Seminar of Taaresh Taneja (PhD student, University of Minnesota) on Non-Equilibrium Plasma and its Use in Combustion: A Modeling Perspective

Abstract:

Non-equilibrium or Low Temperature Plasma is a state of a gas which is characterized by a 
difference in the energies of the electrons and other heavy species of the gas. Such a plasma 
typically constitutes of gas molecules, a relatively lower density of ions and rotational, vibra6onal, and electronic excited states, neutral radicals, along with free electrons. Non-equilibrium plasmas can exist at various gas pressures ranging from 0.1 – 106 Pa and gas temperatures, ranging from 100 – 10000 K. Across these wide range of conditions, the physical and chemical properties of the plasma can vary substantially – which make them extremely useful in diverse technological areas such as semiconductor manufacturing, water treatment, medical equipment sterilization, nanomaterial synthesis, chemical reforming, combustion assistance, etc. Between 104 - 106 Pa and 300 – 5000 K, these non-equilibrium plasma discharges can be used for assis6ng combustion. This assistance is provided majorly through two channels – gas hea6ng and chemical radical production. Both these channels can be used to ignite renewable and carbon-free fuels such as ammonia (NH!), which is very difficult to burn, and stabilize flames in challenging conditions such as gas turbines, scramjet, and rocket combustors. Moreover, the chemical pathways introduced by the non-equilibrium of the gas, can also help to lower, or completely prevent emissions from combustion, such as unburned hydrocarbons, soot, CO2, CO and NOx. High fidelity computational simulations (DNS / LES) of non-equilibrium "plasma assisted combuston" (PAC) face various constraints due to the wide- ranging temporal (10-15 – 10-2 s) and spa6al (10-6 – 10-1 m) scales of this problem, which make the system of governing equations very s6ff. Furthermore, the highly coupled interaction of electrostatics, plasma chemistry, combustion chemistry, and turbulent flow renders PAC its mul6-physics nature. This talk will provide an overview of the governing physics, the mathematical formulation of different models, and a few technological applications of non-equilibrium plasma assisted combustion.

Brief Bio-data of speaker: 
Taaresh Taneja is a 5th year PhD candidate at the University of Minnesota (UMN), Twin Ci>es, 
who is currently focused on modeling non-equilibrium plasma assisted combus>on. He works 
with Prof. Suo Yang, in the Computa>onal Reac>ve Flow and Energy Laboratory (CRFEL) at UMN. 
For his research, he has received the UMII MNDrive Fellowship, NSF Supplemental Funding 
Opportunity and the UMN Doctoral Disserta>on Fellowship, along with other travel grants for 
presen>ng his work at conferences. Taaresh has also interned at the Na>onal Renewable Energy 
Laboratory, Colorado and at Sandia Na>onal Laboratory, California during his PhD. Before joining 
UMN for his PhD in 2019, Taaresh worked as a CFD engineer at Johnson Controls India Pvt. Ltd., 
Pune (2017 - 2019). He received his B.E. (Hons) in Mechanical Engineering from BITS Pilani, Goa 
Campus in 2017.