GLOBAL COMBUSTION RESPONSES OF PRACTICAL HYDROCARBON FUELS: n-HEPTANE, iso-OCTANE, n-DECANE, n-DODECANE AND ETHYLENE by KAMAL KUMAR Submitted in partial fulfillment of the requirements For the degree of Doctor of Philosophy Dissertation Adviser: Prof. Chih-Jen Sung Department of Mechanical and Aerospace Engineering CASE WESTERN RESERVE UNIVERSITY May, 2007 CASE WESTERN RESERVE UNIVERSITY SCHOOL OF GRADUATE STUDIES We hereby approve the dissertation of ______________________________________________________Kamal Kumar candidate for the Ph.D. degree *. C.J. Sung (signed)_______________________________________________ (chair of the committee) J. Iwan D. Alexander ________________________________________________ J.S. T'ien ________________________________________________ T.A. Zawodzinski ________________________________________________ ________________________________________________ ________________________________________________ (date) _______________________01/18/2007 *We also certify that written approval has been obtained for any proprietary material contained therein. Table of Contents List of Tables ................................................................................................................... vii List of Figures................................................................................................................. viii Acknowledgment............................................................................................................ xiv Abstract............................................................................................................................ xv Chapter 1 ........................................................................................................................... 1 Introduction................................................................................................................... 1 1.1 Background......................................................................................................... 1 1.2 Global Combustion Responses.......................................................................... 2 1.3 Objectives............................................................................................................ 4 1.4 Structure of Dissertation ................................................................................... 5 Chapter 2 ........................................................................................................................... 9 Experimental Specifications......................................................................................... 9 2.1 Flame Speed Measurements.............................................................................. 9 2.1.1 Counterflow Burner Apparatus ................................................................ 9 2.1.2 Fuel Vaporization and Premixing ........................................................... 11 2.1.3 DPIV Specifications .................................................................................. 14 2.1.4 Laminar Flame Speed Determination..................................................... 17 2.2 Extinction Stretch Rate Measurements.......................................................... 21 2.3 Ignition Delay Measurements ......................................................................... 22 iii Chapter 3 ......................................................................................................................... 34 Computational Specifications .................................................................................... 34 3.1 Laminar Flame Speed Computations............................................................. 34 3.2 Extinction Stretch Rate Computations .......................................................... 37 3.3 Ignition Delay Computations............................................................................... 41 Chapter 4 ......................................................................................................................... 44 Laminar Flame Speeds of Preheated iso-Octane/O2/N2 and n-Heptane/O2/N2 Mixtures....................................................................................................................... 44 4.1Scientific Background............................................................................................ 44 4.2 Experimental Results ....................................................................................... 47 4.2.1 Iso-Octane/O2/N2 ....................................................................................... 47 4.2.2 N-Heptane/O2/N2 ....................................................................................... 48 4.2.3 Comparison ............................................................................................... 49 4.2.4 Effect of Nitrogen Dilution....................................................................... 50 4.3 Sensitivity Analysis........................................................................................... 52 4.4 Concluding Remarks........................................................................................ 53 Chapter 5 ......................................................................................................................... 64 Laminar Flame Speeds and Extinction Limits of Preheated n-Decane/O2/N2 and n-Dodecane/O2/N2 Mixtures....................................................................................... 64 5.1 Scientific Background...................................................................................... 64 5.2 Experimental Results ....................................................................................... 67 5.2.1 Laminar Flame Speed Results ................................................................. 67 5.2.2 Overall Activation Energy Results.......................................................... 69 iv 5.2.3 Extinction Stretch Rate Results............................................................... 70 5.2.4 Flame Structure Response to Stretch Rate Variations.......................... 73 5.3 Sensitivity Analysis........................................................................................... 74 5.4 Concluding Remarks........................................................................................ 76 Chapter 6 ......................................................................................................................... 93 Laminar Flame Speeds and Ignition Delays for Ethylene/Oxidizer Mixtures ...... 93 6.1 Scientific Background...................................................................................... 93 6.2 Experimental and computational specifications............................................ 95 6.2.1 Determination of Laminar Flame Speed ................................................ 95 6.2.2 Determination of Ignition Delays ............................................................ 96 6.2.3 Kinetic Models........................................................................................... 96 6.3 Results and Discussions ................................................................................... 97 6.3.1 Laminar Flame Speeds............................................................................. 97 6.3.2 Ignition Delays......................................................................................... 101 6.4 Concluding Remarks...................................................................................... 106 Chapter 7 ....................................................................................................................... 121 Autoignition of n-Decane/Air Mixtures .................................................................. 121 7.1 Scientific Background.................................................................................... 121 7.2 Experimental and Computational Specifications........................................ 124 7.2.1 Determination of Ignition Delays .......................................................... 124 7.2.2 Kinetic Models......................................................................................... 125 7.3 Ignition Delay Results......................................................................................... 126 7.4 Concluding Remarks...................................................................................... 133 v Chapter 8 ....................................................................................................................... 152 Autoignition of Binary Fuel Blends involving n-Decane: Influence of Fuel Structure .................................................................................................................... 152 8.1 Scientific Background.................................................................................... 152 8.2 Experimental and Computational Specifications........................................ 154 8.2.1 Determination of Ignition Delays .......................................................... 154 8.3 Ignition Delay Results .................................................................................... 155 8.4 Practical Implications .................................................................................... 159 8.5 Concluding Remarks .......................................................................................... 161 Chapter 9 ......................................................................................................................