Session: Rising Stars of Mechanical Engineering Celebration & Showcase

Paper Number: 151205

151205 - Plasma in Energy Research 

Plasma – ionized gases comprised of ions, electrons, excited species, etc., holds the key to our future energy and environment. Even though plasma research has existed for more than a century, the recent technological innovations in power electronics and advanced manufacturing have opened the door to a new world for energy researchers. Biswas and his Plasma Power Propulsion Laboratory (3P Lab) at the University of Minnesota Twin Cities uses low-temperature, non-equilibrium plasmas as a tool to access unconventional chemical pathways for clean energy production, high-efficiency propulsion, and cleaner transportation.

In his poster, Biswas will highlight our contemporary state of understanding of plasma applications in energy science and explore the immense future potential of non-equilibrium plasmas for ‘sensing and control’ of combustion instability in gas turbines and afterburners. The study will demonstrate reliably detect and mitigate combustion instabilities using a dual-function non-thermal, low-temperature plasma-assisted ‘sensing and control’ system that a) serves as an onboard diagnostic tool to detect the onset of instabilities via continuous monitoring of flame front ionization, b) dynamically actuates to suppress the combustion instabilities via plasma-enhanced combustion processes. Low-temperature plasma discharges at high-repetition rates (1-100 kHz) can control combustion instabilities via three feasible pathways – thermal, kinetic, and transport. Plasmas have been well-known to promote flame stabilization via heat addition and radical production. Recently, a handful of preliminary studies published in the last five years have demonstrated that pressure oscillations due to combustion instabilities can be substantially reduced via strategically discharging plasma in the combustor. However, the underlying mechanisms through which plasma processes interact with the unstable flame dynamics, instability growth/decay modes, and combustor acoustics at lean conditions remain an open scientific question. Our fundamental research will elucidate the underlying plasma actuation processes to mitigate combustion instabilities at the lean limit. In this study, the onset of combustion instabilities is detected at the plasma electrode tip by measuring combustion-generated electrons and ions that induce ionic currents. If combustion instabilities are detected in the form of fluctuating ionic current or capacitance, a feedback control system will immediately actuate plasma discharges to mitigate/suppress instabilities. The mechanisms through which basic plasma processes interact with highly transient instability phenomena in its early phase (e.g., growth period) is investigated in-depth. The study demonstrates these fundamental processes behind plasma-assisted active control of combustion instabilities in an optically-accessible swirl-stabilized high-pressure (1-10 bar) combustor operating near lean blowoff limit subjected to self- or external-excitation.

A fundamental understanding of the plasma interaction with combustion instabilities is essential to successfully deploy this novel and transformative concept in commercial gas turbine engines. Low operating energy and cost, along with easy implementation and minimal maintenance, make the low-temperature plasma system an ideal candidate for infrequently maintained gas turbine engines operating in ultra-lean conditions. The broader research scope will acquaint the audience with the fascinating world of uncharted and intricate non-equilibrium plasma physics and its potential influence on clean energy and propulsion science.

Presenting Author: Sayan Biswas University of Minnesota

Presenting Author Biography: Dr. Sayan Biswas is an Assistant Professor in Mechanical Engineering at the University of Minnesota Twin Cities. Previously, he was a postdoctoral researcher at Sandia National Laboratories Combustion Research Facility. Sayan earned a Ph.D. in Aerospace Engineering from Purdue University in 2017. He received masters from the University of Connecticut in 2012 and bachelors from Jadavpur University, India, in 2010, both in Mechanical Engineering. At the University of Minnesota, Sayan leads Plasma Power Propulsion Laboratory – 3P Lab, developing innovative and sustainable technologies for clean and efficient future energy. His research utilizes low-temperature plasmas in next-generation of engines, discovers carbon-neutral E-fuels for aviation and transportation, explores advanced energetic materials, and studies the fundamentals of high-speed propulsion.

Authors:

Sayan Biswas University of Minnesota