1. Team 18: Design Optimization of a Supersonic Nozzle
Marc Linares
Project Coordinator
Alessandro Ciampitti
Optimization Engineer
Marco Robaina
CFD Engineer
Advisor: Prof. George S. Dulikravich

2. Design Optimization of a Supersonic Nozzle
De Laval nozzle
Convergent Section
Throat
Divergent Section

3. Timeline for Presentation
Problem Statement
Applications
Optimization Goals
Design Considerations
Software Methods
Manufacturing
Validation
Project Timeline
Conclusion

4. Problem Statement
Non-uniformities of the flow at the nozzle exit due to upstream conditions & gradients
Pressure
Temperature
Density
Speed
Shock wave development inside nozzle
Difference of inlet stagnation pressure and exit pressure

5. Applications Rocket Propulsion Wind Tunnel

6. Motivation Global Approach
Supersonic wind tunnel test facilities improvements
Optimized nozzle shape can maximize thrust force Ø
Many countries are developing space programs
Optimized nozzle will have minimum length & weight
Global Approach

7. Optimization Goals

8. Minimize Flow Separation Avoid Shock Wave Development Back Flow
Divergent Section Length
Weight
Cost

9. Exit-to-Throat Area Ratio
Maximize
Exit Mach Number
Exit Velocity
Thrust Force
Exit Flow Uniformity
Exit-to-Throat Area Ratio

10. 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)
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11. Design Alternative 1: Conical
Simple Design (feasibility)
Manufacturing
Simulation
Optimization
Constant half angle at divergent section
Velocity components in flow

12. Design Alternative 2: Bell
Most commonly used design
Parabolic cone shape
Half angle constantly changes
Shorter length
Efficient at design exit pressure
bell nozzle

13. 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

14. Software Modules Involved
Geometric Shape & Grid
CFD Analysis
Response Surface & Optimization

15. Modeling SolidWorks/ANSYS Initial Designs (from previous work/designs)
Final Design (from optimization)

16. CFD Analysis LOCI 2-D/3-D flow analysis Hot flow/cold flow

17. Optimization Process ModeFrontier Optimization of nozzle parameters
Response Surface
Evolutionary Based Algorithm
Particle Swarm (PS)
Optimal Solution

18. Manufacturing Dimensional Analysis (small scale)
True scale versus model
Plexiglas design
Alternative Materials being considered

19. Relevant Standards AS 9100 Quality management of aerospace industry
Created by SAE
– Society of Automotive Engineers
ASME Y14.5
Many standards are proprietary

20. Validation
Cold flow testing to be conducted with a compressed air cylinder
Measuring devices:
Thermocouples
Pressure gauge

21. Project Timeline & Responsibilities

22. 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