1. 3D-Printed Hybrid Rocket Fuel Grains
Fused Layer ABS Rocketry Experiment
(F.L.A.R.E)
Amy Besio
Jonathan Benson
Richard Horta
John Seligson
Josh Rou
Faculty/Technical
Advisor:
Justin Karl, Ph.D.

2. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design 1
• Mission Statement
• To design, fabricate, and test 3D-printed fuel
grains to optimize hybrid rocket performance
characteristics
• Hybrid Rockets
• Safer
• Non-toxic/non-explosive
propellants
• Command shutdown and
throttling capabilities
• Ease of transport, storage,
and handling
Design Objectives
Liquid
Oxidizer
Igniter
Injector
Solid Fuel
Grain
Nozzle

3. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design 2
Ground Test Article

4. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Josh Rou – Oxidizer Feed System 3
Design Problem
• Hybrid Rocket Disadvantages
• Lower performance
• Low regression rate
• Mass Flow Rate
• Oxidizer
• Valve Size Dependent
• Fuel
• Surface Area Dependent
• Complex Thrust Profile
• Needs Complex Grain Geometries

5. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Josh Rou – Oxidizer Feed System 4
Our Solution
• Optimize exposure of fuel grain
surface area through 3D printing
• Advantages of 3D printing
• Precision
• Relatively Inexpensive
• Readily Available
• Comparable performance
characteristics to HTPB

6. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Josh Rou – Oxidizer Feed System 5
Three Parallel Development Projects
• Test Stand
• Ground Test Article
• Flight Vehicle - End Goal

7. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Richard Horta – Test Stand Design 6
Testing System
• Preliminary Design Requirements
• Factor of Safety = 5
• Cost Effectiveness
• Ease of Maintenance
• Portability
• Compatibility
• Previous Designs

8. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Richard Horta – Test Stand Design 7
Testing System
• Rails Angled 45 Degrees
• Superstrut Platform and Clamps
• Fabrication
• Cutting, Grinding, Deburring
• Milling
• Drilling
• Welding
• Coating

9. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Jonathan Benson – Data Acquisition 8
• Instrumentation Integration
• Button Load Cell
• 12 Volt Excitation
• Pressure Transducers
• 5 Volt Excitation
• External Instrument
• IR Meter
Testing System

10. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Jonathan Benson – Data Acquisition 9
Testing System - Results & Performance
• Pressure Experienced in Testing
• Oxidizer Pressure 4480 kPa
• Combustion Chamber Pressure
4000 kPa
• Temperature Experienced in Testing
• 578 Kelvin
• Force Experienced in Testing
• 1500 Newtons
• Test Stand Performance

11. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design 10
Ground Test Article
• Design Requirements
• Oxidizer/Fuel
• N2O/ABS
• ID: 54 mm
• Force: 500-1000 N
• Chamber Pressure: 3.45 MPa
• Factor of Safety: 2x
• Design Outputs
• Thrust
• Mass Flow Rate
• Chamber Pressure
• Exit Temperature

12. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design
Ground Test Article
• Design Considerations
• Thermochemical Evaluation
• N2O/ABS
• 7.8:1
• Combustion Temperature: 3500 K
• Combustion Chamber
• 6061-T6 Aluminum
• 54 mm X 160 mm
• Nozzle
• Ideally expanded
• Pe=Pa
𝐴 𝑡
=
𝑚 𝑝
𝑃𝑡
𝑅 ∗ 𝑇𝑡
𝑘
= 95 𝑚𝑚2
𝑀𝑒 =
2
𝑘 − 1
∗
𝑃𝑐
𝑃𝑎
𝑘−1
2
− 1 = 2.96
𝐴 𝑒 =
𝐴 𝑡
𝑀𝑒
1 +
𝑘 − 1
2
𝑀𝑒
2
𝑘 + 1
2
𝑘+1
2 𝑘−1
= 490 𝑚𝑚2
𝑉𝑒 =
2𝑘
𝑘−1
∗ 𝑅 ∗ 𝑇𝑐 ∗ 1 −
𝑃𝑒
𝑃𝑐
𝑘−1
𝑘
𝐹 = 𝑚 𝑝 𝑉𝑒 + 𝑃𝑒 − 𝑃𝑎 𝐴 𝑒
11

13. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design
Ground Test Article
• Expected Performance
• Mass Flow Rate
• 0.282 kg/s
• Force
• 670 N
• Specific Impulse
• 194 seconds
• Regression Rate
12

14. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design
Ground Test Article - Testing
Test 1: Live Fire Sequencing
(subsonic)
Test 2: Solid Fuel Pressure
Test
13

15. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design
Ground Test Article - Testing
14

16. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design
Rocket
-100
0
100
200
300
400
500
0 1 2 3 4 5
Force(N)
Time (s)
Thrust- Comparison
90% Infill 25% Infill
90% 25%
Mass Flow
Rate
155 g/s 152 g/s
Thrust 405 N 422 N
Combustion
Pressure
3.9 MPa 3.9 MPa
15

17. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
John Seligson – Data Acquisition
Flight Ready Model
• Type of Motor - Contrial J-245
• 2000m Expected Altitude
• 644 Ns Total Impulse
• 3 s Burn Time
• Flight Mechanics Design
Considerations
• Fins - CP Aft of CG
• Nose Cone - Rounded Curve
• Testing of Remaining Fuel Grains
• 90% Infill
• 25% Infill
• Variable Infill
[Peterson]
16

18. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
John Seligson – Data Acquisition
Flight Ready Vehicle
• Measurements/Control
• Altimetry
• Positioning
• Orientation
• Temperature
• Visual Recording
Component Make Model
Microcontroller PJRC Teensy++ 2.0
SD Adapter PJRC SD Adapter
Altimeter adafruit BMP180
GPS adafruit GPS Breakout
Gyroscope adafruit LSM9DSO
Thermocouple adafruit Type-K Glass Braid
Camera GoPro Hero
17

19. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Jonathan Benson – Data Acquisition
Recommendations
• Development
• Infill of 3D printers
• Different 3D printed Materials
• Nylon
• Polycarbonate
• Different Oxidizers
• Liquid Oxygen
• Design
• New Geometries
18

20. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design 19
Budget
System Previous Current
Test Stand Structure $450.00 $100.00
Data Acquisition Equipment $500.00 $200.00
Rocket Components $650.00 $425.00
Propellant $200.00 $605.00
Total $1800.00 $1330.00

21. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Amy Besio – Project Manager/Propulsion System Design
Acknowledgements
20

22. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Questions?
21

23. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Test Stand Assembly

24. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Test Stand Assembly

25. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Oxidizer Feed System

26. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Oxidizer Feed System

27. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Oxidizer Feed System
Pressure Relief Valves Solenoid Valves

28. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Oxidizer Feed System
Trial
Number
Scale
Precision
(g)
Solenoid Valve
Orifice Diameter
(cm)
∆Mass
(g)
∆Time
(seconds)
Mass
Flow Rate
(g/s)
Component
Removed
Component
Added
Trial 1 50 0.196 100 2.27 44 - -
Trial 2 50 0.196 300 5.33 56 CV -
Trial 3 50 0.196 300 4.99 60 CV, Tubing, ⅛”
Right-Angle
Adapters
-
Trial 4 2 0.196 276 5.24 52.67 CV -
Trial 5 2 0.196 108 1.94 55.67 CV -
Trial 6 2 0.196 102 1.85 55.14 CV -
Trial 7 2 0.635 464 1.93 240.41 CV Large SV, (2)
¼”Tee Adapters
Trial 8 2 0.635 424 1.91 221.99 CV Large SV, (2)
¼”Tee Adapters

29. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Thermal Imaging

30. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Data Acquisition

31. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Data Acquisition

32. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Data Acquisition

33. University of Central Florida-Senior Design Fall 2015
3D Printed Hybrid Rocket Fuel Grains
Alternate Slide - Data Acquisition