8 March 2014 Basics of Rocketry Brian Katz March 2014 SpaceRocket Curriculum Goals Provide Information About Space Science Rocketry and Transportation Machines Stimulate Interest in SchoolLearningGoalsBetter OnesSelf ID: 419320
Download Presentation The PPT/PDF document "Educator’s Work Shop" is the property of its rightful owner. Permission is granted to download and print the materials on this web site for personal, non-commercial use only, and to display it on your personal computer provided you do not modify the materials and that you retain all copyright notices contained in the materials. By downloading content from our website, you accept the terms of this agreement.
Slide1
Educator’s Work Shop8 March 2014 - Basics of Rocketry
Brian Katz
March 2014Slide2
Space/Rocket Curriculum GoalsProvide Information About Space, Science, Rocketry and Transportation MachinesStimulate Interest in School/Learning/Goals/Better One’s-Self
Promote Open Discussions, Allow Students To Think, Express and Brainstorm
Teach Students How To Follow Instructions and Complete a Project - working together as a team (Build and Possibly Launch a Rocket)Sessions #1: History of Space Travel#2: Orbits and Gravity#3: General Rocketry#4: Rocket Design#5: Build Rocket(s)#6: LaunchSession FormatsImagery (online videos): “Fire and Smoke”Rocket building project and launch (rocket derby)
General OverviewSlide3
GoalFamiliarize Students with the Fascinating History of RocketryTalk about how to accomplish a “big” project – break it down into sub sections and accomplish piece by piece (Mercury/Gemini/Apollo)
See attachment 1:
History of Space Travel Presentation – walk through thisVideos:http://www.youtube.com/watch?v=kEdtvct6Tf0http://www.youtube.com/watch?v=8y3fIr4dVYE&feature=relatedhttp://www.youtube.com/watch?v=awyuMF9rYhQhttp://www.youtube.com/watch?v=CdQFZRJhkCkhttp://www.youtube.com/watch?v=vFwqZ4qAUkE
Side topics/discussions:
Balloons, Airplanes, Helicopters, Rockets – Why/How Do They FlyEmphasize Ingenuity/Motivation to CreateDigress – Find Their Interests, Search For Ideas, What Have they ever built, want to build, etc…Watch October Sky and Apollo 13
Session #1: History Of Space TravelSlide4
Goal:Instruct Students on where we are going – to space, what is space?Discuss Orbit, Gravity and Atmosphere
Orbit:
What is an Orbit: Show Video With Canyon Ball: http://spaceplace.jpl.nasa.gov/en/kids/orbits1.shtmlGravity: a. Talk about how ideally, all masses fall to ground at same acceleration; discuss big rock/little rock when dropped will hit ground at the same time b. Talk about gravity around all planets/moons c. Discuss table of relative body weights on other planets ready
d. Show video of Astronauts In Space Shuttle and explain that they are floating because they are FALLING!! Use dropping elevator scenario or the dropping airplane scenario
Atmosphere:Talk about friction, rub hands together for younger kids
Session #2: Orbit and Gravity
Relative weights of objects on planets
Mercury
0.38
Venus
0.91
Earth
1
Mars
0.38
Jupiter
2.54
Saturn
1.08
Uranus
0.91
Neptune
1.19
Pluto
0.06
Moon
0.6Slide5
GoalInstruct Students on General Rocketry – what are rockets, their uses, their operation principlesBasic Operation
How/Why Rockets Fly – fire/smoke out the backend – equal and opposite reaction, payload upfront, separation of stages – why?
Temperatures/Speeds/MaterialsNewton’s Laws (see next slide)Digress – Talk about science, science laws and our worldSession #3: General Rocketry Slide6
Session #3: General Rocketry Slide7
Session #3: General Rocketry Continued
Newton’s Laws of Motion
1st Law (Inertia):“In the absence of contrary forces, the speed and direction of an object’s movement will remain constant.”Explanation: The force generated by the escaping gasses from the rocket motor must be great enough to lift the rocket’s total mass from the launch pad, or it will not fly. 2nd Law (Acceleration):
“A body that is subject to forces moves at a speed which is proportional to the amount of force applied.”
Explanation: The greater the force supplied by the rocket motor, in relation to the total mass of the rocket vehicle, the faster it will go.3rd Law (Action/Reaction):“For every force action there is an equal and opposite reaction.”Explanation: Release of gases through the nozzle (action) produces a force on the rocket (reaction) in the opposite direction, causing the rocket to accelerate.Slide8
From Newton’s 2nd Law (motion of the Rocket)-Where:
F = force
m = massa = accelerationThe rocket motor’s total energy is called its total “Impulse” and is a measure of rocket motor’s overall performance-Impulse is the sum (or integral) of total force imparted over the time it acts upon the rocket: orWhere:F = force history profileT = Total time
Session #3: General Rocketry Continued Slide9
Goal:
Dig in deep to rocket design - learn the major components and
systemsDiscuss Design, Analysis, Test, BuildDiscussion:Propulsion (Solid, Liquid)Fins – why do we need themNose Cone – Aerodynamics and payload protectionNozzle – essence of the propulsion systemIgniter – gets it all started
Operation
How do we Maneuver RocketsFlight TerminationCountdown/proceduresShow Rockets That Didn’t Make It Videohttp://www.youtube.com/watch?v=13qeX98tAS8What can we learn from this video?
Session #4: Rocket DesignSlide10
Session #4: Rocket Design – Propulsion Systems
By 1926, Goddard had constructed and tested successfully first rocket using liquid fuel on March 16,1926, at Auburn, Massachusetts.
Rocket used cylindrical combustion chamber with impinging jets to mix and atomize liquid oxygen and gasoline
The rocket, which was dubbed "Nell", rose just 41 feet during a 2.5-second flight that ended 184 feet away in a cabbage field
US and German engineers quickly ran with this idea and greatly expanded on the technologySlide11
Session #4: Rocket Design – Propulsion Systems
Liquid
vs
Solid Propulsion SystemsSlide12
Session #4: Rocket Design – Liquid Propulsion Systems
Turbo Machinery
Boost Pumps
Main Pumps
Injector
Igniter
Combustion Chamber
Nozzle
Heat Exchanger
Mixture and throttle Valves
Pneumatic actuation,
pressurant
, and purge systemsSlide13
Session #4: Rocket Design – Liquid Propulsion Systems
Rocket
Equation Variables:
q
= ejected mass flow rate
V
e
= exhaust
gas ejection speed
P
e
= pressure
of the exhaust gases at the nozzle exit
P
a
= pressure
of the ambient atmosphere
A
e
= area
of the nozzle
exit
A
t
=
throat area
of the
nozzle
m
0
= initial
total mass, including
propellant
m
1
= final
total
mass
v
e
= effective exhaust velocity go = Gravitational ConstantPc = Chamber PressureF (ThrustVac) = Force produced by the engine at 100% throttle in a vacuum environmentΔv = maximum change of velocityIsp = Ratio of the thrust to the ejected mass flow rate used as the primary efficiency measureC* (C-Star) = characteristic exhaust velocity term used as a primary engine development valueSlide14
Session #4: Rocket Design – Liquid Propulsion Systems
Major Components
InjectorStructural Jacket
Coolant Liner
Coolant Inlet ManifoldNozzle extension attachmentDesign Considerations
Oxidizer / Fuel Mixing
Ignition
Flame Holding
Cooling
Weight
Manufacturability
Engine Integration
Combustion ChamberSlide15
Session #4: Rocket Design – Liquid Propulsion Systems
Nozzle is
Tightly
Integrated with
Combustion
C
hamber
N
ozzle
can be an awkward part of engine that makes packaging difficult
Extendable Nozzles are complicated and expensive, (Delta 4 and Arianne upper stages are examples)
Fixed nozzles are bulky and extend vehicle length, and increase re-contact risks
Nozzle Cooling is commonly Achieved by
Ablative materials
Regenerative cooling
Film Cooling
NozzleSlide16
Session #4: Rocket Design – Liquid Propulsion Systems
Hypergolic: fuels and oxidizers that ignite spontaneously on contact with each other and require no ignition source
Nitrogen
Tetroxide
(NTO, N2O4). red-fuming nitric acid N2H4 - Hydrazine
UDMH – Unsymmetrical
dimethyl
hydrazine (
Lunar
lander
RCS UDMH/N2O4)
Aerozine
50 (or "50-50"), which is a mixture of 50% UDMH and 50% hydrazine
MMH (CH3(NH)NH2) -
Monomethylhydrazine
NTO/
Aerozine
50 for Delta II second stage
NTO/MMH is used in the Shuttle OMS
http://en.wikipedia.org/wiki/Liquid_rocket_propellants
PropellantsSlide17
Session #4: Rocket Design – Liquid Propulsion Systems
Simplest of the Power Cycles
No turbo-machinery making it one step up in complexity over solid motors
Requires high pressure tank structure to provide sufficient inlet pressures
Common for hypergolic engines which also eliminates the need for an ignition source
Chamber pressures ~100 to 200 psi
AJ-10 uses NTO/A50
ISP
Vac
271 Sec
7.5k lbs thrust
Space X Kestrel uses LOX/RP-1
ISP
Vac
317 Sec
6.9k lbs of thrust
Pressure Fed SystemSlide18
Session #4: Rocket Design – Liquid Propulsion Systems
Engines are commonly tested at ground level, usually in vertical configuration or horizontal configuration with slight slant
Upper stage engines are commonly
testing in altitude chambers
Exhaust gas flow detachment will occur in a grossly over-expanded nozzle.
Thrust
Vac
: 750,000
lbf
(3.3 MN)
Burn Time: 470 s
Design: Gas Generator cycle
Specific impulse: 410 s
Engine weight – dry: 14,762 lb (6696 kg)
Height: 204 in (5.2 m)
Diameter: 96 in (2.43 m)
Overexpanded
Optimum
UnderexpandedSlide19
Session #4: Rocket Design – Liquid Propulsion Systems
Ground systems for liquid
rockets
are commonly more complex than the
rocket
itself
Atlas
V pad has accommodations for LOX, RP, H2, N2, and He
Extensive plumbing, tanking and de-tanking capabilities
Electrical
control
to ensure proper filling and top-off
Significant leak, thermal, flammability, oxygen deficiency and explosive concerns
Day of launch operations are extensive and very dynamic during preparation, fueling, monitoring, top-off, startup verification, liftoff disconnects, and possible shutdown and de-tanking operations
vs
Liquid Propulsion
Solid PropulsionSlide20
Current Large Space Launch Vehicles
Atlas V
Delta IV
Heavy
Delta
II
Falcon
9
Antares
Discuss:
- Vastness of these engineering marvels – as tall as a 10 – 20 story building
- Attention to detail, ask questions, learn, communicate with each other
Slide21
Session #4: Rocket Design – Solid Propulsion Systems
Convert chemical energy to heat ==>> Movement of heated gases ==> Energy of motion
(Burning Propellant) (through Nozzle exit) (Imparted Force)
Cut-away view of a typical Rocket Motor
Propellant
Ignitor
Exhaust Nozzle
Motor Case
Discuss:
- Solid Propellant details
- Concept of ground testing – why?Slide22
Flight ComputerGuidance/Navigation and ControlElectrical PowerThrust Vector Control
RF
Session #4: Rocket Design – Electrical Systems Discuss: - There are lots of different types of engineers who work with rockets – we work as a teamSlide23
Session #4: Rocket Design – Ordnance Systems
Flight Termination
Payload Separation
Stage Separation
Discuss:
- Why Do we need Flight Termination?
- Why Do we need separation mechanisms?Slide24
Goal: Build Rockets/team work/follow instructions – team work
Build Ideas:
Students Read Out loud InstructionsStudents Initial Steps CompleteStudents Perform Quality InspectionsLaunch Ideas:Create Launch Countdown Checklist and Have various students perform dutiesTest ConductorPad ChiefRange Safety OfficerCounter
Session #5 and #6: Rocket Building and Launch