News

The Department of Energy Science and Engineering at IIT Delhi under the aegis of the Energy Society is organizing a talk by Dr. Rajasegar from Colorado School of Mines.

Date: 21^st July 2025
Time: 4:00 PM 
Venue: DESE Committee Room, Block V, Room No. 343

Seminar Title: Laser Diagnostics for Reactive Flows: From Canonical Flames to Combustion Systems

Seminar Abstract: Achieving robust and efficient combustion under modern constraints—low emissions, fuel flexibility, and high-pressure operation—demands a deep understanding of the complex, unsteady processes that govern reactive flows. In this seminar, we explore the application of laser-based and optical diagnostics to uncover the fundamental and applied physico-chemical mechanisms underpinning combustion, from canonical laboratory flames to optical engines and fire safety scenarios. A significant focus will be on swirl-stabilized lean-premixed combustion—a canonical configuration relevant to gas turbines and aero-engines. We will discuss how advanced diagnostics such as high-speed planar laser-induced fluorescence (PLIF), fuel tracer LIF, filtered chemiluminescence imaging, and tunable diode laser absorption spectroscopy (TDLAS) have been deployed to capture flame stabilization, combustion instabilities, and their control strategies, including plasma-assisted combustion. We will also highlight studies on mesoscale combustion, where burner design is optimized to maximize flame-flame interactions for stable, distributed combustion. These diagnostics provide high-fidelity, spatio-temporally resolved experimental data that have been instrumental in guiding model development, validating computational simulations, and improving our understanding of core combustion physics—including flame response to flow perturbations, instability growth, and pollutant formation. By bridging canonical experiments and real-world systems, this talk aims to demonstrate how optical diagnostics can serve as a cornerstone in the development of next-generation propulsion and energy systems.

Speaker biography: Dr. Rajavasanth Rajasegar is an Assistant Professor of Mechanical Engineering at the Colorado School of Mines, where he leads the Advanced Combustion and Propulsion Diagnostics Laboratory. His research focuses on the development and application of advanced laser-based diagnostics to study reactive flows, with strong relevance to aerospace propulsion, energy systems, and fire safety science. Dr. Raja holds joint appointments with the National Renewable Energy Laboratory (NREL) and is under review for a joint role at Sandia National Laboratories, reflecting his active engagement in national lab collaborations at the intersection of experimental diagnostics, clean energy, and propulsion technologies. His work is supported by multiple U.S. federal agencies, including the Department of Defense (DoD) and the Department of Energy (DOE). He earned his B.Tech in Mechanical Engineering from NIT Trichy (2011), followed by his M.S. (2013) and Ph.D. (2018) in Mechanical Science and Engineering from the University of Illinois at Urbana-Champaign. He completed postdoctoral training at UIUC and Sandia before joining Mines in 2024. Dr. Raja’s research leverages high-speed PLIF, fuel-tracer LIF, chemiluminescence imaging, TDLAS, and spectroscopy to investigate combustion dynamics, instability control (including plasma-assisted combustion), and fuel-air mixing in both laboratory and engine environments. His diagnostics work produces high-resolution, spatio-temporally resolved datasets that are widely used for model development and validation in high-performance propulsion and energy systems.