University of Florida CDR Presentation Slide 2 Outline Vehicle
Design Payload Design Recovery System Component Testing Subscale
Flight Simulations Outreach Future Work Slide 3 Vehicle Design Nose
cone and 4 main sections Avionics Bay is fixed inside upper
airframe and Mid Airframe Body diameter is 5.455 Slide 4 Static
Stability Diagram The center of pressure (CP) is located 86 from
the tip of the rocket nose. The center of gravity (CG) is located
78 from the tip of the rocket nose. The maximum diameter of the
rocket is 5.455 . These dimensions result in a static margin of
1.45, which is within the range desired (between 1 and 2). CG CP
Slide 5 Tube Construction All three airframes (upper, mid, and
lower) will be made of phenolic tube wrapped in a composite mixture
of two layers of 4 ounce fiberglass and Aeropoxy. The first body
tube has already been made, as shown below Slide 6 Upper Airframe
45 long, 7.79 lbs. (w/ contents) From bottom: contains top of
avionics bay, payload, payload drogue, rocket drogue, nose cone
insert Slide 7 Avionics Bay 10 long, 2.83 lbs (w/ contents)
Phenolic tube with 0.5 birch ply bulkheads Serves as coupler for
Main Airframe Upper Airframe joint, therefore it does not add
length to the rocket Screws into both of these airframes to prevent
separation Slide 8 Avionics Bay All-thread provides structural
support Easy-to-use thumb nuts to wire igniter outputs and hook up
ejection charges 1/8 G-10 fiberglass serves as platform for
electronics mounting Contains two redundant PerfectFlite Altimeters
(each powered by their own 9-volt battery), a GPS, and a
transceiver (powered by a 9-Volt battery) Slide 9 Mid Airframe 30
long, 3.47 lbs From bottom: contains rocket main parachute and
bottom of avionics bay Slide 10 Lower Airframe 30 Long, 9.07 lbs, 3
Fins From Bottom: Contains 54mm motor mount, three centering rings,
and motor retention Slide 11 Motor Retention Aluminum sleeve with
indention and snap ring groove Motor thrust ring pushes on aluminum
indention instead of phenolic tube Slide 12 Motor Choice The motor
has been changed to the Loki L1400 because of the unavailability of
the AMW L1300 Characteristics of the L1400 Total Impulse: 2850.6 Ns
(175.6 Ns greater than L1300) Peak Thrust: Officially 2710.5 N, but
RockSim reports 1906.4 N, large discrepancy Burn Time: 2.0 s (same
as L1300) Performance w/ Rocket Thrust-to-Weight Ratio: 11.1
Rail-exit-velocity: 72.4 ft/s (with 7 foot rail) Slide 13 L1400
Thrust Curve Source: thrustcurve.org Slide 14 Outline Vehicle
Design Payload Design Recovery System Component Testing Subscale
Flight Simulations Outreach Future Work Slide 15 Payload Housing
and Integration Folds up while inside upper airframe A torsional
and tensional spring in each leg creates a sprawling motion once
payload is deployed Wheels allow easy vertical sliding of payload
Rests in shoes during flight, which are fixed to inside of Upper
Airframe Tube is made out 1/8 T6-6061 Aluminum, with an outside
diameter of 3.25 Legs are made out of 1/16 Aluminum U-Channel
*Note* - video cameras, parachute compartment, and payload lid not
shown in this drawing Slide 16 Payload Electronics Contains two
redundant R-DAS Tiny altimeters that control the payloads main
parachute deployment and record all sensor data. Each R-DAS Tiny
has its own 11.1V flight battery Contains two analog temperature
and two analog humidity sensors Contains a GPS and transceiver
powered by the batteries on their respective boards Similar
structural design as the Avionics Bay Two video cameras attached to
the outside of the payload bay Slide 17 Payload Lid Serves as mount
for UV sensors and solar cells Slide 18 Payload Wiring Schematic
Slide 19 Outline Vehicle Design Payload Design Recovery System
Component Testing Subscale Flight Simulations Outreach Future Work
Slide 20 Recovery Method Rocket Drogue: 36 round Descent Rate: 64
ft/s Rocket Main: 96 round Descent Rate: 21 ft/s Payload Drogue:
Heavy Duty Streamers Descent Rate: Undetermined Payload Main: 36
round Descent Rate: 19 ft/s Two recovery systems because of payload
separation Redundant PerfectFlite altimeters will control the
rockets dual deployment Redundant R-DAS Tiny altimeters will
control the payloads dual deployment The payload will use streamers
as a drogue to prevent shading of the solar and UV sensors 5/8
tubular nylon will connect all sections of both rocket and the
payload to their respective parachutes Slide 21 Outline Vehicle
Design Payload Design Recovery System Component Testing Subscale
Flight Simulations Outreach Future Work Slide 22 Wind Tunnel
Testing Undergraduate low-speed wind tunnel on campus Open-circuit,
max speed of 120 mph Test section: 12x12 cross-section, 24 long
Slide 23 Experiment 1 - Fins With Varied Paint Combinations Fin 1
Control Fin Fin 2 Paint Fin 3 Primer & Paint Fin 4 Primer,
Paint, & Gloss Slide 24 Experiment 2 Fins With Varied Shape
Combinations Fin 1 Control Fin Fin 5 Rounded LE Fin 6 Tapered TE
Fin 7 Rounded LE and Tapered TE Slide 25 Wind Tunnel Results Drag
ReductionApproximate Fin DesignVs. Control Fin (%)Coefficient of
Drag Paint4.39%0.3313 Paint and Primer4.39%0.3313 Paint, Primer,
Gloss2.05%0.394 Rounded Leading Edge (LE)5.26%0.3283 Tapered
Trailing Edge (TE)0%0.3465 Rounded LE, Tapered TE8.48%0.3171
Greatest Reduction in drag from the rounded LE, tapered TE fin The
tapered TE fin showed no drag reduction at all. The fins that were
painted but not glossed showed higher drag reduction that the
glossed fin Drag Coefficient calculation assumptions: There is a
linear relationship between compressor speed and airspeed The
structure holding the fins produced negligible drag in addition to
the fin. For higher accuracy, the drag from the test structure
needs to be accounted for and the speed airspeed needs to be
calibrated properly Slide 26 Recovery System Testing Dual
Deployment Test with PerfectFlite Hooked up Christmas lights as
imitation igniters Placed altimeter inside avionics bay Extracted
air from the tube and both Christmas bulbs lit up after air was
passed back into the tube and air pressure was restored The data
was checked to ensure that the igniters were fired at the correct
altitude Subscale ejection charge testing The first charge needed
to eject the payload at least 15 feet from the rocket without
causing overwhelming stress on any components The second charge
needed to eject the lower airframe at least 15 feet from the rocket
without causing overwhelming stress on any components Three grams
of black powder met the criteria of both charges, and worked
successfully in the subscale test flight Slide 27 Payload Testing
Temperature and humidity sensor testing complete by seeing change
in voltage in varying temperature and humidity climates GPS and
XBEE are now functioning correctly with the software on the ground
after much trial and error Slide 28 Vibrations Testing Evaluate
deformation characteristics during flight Are modal frequencies
within gust spectrum? What mode shapes result from stiffness/mass
distribution? Ground vibration test (GVT) Soft support was bungee
Sine sweep from 10-1500 Hz 2 lb force actuator Impact hammer
Measured vibrations Laser Doppler vibrometer (LDV) Accelerometers
Load cell measured force input Utilized subscale rocket after
launch Slide 29 Vibrations Testing Experimental setup Laser on
structure Actuator and load cell Slide 30 Vibrations Testing Found
variety of mode shapes Similar to 2 beams cantilevered around high
stiffness near avionics bay Mode shapes indicated tip deflections
were not large even with pounds of force No additional stiffness
seems required for flight safety during short portions of flight
with high dynamic pressure Slide 31 Outline Vehicle Design Payload
Design Recovery System Component Testing Subscale Flight
Simulations Outreach Future Work Slide 32 Subscale Flight January 8
th, at NEFAR 18 mph winds, 10 launch angle 88.5 length, 3 diameter,
8.75 pounds The Gorilla I235 motor was used, and the same motor
retention concept for the full scale was used Successful dual
deployment and payload separation, rockets main parachute deployed
at 300 feet to avoid excessive drift Payload contained only a main
parachute that was deployed at apogee, which resulted in excessive
drift of the payload The payload spun at a relatively fast rate
while descending, which could be an issue for our full scale
payload which will need to take quality video and land without
turning over; a swivel bolt has been considered to mitigate this
problem Slide 33 Subscale Static Test Created our own static test
stand Tested the I235 to input into our MATLAB program to simulate
subscale flight We also plan to test our full scale motor Slide 34
Subscale Altitude Results Maximum altitude from the PerfectFlite
was 890 feet The main parachute was deployed at 300, as can be seen
from the graph below The main chute descent rate calculated from
this data was about 20 ft/s, which is in the desired range Slide 35
Outline Vehicle Design Payload Design Recovery System Component
Testing Subscale Flight Simulations Outreach Future Work Slide 36
Flight Simulations Slide 37 MATLAB 2DOF MATLAB has been updated to
include downrange motion of the rocket Downrange motion is only
affected by launch angle; no angle of attack Better reflection of
physical system Still lacks: Winds Parachutes Oscillations
Rotations Slide 38 Drag Coefficient Lack of knowledge of the true
coefficient of drag prevents accurate simulation. True for RockSim
and MATLAB In order to achieve a better estimate of the drag
coefficient, the max altitude of the MATLAB 2DOF was matched to the
max alt. of the subscale launch altimeter data Slide 39 Full Scale
Max Altitude Optimization Ran RockSim model at various wind
conditions with the L1400 Found that, to minimize downrange drift,
the launch angle into the wind should increase by one degree for
every mph of wind Found the additional mass needed to reach a mile
depending on the launch angle On launch day, once launch conditions
are known, the additional mass needed will be added with modeling
clay in between the top two centering rings (near the center of
gravity), then the top centering ring will be screwed in place
Launch Angle ()Wind Condition (mph)Altitude no mass added (ft)Mass
added to achieve mile (oz) 00566826 05566326 010564725 50562023.5
55558921.5 510554518.5 100547914 105542410 53565 1505252 1555178
15105091 Slide 40 Outline Vehicle Design Payload Design Recovery
System Component Testing Subscale Flight Simulations Outreach
Future Work Slide 41 Educational Engagement Presented to 150 5 th
graders at Hidden Oak Elementary School for one hour PowerPoint
presentation taught students about the basics of rocketry, how to
get involved, and how to remain safe Three model rockets were
launched to give the students an first-hand example of rocketry
Slide 42 Educational Engagement Presented to sixty 4 th -8 th
graders at Millhopper Montessori School (private school) for one
hour Similar presentation to the one at Hidden Oak, but the
subscale rocket was also shown Like at Hidden Oak, three model
rockets were launched in a nearby field for the students to see
Slide 43 Educational Engagement Thank you note from Hidden Oak
Student Slide 44 Educational Engagement Engineering-Fair This
department wide event occurs on February 22 nd and 23 rd and brings
in elementary, middle, and high school students from the local area
to teach them about engineering The USLI team plans on sharing a
booth at this fair with AIAA and will teach students the basics of
rocketry and what to do in school to better their chances at
getting into UF Aerospace Day UF AIAA chapter brings together
middle school students from around the local area to build gliders,
bottle rockets, and small model rockets The USLI team will provide
support in model rocket building and launching and will also launch
some higher power rockets to influence the students to pursue
engineering studies. Date is uncertain Slide 45 Industry Presented
to three SpaceX employees Used PowerPoint to describe the work done
over the past two years, and what the team is working towards
Showed the subscale rocket, our static test stand, and the data
from the wind tunnel experiments Also plan to present to Northrop
Grumman representatives in late February Slide 46 Outline Vehicle
Design Payload Design Recovery System Component Testing Subscale
Flight Simulations Outreach Future Work Slide 47 Continue MATLAB
adjustments Parachutes added to modify descent rate improve
downrange displacement estimation MATLAB model will be extended to
3DOF More altimeter data collected from second subscale launch and
full scale rocket launch to adjust coefficient of drag Continued
wind tunnel testing to compare experimental C D values with RockSim
C D values Compare with RockSim for various wind speeds RockSim and
MATLAB models compare to launch data. Best-fit determined Slide 48
Payload Testing Sensor conversion constant verification Solar cell
has range of 430 to 1100 nm. Test the voltage to W/m 2 conversion
constant UV sensor voltage to W/m 2 conversion constant (1.962)
Sensor-to-RDAS configuration R-DAS Tiny altitude testing Will be
tested with second subscale flight and compared with PerfectFlite
altimeter Video camera vibration testing Battery voltage check
Slide 49 Recovery System Testing Full scale ejection charge ground
testing Need parts to be ejected at least 15 feet apart from each
other without significantly damaging components Payload streamer
descent rate verification Need a descent rate between 50 and 100
ft/s Payload bay separation testing Sliding in and out of upper
airframe, legs springing out Payload landing testing At a maximum
allowable velocity of 22 ft/s With horizontal motion, rotation, and
tilt angles R-DAS & GPS testing in Avionics Bay and Payload Bay
Slide 50 Static Motor Testing The L1400 will be tested on a
different test stand provided by our mentor, Jimmy, which is
capable of such large motors This will test our ignition method
This will help verify which motor characteristics that should be
trusted- the official one provided by the NAR or the one provided
by RockSim The motor will also be tested with the retention device
connected, just in case it effects the exhaust flow at all Slide 51
UF Rocket Team Timeline Slide 52 Questions?
