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

3/21/2017 The Ares 1-X Launched - 2009 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]

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

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

Multidisciplinary Optimization 3/21/2017 Multidisciplinary Optimization The overall field of study originally made in the 1980’s Takes all of the different couplings and puts them together into one big analysis for the overall system.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

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]

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

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

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.

Questions?

Thank you for your time

Works Cited [1] - Constellation program: Ares I-X flight test vehicle. Retrieved from https://www.nasa.gov/pdf/354470main_aresIX_fs_may09.pdf [2] - Constellation. Ares I-X: Let the Stacking Begin. 7 July 2009. Retrieved from https://blogs.nasa.gov/Constellation/2009/07/07/post_1247002324876/ [3] - Smith, Sean. Ares I-X Rolls to the Pad. Digital image. Langley Team Readies for Ares 1-X Launch. NASA, 23 Oct. 2009. Web. [4] - Constellation. Constellation finalizes thrust oscillation fix. 21 December 2009. Retrieved from https://blogs.nasa.gov/Constellation/2009/12/21/post_1261434125038/ [5] - Admin. Lego Multiple Designs. Digital image. Lego Remake - Alternate Model Instructions. Thebrickblogger.com, 13 Sept. 2016. Web. 8 Apr. 2017.