Team 18: Design Optimization of a Supersonic Nozzle
Marc Linares
Alessandro Ciampitti
Marco Robaina
Project Coordinator
Optimization Engineer
CFD Engineer
Advisor: Prof. George S. Dulikravich
Design Optimization of a Supersonic Nozzle
M<1
M=1
M>1
http://www.colorado.edu/MCEN/cmes/czajkowski/gallery/slender_0.075_density.png
De Laval nozzle
Convergent Section
Throat
Divergent Section
Timeline for Presentation
• Problem Statement
• Applications
• Optimization Goals
• Design Considerations
• Software Methods
• Manufacturing
• Validation
• Project Timeline
• Conclusion
Problem Statement
➢Non-uniformities of the flow at the nozzle exit due to upstream
conditions & gradients
o
Pressure
o
Temperature
o
Density
o
Speed
➢Shock wave development inside nozzle
o
Difference of inlet stagnation pressure and exit pressure
Applications
Rocket Propulsion
http://tfm.usc.edu/uploads/articles/6711/img_6347_sp12_b-crop__full.jpg
Wind Tunnel
http://www.coe.montana.edu/me/faculty/george/The%20SWT%20story_rev01_files/image006.jpg
Motivation
➢ Supersonic wind tunnel test facilities improvements
➢ Optimized nozzle shape can maximize thrust force
➢Ø
Global Approach
➢ Many countries are developing space programs
➢ Optimized nozzle will have minimum length & weight
Optimization Goals
Minimize
Flow
Separation
Avoid Shock
Wave
Development
Back Flow
Divergent
Section Length
Weight
Cost
Maximize
Exit Mach
Number
Exit Velocity
Thrust Force
Exit Flow
Uniformity
Exit-to-Throat
Area Ratio
Design Considerations
• 2-D/3-D flow
• Isentropic Quasi-One dimensional
• Euler equations
 non-viscous flow
• Navier-Stokes equations
 viscous turbulent flow
• Chemical properties are not considered
• Shock wave location
• Compressible flow
• Nozzle selection (feasibility)
thttp://www.jacobsrocketry.com/general/graphics/de_leval.JPG
Design Alternative 1: Conical
• Simple Design (feasibility)
• Manufacturing
• Simulation
• Optimization
http://www.tecaeromex.com/imagenes/tobera3.jpg
• Constant half angle at divergent section
• Velocity components in flow
http://www.braeunig.us/space/pics/fig1-04.gif
Design Alternative 2: Bell
• Most commonly used design
• Parabolic cone shape
• Half angle constantly changes
• Shorter length
http://cs.astrium.eads.net/sp/launcher-propulsion/manufacturing/images/ht-vulcain.jpg bell nozzle
• Efficient at design exit pressure
http://www.braeunig.us/space/pics/fig1-05.gif
Design Alternative 3: Dual Bell
• Most difficult design of the three
• Altitude compensation (Ambient Pressure)
• Higher pressure: Wall inflection separates flow
• Lower pressure: Flow through entire geometry
• Higher overall efficiency for changes in pressure
• Lower efficiency at optimal pressure
http://www.kspc.jaxa.jp/japanese/image/reserch/fun_03.jpg
Software Modules Involved
Geometric
Shape & Grid
Response
Surface &
Optimization
CFD Analysis
Modeling
● SolidWorks/ANSYS
○ Initial Designs (from previous
work/designs)
○ Final Design (from optimization)
CFD Analysis
● LOCI
○ 2-D/3-D flow analysis
○ Hot flow/cold flow
http://flowsquare.com/wp-content/uploads/2013/12/Laval_Mach_04k.png
Optimization Process
● ModeFrontier
○ Optimization of nozzle parameters
● Response Surface
● Evolutionary Based Algorithm
○ Particle Swarm (PS)
● Optimal Solution
Manufacturing
• Dimensional Analysis (small scale)
• True scale versus model
• Plexiglas design
• Alternative Materials being considered
Relevant Standards
• AS 9100 Quality management of aerospace industry
• Created by SAE
– Society of Automotive Engineers
• ASME Y14.5
• Many standards are proprietary
http://spaceflight.nasa.gov/gallery/images/station/crew-10/html/jsc2004e45198.html
Validation
• Cold flow testing to be conducted with a compressed air cylinder
• Measuring devices:
• Thermocouples
• Pressure gauge
http://www.harborfreight.com/media/catalog/product/cache/1/image/9df78eab33525d08d6e5fb8d27136e95/i/m/image_23181.jpg
Project Timeline & Responsibilities
Summary: 8 Month Capstone Project
 Develop a system for better performing supersonic nozzles
 Maximizing
• Mach Number & Flow Uniformity
 Minimizing
• Divergent Length & Flow Separation
 Use of different software programs
 Analysis & Optimization
 Manufacturing & Testing
 Standards
 Cold gas