Abstract :

I will provide descriptions of various experimental techniques, modeling work, and recent results from our lab. I will start with UCF’s shock tube and laser absorption methods to investigate the oxidation of various hydrocarbon fuels that are relevant to advanced combustion and propulsion systems under practical conditions. The strategy of using shock tubes provide an ideal device for acquiring ignition delay times and species concentration time-histories, while laser-based diagnostic studies are non-intrusive, provide in-situ measurements (e.g., concentration of individual species including trace species, and temperature), and have fast-time response (micro-second). Recent measurements during butanol combustion, a very important emerging biofuel, will be discussed. Also, design and validation of our latest LED-based sensor for simultaneous measurements of CO and CO2 from combustion exhausts will be discussed. The second part of the talk will present state-of-the-art experimental tools – photoionization mass spectrometry using tunable vacuum-ultraviolet synchrotron radiation – to the combustion of next-generation biofuels that may be efficiently produced from biomass by endophytic fungi. The collaborative biofuel development framework in which the PI is an active member, synthetic biologists develop and engineer a new platform for drop-in fuel production (e.g., diisipropyl ketone, DIPK) from lignocellulosic biomass, using several endophytic fungi including Gliocladium roseum. The combustion researchers investigate the fundamental chemistry of compounds produced by synthetic biologists and recommend potential candidates to test in clean high-efficiency advanced homogeneous charge compression (HCCI) engines. This information is then used to construct predictive combustion chemistry models to guide the optimization towards high-performance compounds and recommendations are provided for the bioengineering scale-up of specific metabolic pathways. The third part of the talk will focus on laser ignition as a promising ignition technique with lower ignition energies and ability to ignite leaner mixtures over conventional spark plug ignitions. The recently constructed high-pressure, high-temperature, constant-volume facility at UCF is highly optically accessible, with four windows for Schlieren photography, laser ignition, and more. A pulsed Nd:YAG laser (Quanta-Ray Lab-190) was used to explore the ignition characteristics and burning velocities of methane/air, isooctane/air, and DIPK/air mixtures. Bio : Dr. Subith S. Vasu is an alumnus of IIT Madras (Aerospace Engineering, B.Tech, 2004) and earned his Ph.D. in Mechanical Engineering from Stanford University (2010). He spent a year as a post-doc at the Combustion Research Facility, Sandia National Labs before joining University of Central Florida in 2012 as an assistant professor in the Mechanical and Aerospace department. Dr. Vasu’s research and teaching interests are in combustion science, alternative fuels, laser diagnostics and sensors, shock wave physics and chemistry, laser spectroscopy, and advanced propulsion. He is active in various professional services and is currently serving on the editorial board of several journals. He is the author of more than 50 journal and conference articles including one article in the prestigious Science magazine. His article has been featured as a cover article in combustion and flame journal. Two of his papers are among the most-cited (since 2007) articles in combustion and flame and shock waves journals. He is also a reviewer for numerous journals and conferences, and has been invited to serve as a panelist for National Science Foundation panels. He has worked on projects funded by the following organizations: DOE, NSF, GE, Raytheon, ARO, Siemens, and NASA. ALL ARE WELCOME