Post on 11-Feb-2017
transcript
Solid Motor Casing & Design
Solid Design Team:
Tony, Jason, Andrew, Tarique, Esteban, Jack 1
Quick Recap
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Motor and Propellant Selection● Non-Toxic
● Non-Detonable
● HTPB/AP/AL Composite
Aerotech L2200G-P Mojave Green
Design Process
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● Payload
● Drogue Chute
● Payload/Avionics
● Main Chute
● Motor and Casing
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What we know:● Peak Thrust ≈ 3100N
● Burn Duration ≈ 2.4s
● Dimensions
What we need to know:● Chamber Pressure
● Chamber Temperature
Motor Case Design Considerations
(in)
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What we know:● Peak Thrust ≈ 3100N
● Burn Duration ≈ 2.4s
● Dimensions
What we need to know:● Chamber Pressure
● Gas Exit Velocity
● Gas Exit Temperature
Nozzle Design Considerations
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What we know:● Motor Overall Performance
What we need to know:● Nothing
Igniter Considerations
Solid Rocket Motor
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● Case
● Solid Propellant
● Igniter
● Nozzle
Motor Case Loadings/Stresses
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(1)
Motor Case Materials● Composite
o E-glass
o Aramid (Kevlar 49)
o Carbon fiber
● Metalo Titanium alloy
o Alloy steel
o Aluminum alloy 2024
● Combination
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(1)
Composites
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(3)
Filament Winding
● Orientation of Filament
o Compromise
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(1)
12(1)
Metals
● Titanium alloyo Heavy
o Good strength to weight ratio
● Alloy steelo Heavier
o Strongest
● Aluminumo Provides good strength to weight ratio
o Lightest13
14(1)
Nozzles
There are five types
● Fixed (a)
● Movable (b)
● Submerged (c)
● Extendible (d)
● Blast-Tube-Mounted (e)
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Nozzles: Design and Construction
● Ablatively Cooled
● Steel or aluminum Shells
● Composite ablative liners
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Nozzle Design Decision
WE’RE NOT BUILDING ONE!!
Why?!?
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Nozzle Selection
● Aerotech L2200G-P Mojave Green and RMS
75/5120 kit comes with a nozzle
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Solid Rocket Motor ExpertRobert Watson
Robert at BuyRocketMotors.com
817-494-3834
rwatson@buyrocketmotors.com
www.BuyRocketMotors.com
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Igniters
Pyrogens
Pyrotechnic
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Igniters
Most frequent is Electroexplosive device
(Pyrotechnic)
● Bridgewire
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NASA- Solid Rocket Motor Igniters March 1971 pg. 45
http://electronicpackaging.asmedigitalcollection.asme.org/article.aspx?articleid=1408779
http://electronicpackaging.asmedigitalcollection.asme.org/article.aspx?article
id=1408779
Field Trip?
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Summary● Motor Case: 2024 Aluminum Alloy
o Lightweight
o Capable of enduring thermal and pressure loads
o Machined or Off-The-Shelf (TBD)
● Nozzle: Built into Motoro Saves time and money
o Redundant to build additional nozzle
● Igniter: Bridgewire explosiveo Reliable
o Good “performance”
o Cheap
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Whats Next?
● Propellant Combustion
o Burn rate
o Flame Pattern
o Ignition Characteristics
● Propellant Stability
o Acoustic Resonance
o Ignition Wire Configurations
o Internal Gas Flow Cavity Considerations
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References
(1) Rocket Propulsion Elements, 8th Edition. Sutton, George P. and Biblarz, Oscar.
(2) Solid Rocket Motor Igniters. NASA
(3) Cowles, Devon K. "Design of a Rocket Motor Casing." Diss. Rensselaer Polytechnic Institute, 2012. Print.
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Questions?28