1. 3/21/2017
A Couplings Approach to Mitigate Unexpected Behaviors in Large Scale Complex Engineering Systems
Ben Giles
Mentor: Dr. Christina Bloebaum

2. 3/21/2017
The Ares 1-X
Launched
Goal of the Ares rocket group: To create a rocket to allow long term missions, such as trips to the moon and Mars, to be possible. [1]
Made of segments ‘Stacked’ together. [2]
Image 1: Ares 1-X [3]

3. Thrust Oscillation Caused by a coupling effect
3/21/2017
Thrust Oscillation
Caused by a coupling effect
Starts from the flow of the fluid in the engine
Fluid hits connections of the engine/displacements in structure
Creates a Turbulent flow and vortex-shedding
Goes then to the Acoustic modes of the chamber
Vortex Shedding excited the surface of the engine chamber
Final is the Structure's Response
The excited structure, if the Acoustic mode and the structures resonance frequency match, vibrate together.
Causes the whole structure to vibrate drastically
Caused whole Ares 1-X to vibrate in a way where the safety of the crew and the integrity of the rocket were in question.
Started at 110 seconds into flight
Break it down, take your time
Acoustic modes, elaborate on this
Talk about how the vibrations get larger and larger as you get closer to the Acoustics modes
Can talk more about how displacements in the structure/inhibor length can impact the fluid flow

4. NASA’s Solution Addition of dampers
Upper Plane C-Spring Isolator Module
Upper stage fuel tank LOX damper
“The isolators work like shock absorbers to de-tune the vehicle and the LOX damper will counter the vehicle acoustic response by absorbing and disrupting the oscillation. Together these options will give us added confidence in the tuning of the vehicle as we mature the Ares and Orion designs.”[4]
- Jeff Hanley, Constellation Program Manager

5. Multidisciplinary Optimization
3/21/2017
Multidisciplinary Optimization
The overall field of study originally made in the 1980’s
Takes all of the different couplings and puts them together into one big analysis for the overall system.
Want to add more, ask David about this
Image 2: Multidisciplinary Flow Diagram

6. An Analogy, Legos Bin of Lego Pieces = Design Space
Each Individual Brick = Possible Design Aspect/Variable
Adding a piece to a design = Time Moving on/One Iteration
The Final Design is different depending on what design aspects we choose to emphasize and focus on. These may be similar, but yet are completely different.
Image 3: Lego Multiple Designs [5]

7. 3/21/2017
Couplings Analysis
The ways the different subsystems impact the overall Design Structure of a system, as well as other individual subsystems.
To the right: Design Structure Matrixes
Each box is a subsystem
Lines represent the Couplings/effects in between these subsystems
For the Ares 1-X we are looking at the coupling between the Vortex Shedding and Thrust Oscillation
Image 4: Two System Coupling Diagram
Mention how these design variables are the Lego pieces from the original slide. Use the analogy to break it down for the audience
Image 5: Three System Coupling Diagram

8. Value Function Image 6: Value Driven Design Process
3/21/2017
Value Function
Takes the companies intentions and goals for a project and outputs the optimal way to get these results.
In this case, the company is NASA. They desire mission success, a profit, minimize cost, and the safety of their crew. Therefor, the Value Function calculates how they should do this optimally.
Based around a mission to the International Space Station
Based around the 2 stages of the Ares 1 rocket
First stage is variable because of Thrust Oscillation
Second Stage - Constant Delta V. (Amount of energy rocket has to get into orbit)
Image 6: Value Driven Design Process

9. What is to come…
Create an uncertainty model in the research to calculate for the unknowns that we currently have
Will allow us to know more about what we do now know.

10. Questions?

11. Thank you for your time

12. Works Cited
[1] - Constellation program: Ares I-X flight test vehicle. Retrieved from [2] - Constellation. Ares I-X: Let the Stacking Begin. 7 July Retrieved from [3] - Smith, Sean. Ares I-X Rolls to the Pad. Digital image. Langley Team Readies for Ares 1-X Launch. NASA, 23 Oct Web. [4] - Constellation. Constellation finalizes thrust oscillation fix. 21 December Retrieved from [5] - Admin. Lego Multiple Designs. Digital image. Lego Remake - Alternate Model Instructions. Thebrickblogger.com, 13 Sept Web. 8 Apr