulation
Apogee: 2801 ft
881 ft/s
Maximum velocity:
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
Flight II Complications
● Obstruction when preparing break pin’s holes
● Slight wobble during launch
● Parachute Complications
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
Questions?