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Compressible Dynamic Stall Control Using Microjets James Jay Beahn Florida State University Libraries Electronic Theses, Treatises and Dissertations The Graduate School 2003 Compressible Dynamic Stall Control Using Microjets James Jay Beahn Follow this and additional works at the FSU Digital Library. For more information, please contact [email protected] FLORIDA STATE UNIVERSITY COLLEGE OF ENGINEERING COMPRESSIBLE DYNAMIC STALL CONTROL USING MICROJETS By JAMES JAY BEAHN A Thesis submitted to the Department of Mechanical Engineering in partial fulfillment of the requirements for the degree of Master of Science Degree Awarded: Fall Semester, 2003 Copyright © 2003 James Jay Beahn All Rights Reserved The members of the committee approve the thesis of James Jay Beahn defended on November 3, 2003. Chiang Shih Professor Directing Thesis Farrukh S. Alvi Committee Member Emmanuel Collins Committee Member Approved: Chiang Shih, Chairperson, Department of Mechanical Engineering C. J. Chen, Dean, College of Engineering The Office of Graduate Studies has verified and approved the above named committee members ii ACKNOWLEDGEMENTS I would like to acknowledge and thank many people for their support, in various ways, of this work. To Dr. Chiang Shih, the directing professor, for his vision and ingenuity in getting this project off the ground from concept and funding through fruition. Also for his consistent attention to detail and making time for his students on a weekly basis to be updated on their work along with weekly suggestions and directions. To Dr. M. S. Chandrasekhara for his support at the Compressible Dynamic Stall Facility at NASA Ames as well as his expertise that allowed this current work to sail with a minimum of laboratory setup time. I would also like to thank him for his academic help in the field of Dynamic Stall and Control which was so clearly beneficial when examining the resulting data. To the many men and women, from directors to machinists and technician, who make the FML at NASA Ames run and for their tailored support when unique problems arose. To the men and women at the Florida State University Fluid Mechanics Laboratory for their support throughout the project with special thanks to Bobby Depriest for his logistical aid in designing, manufacturing, and fixing the testing units. iii TABLE OF CONTENTS LIST OF FIGURES ........................................................................................................................ v ABSTRACT.................................................................................................................................. vii CHAPTER 1 : INTRODUCTION.................................................................................................. 1 1.1 Dynamic Stall.................................................................................................................. 1 1.1.1 Phenomena.............................................................................................................. 1 1.1.2 Exploiting Dynamic Stall........................................................................................ 2 1.2 Literature Review............................................................................................................ 2 1.2.1 Incompressible Dynamic Stall ................................................................................ 3 1.2.2 Compressible Dynamic Stall................................................................................... 4 1.2.3 Control of Dynamic Stall........................................................................................ 6 1.3 Uniqueness of Work ....................................................................................................... 8 CHAPTER 2 : EXPERIMENTAL SETUP .................................................................................. 10 2.1.1 Airfoil.................................................................................................................... 10 2.1.2 Facility .................................................................................................................. 13 2.1.3 Unsteady Pressure Measurements......................................................................... 17 2.2 PDI Technique .............................................................................................................. 19 2.2.1 Governing Equations ............................................................................................ 19 CHAPTER 3 : RESULTS AND DISCUSSION........................................................................... 26 3.2 Qualitative Analysis...................................................................................................... 28 3.2.1 M=0.3, k=0.10 ...................................................................................................... 28 3.2.2 M=0.3, k=0.05 ...................................................................................................... 28 3.2.3 M=0.4.................................................................................................................... 31 3.3 200 µm Microjets.......................................................................................................... 31 3.4 Quantitative Analysis.................................................................................................... 36 3.4.1 Fringe Counting .................................................................................................... 36 3.4.2 Unsteady Pressure Measurements......................................................................... 44 CHAPTER 4 : CONCLUSIONS .................................................................................................. 53 APPENDIX A............................................................................................................................... 55 BIBLIOGRAPHY......................................................................................................................... 68 BIOGRAPHICAL SKETCH ........................................................................................................ 70 iv LIST OF FIGURES Figure 2-1 : Wind tunnel Pitching Mechanism Schematic ........................................................... 11 Figure 2-2 : Photo of Test Unit..................................................................................................... 12 Figure 2-3 : Mass Flow Rate vs. Plenum Pressure Plot................................................................ 12 Figure 2-4 : Photo of Compressible Dynamic Stall Facility at NASA Ames............................... 13 Figure 2-5 : Point Diffraction Interferometry (PDI) Setup........................................................... 15 Figure 2-6 : Pinhole Plate/Beam Separation Schematic ............................................................... 16 Figure 2-7 : Sample PDI Image (Interferogram) .......................................................................... 17 Figure 2-8 : Image of Transducer Wiring..................................................................................... 18 Figure 2-9 : Sample Interferogram with Fringe Labels ................................................................ 24 Figure 3-1 : Flowfield diagram..................................................................................................... 27 Figure 3-2 : Effect of Microjet Control on Dynamic Stall............................................................ 29 Figure 3-3 : Effect of Microjet Control on Dynamic Stall @ k=0.05........................................... 30 Figure 3-4 : Sample M=0.4 Intererogram with λ-shocks ............................................................. 32 Figure 3-5 : Effect of Microjet Control on Dynamic Stall @ M=0.4........................................... 33 Figure 3-6 : Effect of size on microjet control on Dynamic Stall................................................. 35 Figure 3-7 : Effect of 200 µm microjet control on Dynamic Stall compared to 400 µm control. 37 Figure 3-8 : Effect of microjet control on Surface Pressure ......................................................... 39 Figure 3-9 : Effect of microjet control on Suction Peak @ M=0.30 ............................................ 41 Figure 3-10 : Change in Suction Pressure caused by Microjet Control........................................ 43 Figure 3-11 : Optical Encoder Resolution as a function of angle of attack.................................. 44 Figure 3-12 : Unsteady Pressure measurements as a function of angle of attack......................... 46 Figure 3-13 : Unsteady Pressure measurements as a function of angle of attack......................... 47 Figure 3-14 : Plot of Unsteady Pressure measurements, Focused on NPR=2.33......................... 49 Figure 3-15 : Plot of Unsteady Pressure measurements, Focused on NPR=2.42......................... 50 Figure 3-16 : Comparison of Calculated Data with Directly Measured Data............................... 51 v Figure 3-17 : Unsteady Pressure measurements as a function of angle of attack......................... 52 Figure A-1 : Interferogram Series for Upstroke of M=0.3, k=0.05, No Control.......................... 56 Figure A-2 : Interferogram Series for Upstroke of M=0.3, k=0.05, With Control (21psia)......... 57 Figure A-3 : Interferogram Series for Upstroke of M=0.3, k=0.10, No Control.......................... 58 Figure A-4 : Interferogram Series for Upstroke of M=0.3, k=0.10, With Control (21psia)......... 59 Figure A-5 : Interferogram Series for Upstroke of M=0.4, k=0.05, No Control.........................
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