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High-Lewis Number Premixed Flame Instabilities

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High-Lewis Number Premixed Flame Instabilities High-Lewis Number Premixed Flame Instabilities A Thesis Submitted to the Faculty of Drexel University by Yi Ma in partial fulfillment of the requirements for the degree of Doctor of Philosophy September 2009 ii Acknowledgements It has been a great blessing being a graduate student under the supervision of Dr. Howard Pearlman. My appreciation of his generosity, tolerance, support and guidance through my long journey of Ph.D. study is beyond words. He is not only a very knowledgeable scholar but also a very kind and inspiring person. What I have learned from him will benefit me for my whole life. In addition, I would like to thank my committee members, Dr. Nicholas P. Cernansky, Dr. David L. Miller, Dr. Alan Lau and Dr. Smitesh Bakrania for their time and energy to review this dissertation. I must acknowledge a few of my colleagues in Hess Lab, Mike Foster, Rodney Johnson, Ashutosh Gupta, and Seul H. Park, among others, and my best friend Meline Zeng for their friendship and assistance for all these years. I would also like to thank two former undergraduate students, Christopher Ricciuti and Brian Fellon, for their contribution to the nano-size catalytic platinum particle project. Finally, the staff at the Machine Shop, namely Mark Shirber and Richard Miller have been very helpful modifying my experimental facility during various stages of this research. I would like to give special thanks to my husband David B. Lenhert for his endless love, tremendous help and encouragement during my Ph.D. study. Finally, my thanks go to my parents Zhong Hejiao and Ma Qingyun for their unconditional love, care and support over the years. This work was partially funded by NASA Office of Biological and Physical Research Grant (Grant No. NCC3-854) and NSF CBET Combustion and Plasma Systems (Grant No. 0755740). Their funding was greatly appreciated. iii Table of Contents LIST OF TABLES ......................................................................................................... VIII LIST OF FIGURES ........................................................................................................... X ABSTRACT ..................................................................................................................... xix 1. INTRODUCTION ...................................................................................................... 1 1.1 Overview ................................................................................................................. 1 1.2 Background and Literature Review ........................................................................ 5 1.2.1 Diffusive-Thermal Cellular Instability (Le < 1) ............................................... 6 1.2.1.1 Linear Stability Analyses ............................................................................ 8 1.2.1.2 Nonlinear Stability Analyses ...................................................................... 9 1.2.1.3 Experimental Studies on Cellular Flames ................................................. 10 1.2.2 Diffusive-Thermal Pulsating Target and Rotating Spiral Flame Instabilities (Le >> 1) ......................................................................................................... 13 1.2.2.1 Theoretical and Numerical Studies ........................................................... 13 1.2.2.2 Experimental Studies on Target and Spiral Patterns................................. 18 1.2.3 Coupled Effects of Hydrodynamic and Diffusive-thermal Instabilities ......... 26 1.2.4 Summary of Past Work ................................................................................... 31 1.3 Motivation for the Present Work .......................................................................... 32 1.4 Outline of Dissertation .......................................................................................... 34 2. EXPERIMENTAL APPARATUS AND METHODOLOGY .................................. 36 2.1 Overview ............................................................................................................... 36 2.2 Variable Pressure Chamber System (VPCS) ........................................................ 38 2.2.1 Variable Pressure Chamber............................................................................. 39 2.2.2 Pressure Control System ................................................................................. 41 iv 2.2.3 Ignition System ............................................................................................... 43 2.2.4 Mass Flow Control System (MFCS)............................................................... 44 2.2.5 Imaging Diagnostics and Instrumentation ...................................................... 46 2.3 Liquid Fuel Vaporization Systems........................................................................ 47 2.4 Experimental Methodology and Parameter Calculations ..................................... 54 2.4.1 Variable Pressure Environment ...................................................................... 54 2.4.2 Calculation of Le for multi-component mixtures ........................................... 55 2.4.3 Error Analysis ................................................................................................. 59 2.5 Closure .................................................................................................................. 60 3. EXPERIMENTAL STUDIES ON HIGH-LEWIS NUMBER PREMIXED GAS FLAME INSTABILITIES .......................................................................................... 61 3.1 Introduction ........................................................................................................... 61 3.2 New Observations of High-Lewis Number Burner-Stabilized Premixed Gas Flame Instabilities in n-Butane-O2-Inert Premixtures .......................................... 64 3.2.1 Flame Patterns in n-C4H10-21%O2-balance He Premixtures on a Stainless- Steel McKenna Burner .................................................................................... 66 3.2.2 Stability Diagram for n-C4H10-21%O2-balance He on a Stainless-Steel McKenna Burner ............................................................................................. 73 3.2.3 Effect of Enriched Oxygen on Burner-Stabilized, Helium Diluted Premixed Gas Flame Instabilities .................................................................................... 74 3.2.4 Comparison of Premixed n-C4H10-21%O2-balance He Results Using Stainless-Steel and Bronze McKenna Burners ............................................... 77 3.2.5 Radial Propagation Flame Speed of the Circular Waves Associated with Axisymmetric Target patterns ......................................................................... 87 3.2.6 Conduction Heat Loss Calculations ................................................................ 89 3.2.7 Flame Patterns in n-C4H10-Air Premixtures .................................................... 92 3.3 New Observations of High-Lewis Number Burner-Stabilized Premixed Gas Flame Instabilities in n-C7H16-O2-Inert Premixtures ............................................ 93 v 3.3.1 Flame Patterns in n-C7H16-O2-Inert Premixtures using Bubbler Setup on a Stainless-Steel McKenna Burner .................................................................... 93 3.3.2 Flame Patterns in n-C7H16-21%O2-balance He Premixtures using Nebulizer & Spray Chamber Setup on a Stainless-steel McKenna Burner ......................... 96 3.3.3 Flame Patterns in n-C7H16-Air Premixtures using Nebulizer & Spray Chamber Setup on a Bronze McKenna Burner .............................................................. 99 3.3.4 Flame Patterns in n-C7H16-21%O2-balance He Premixtures using Nebulizer & Spray Chamber Setup on a Bronze McKenna Burner .................................. 103 3.4 New Observations of High-Lewis Number Burner-Stabilized Premixed Gas Flame Instabilities in n-C8H18-O2-Inert Premixtures .......................................... 107 3.4.1 Flame Patterns in n-C8H18-Air Premixtures using Nebulizer & Spray Chamber Setup on a Bronze McKenna Burner ............................................................ 107 3.4.2 Flame Patterns in n-C8H18-21%O2-balance He Premixtures using Nebulizer & Spray Chamber Setup on a Bronze McKenna Burner .................................. 109 3.5 Effect of Pressure on the High-Lewis Number Instability Patterns in n-C4H10- 21%O2-balance He flames on a Bronze McKenna Burner ................................. 113 3.5.1 Effect of Pressure on Target Patterns ............................................................ 115 3.5.2 Effect of Pressure on Rotating Spiral Waves ................................................ 119 3.6 Closure ................................................................................................................ 122 4. TWO-DIMENSIONAL MODELING STUDIES ON INSTABILITY PATTERN FORMATION IN PREMIXED GAS FLAMES ...................................................... 124 4.1 Introduction ......................................................................................................... 124 4.2 A Historical Review of Numerical Studies on Target Patterns and Spiral Waves ... ............................................................................................................................. 126 4.2.1 Prior Numerical Results using Scott-Wang-Showalter Model ..................... 126 4.2.2 Prior Numerical Results using Matkowsky’s Spiral Flame Model .............. 129 4.3 New Numerical Studies
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