Sarah Adams

Jeremy Blair


Dept. Civil & Environmental Engineering

Senior Thesis Project: 

Plasma-assisted combustion

     Hi! My name is Sarah Adams, and I’m in the Engineering in the Liberal Arts (ELA) program in the Civil and Environmental Engineering Department. I am really passionate about the energy industry, and I used the ELA program to pursue my passions in engineering and economics and entrepreneurship. 

     After I graduate in June 2013, I will be working for NRG Energy as one of the first members of their Innovation and Implementation Group. Our goal is to identify new market opportunities for NRG, and I will be determining the economic and technical feasibility of these new opportunities, in addition to making them happen.

     While I was at Princeton, I conducted a deep-dive analysis on algae biofuels in 2011, and I spent 2012-2013 researching the kinetics behind plasma-assisted combustion for my thesis. Currently, non-equilibrium plasma is known to facilitate low-temperature combustion, which reduces NOx emissions and increases efficiency, but the kinetic reactions that occur during ignition are poorly understood. It was determined that higher voltage and plasma pulses increased the efficacy of combustion, whereas frequency had little effect. Additionally, an economic analysis was conducted to determine the price at which plasma-assisted cars can be competitive with standard cars, hybrids, and electric vehicles, and it was concluded that plasma-cars can be sold at a $1,750 premium based on a 20% increase in fuel efficiency and a 5 year return on investment for the consumer.

(Top) Image of Plasma-Assisted Combustion, which results in evenly distributed combustion and facilitates the ability to burn fuel lean, thereby increasing fuel efficiency

(Bottom) Image of Standard Combustion, which results in “hotspot” formation (localized combustion). Hot spots require higher combustion temperatures to burn all the fuel in the chamber


To see the relationship between voltage and pulse number, this is a comparison of voltage at V1 (10 kV) and V5 (16 kV), frequency at 30 kHz, and pulse number at 20 P and 50 P. The greatest amount of product is generated at V5 and 50 P, and the lowest is at V1 and 20 P. The quantity of product formed is almost the same when there is a high voltage and low pulse number, and low voltage and high pulse number. This indicates that voltage and pulse number have similar effects on product quantity, and when they are combined, the effects are doubled.


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