Insights into the Physical and Chemical Effects Governing Auto-ignition and Heat Release in Internal Combustion Engines
Prabhu Selvaraj, Ph.D. Candidate Supervised by Prof. Hong G. Im
Tuesday, November 10, 2020
04:00 PM - 05:00 PM
Abstract:The combustion of petroleum-based fuel leads to the formation of several pollutants. Among them, soot particles are particularly harmful due to their severe consequences on human health. Over the past decades, strict regulations have been placed on automotive and aircraft engines to limit these particulate matter emissions. This work is primarily focused on understanding the fundamental behavior of soot particles and their formation. Though the focus of this work is on soot formation and growth pathways, the study of the gas-phase combustion process is also an integral part to validate the mechanism. A reduced mechanism is developed retaining the larger polycyclic aromatic hydrocarbons (PAHs) species till coronene, based on the KAUST-ARAMCO mechanism. Counterflow diffusion flames emphasizes the simulation of canonical configuration where the reduced mechanism is validated and the soot growth pathways are evaluated. The importance of the significant contribution of larger PAH species on the soot growth pathways in both soot formation (SF) and soot formation/oxidation (SFO) flames is evident in this analysis. The sensitivity of these flames with respect to strain rates, dilution and higher pressures are analyzed. Direct Numerical Simulation (DNS) of two-dimensional counterflow diffusion flames is conducted to understand the impact of vortex interactions on soot characteristics. The results indicate that the larger PAH species contribute to the soot formation in the air-side perturbation regimes, whereas the soot formation is dominated by the soot transport in fuel-side perturbation. The study is further extended to simulate and compare co-flow laminar flame using different statistical moment methods.
Bio:Prabhu Selvaraj is a Ph.D. candidate in the Clean Combustion Research Center, KAUST. He earned his bachelor's degree in Mechanical Engineering from Anna University Chennai, India in 2006 and master's degree in Internal Combustion Engineering from the same university in 2010. He was an engineer in the Combustor Aero Design and Development team at General Electric-Aviation, Bangalore for three years. He joined KAUST in December, 2013 as a Ph.D. student under the supervision of Prof. Hong Im. His research interests include modeling of soot formation in diffusion flames and understanding fundamental aspect of soot formation pathway.