・Title：Premixed Combustion Characteristics Research at IIST

・Speaker’s Name and Affiliation：Prof. Prathap Chockalingam, Indian Institute of Space Science and Technology (IIST), India

（Dr. Prathap Chockalingam is a Professor at the Indian Institute of Space Science and Technology (IIST), Thiruvananthapuram. His research focuses on combustion science, particularly premixed flames, laminar burning velocity, low-emission combustion systems, and direct contact condensation under cryogenic conditions. He has established advanced experimental facilities for combustion diagnostics and direct contact condensation studies, including optical cryogenic chambers for flow visualization. He has guided several doctoral and postgraduate students and has contributed to multiple sponsored research projects in collaboration with national agencies and industry. His work aims to improve combustion efficiency, reduce emissions in energy and propulsion systems, and advance the fundamental understanding of direct contact condensation at cryogenic temperatures and elevated pressures. ）

・Time: Tue., May 26, 10:30–11:30

・Venue：A3-131, Faculty of Engineering, Hiroshima University

・Abstract：The combustion characteristics of premixed gaseous and liquid fuels—particularly laminar burning velocity (LBV) and ignition delay—are systematically investigated at the Indian Institute of Space Science and Technology (IIST). The unstretched laminar burning velocity is primarily measured using the freely expanding spherical flame method, complemented by high-speed shadowgraphy for accurate flame propagation tracking. A distinctive aspect of our methodology is the introduction of diluents as an independent third-component species, ensuring that their concentration remains invariant with respect to equivalence ratio. The experimental investigations are conducted over a wide range of initial conditions, with temperatures spanning 300–500 K and pressures ranging from 1 to 5 bar. In this talk, we will present results on the laminar burning velocity of n-CH₄/dodecane–O₂ mixtures diluted with CO₂, N₂, and H₂O, with particular emphasis on the influence of radiative heat losses. In addition, ignition delay measurements have recently been initiated using a shock tube facility, employing unsteady pressure-based diagnostics. Lean blowout (LBO) characteristics are studied using swirl-stabilized flames, and the behavior of butane–air mixtures in swirl burners will also be discussed, with a focus on flame stability and flow–flame interaction dynamics.