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Copyright by Kyle Feliciano Chavez 2016 The Dissertation Committee for Kyle Feliciano Chavez certifies that this is the approved version of the following dissertation: Variable Incidence Angle Film Cooling Experiments on a Scaled Up Turbine Airfoil Model Committee: David G. Bogard, Supervisor Frederick Todd Davidson Atul Kohli Ofodike A. Ezekoye Michael E. Webber Variable Incidence Angle Film Cooling Experiments on a Scaled Up Turbine Airfoil Model by Kyle Feliciano Chavez, B.S.; M.S. Dissertation Presented to the Faculty of the Graduate School of The University of Texas at Austin in Partial Fulfillment of the Requirements for the Degree of Doctor of Philosophy The University of Texas at Austin May 2016 Dedication This document is dedicated to my family. Dad, you have always been so encouraging, helpful, and levelheaded. If not for all of your help and encouragement, I’m not sure I’d be where I’m at today. To my brother, I’m so happy for the years we spent growing up together. They are some of my fondest memories and I’ll never forget them. Mom, if you were still here today, you’d be so proud. I think of you all constantly, and I love you all. Acknowledgements I would like to first and foremost thank Dr. Bogard, who has supported and taught me so much along the way. Your dedication to your field of research is an inspiration to me, and you’ve helped shape me in to the engineer I am today. You also taught me how great it is to be “mighty fine” all the time, and that’s priceless in and of itself. I’d also like to thank the Pratt & Whitney team who worked on this project in conjunction with our lab. It was great working with you, and thank you for working so hard to make sure that this project was as successful as it was. I’d like to thank all the graduate students I’ve had the pleasure of working with and meeting. Adam, Dave, Ellen, Emily, Gavin, Jabob (hah), James, John, Josh, Noah, Owen, Robbie, Sean, Tom. I’m so sorry ahead of time for forgetting someone’s name, but you’re all included, I promise. Special thanks to those who spent some of those late nights working with me to meet deadlines. I hope you don’t hate me too much for it. I’d also like to thank all of the undergraduate assistants I’ve had the pleasure of working with – Brad, Chris, Gary, Jennifer, Khanh, Michelle, and Theo. You’ve helped me so much, and I’ll always be thankful for that. Hopefully I taught you something along the way, or at least made you laugh a few times. Finally, I would like to sincerely thank The University of Texas at Austin Cockrell School of Engineering and the W.M. Keck Foundation for providing me with funding assistance. It is an honor to be one of the students receiving a fellowship such as the one that I did, and it allowed me to truly pursue my goals without having to worry about the additional financial burdens that I would have had to overcome. v Variable Incidence Angle Film Cooling Experiments on a Scaled Up Turbine Airfoil Model Kyle Feliciano Chavez, Ph.D. The University of Texas at Austin, 2016 Supervisor: David G. Bogard This study focused on three main areas of research - the development of a new type of low-speed, closed-loop wind tunnel design to test at varying incidence angles, the investigation of film cooling for gas turbine components at varying incidence angles, and the analysis of the heat transfer and flow field predictive capability of RANS models. In order to develop the closed loop wind tunnel, a rigorous design and validation process was followed. This validated design is unique for low-speed closed-loop facilities. The development of this wind tunnel enabled measurements of adiabatic and overall effectiveness of two highly realistic airfoil models with shaped holes at varying incidence angles. This was accomplished through application of the appropriate aerodynamic and heat transfer scaling parameters for all measurements. Among other results, it was found that the shaped holes at the stagnation row of holes significantly enhanced film cooling effectiveness in the high curvature region of the showerhead depending on the incidence angle tested, and that the incidence angle effect persisted on the matched Biot number model. No previous studies had experimentally investigated the effects of incidence angle effects on overall effectiveness of a full-coverage airfoil. Furthermore, no previous studies had investigated the effect of shaped holes in the showerhead region of a realistic airfoil model such as the one used in this study. Finally, the computational predictive vi capability of various RANS turbulence models were analyzed by predicting the heat transfer coefficient of the model as well as the turbulence production and turning angle of a vertical array of rods used to generate turbulence in the tunnel. It was found that the computational predictions of leading-edge heat transfer were under-predicted due to the shape of the model leading edge. It was also found that the SST-Transition model appropriately predicted downstream turbulence and turning angle of the vertical rod array when compared to experimental results and empirical correlations in the literature. This is the first study to experimentally and computationally investigate the turning angle of a vertical grid array over a range of zero and non-zero inlet flow angles. vii Table of Contents List of Tables .........................................................................................................xv List of Figures ..................................................................................................... xvii Nomenclature ................................................................................................... xxviii Chapter 1 : Introduction ...........................................................................................1 1.1. Gas Turbine Engines ..................................................................................1 1.1.1. Materials and Cooling Technologies .....................................................4 1.1.2. Quantification of Cooling Performance.................................................7 1.1.3. Quantification of Aerothermal Performance .......................................10 1.2. Experiments and Computational Fluid Dynamics ...................................11 1.2.1. Reynolds-averaged Navier-Stokes computational models ..................12 1.3. Considerations of Off-Design Incidence ..................................................13 1.4. Gas Turbine Airfoil Nomenclature and Coordinate Systems ...................13 Chapter 2 : Literature Review ................................................................................15 2.1. External No-Film Heat Transfer Coefficient Testing ..............................15 2.2. Adiabatic Effectiveness Testing ...............................................................17 2.3. The Matched Biot Number Model Testing ..............................................22 2.4. Variable Incidence Angle Wind Tunnel Facilities ...................................24 2.4.1. Adjustable Inlet Duct Linear Cascades................................................25 2.4.2. Adjustable Inlet Contraction Nozzle Linear Cascades ........................27 2.4.3. Inlet Guide Vane Cascades ..................................................................29 2.4.4. Rotating Rigs .......................................................................................31 viii Chapter 3 : Dissertation Objectives and Contribution Goals .................................33 Chapter 4 : Previous Facility and Conceptual Design of New Facility .................36 4.1. Previous Facility Components .................................................................36 4.2. Conceptual Design of New Facility .........................................................38 4.2.1. Initial Concept .....................................................................................39 4.2.2. Improvement of Conceptual Design – Design Criteria .......................41 4.2.3. Research for Conceptual Design Improvements .................................42 4.2.4. Improved Designs and Decision Matrix ..............................................42 4.2.5. Revised Design Concept ......................................................................44 Chapter 5 : Detailed Design of Facility Upgrades .................................................46 5.1. Design of Main Components....................................................................48 5.1.1. Contraction Nozzle ..............................................................................48 5.1.2. Incidence Angle Mechanism ...............................................................51 5.1.3. Test Section .........................................................................................59 5.1.4. Diffuser ................................................................................................66 5.1.5. Coolant Loop .......................................................................................70 5.1.6. Construction .........................................................................................71 5.2. : Design of Subcomponents .....................................................................74 5.2.1. Test Airfoils .........................................................................................74 5.2.2. Turning Vanes for Incidence Angle Mechanism .................................79 5.2.3. Turbulence Rods for Test Section Inlet ...............................................85 5.2.4.