Ph.D. Defense | Ahfaz Ahmed

Jul 12 2018 03:30 PM - Jul 12 2018 04:30 PM

First principles based fuel design: investigating fuel properties and combustion chemistry


Ahfaz Ahmed, Ph.D. Candidate Supervised by Prof. William Roberts & Prof Mani Sarathy


Thursday, July 12, 2018


03:30 PM - 04:30 PM


Al Kindi Building, Bldg 5, Level 5, Room 5209


Advanced combustion engine concepts require fuels which are meticulously designed to harness full potential of novel engine technologies. To develop such fuels, better understanding of fuel properties and their effect on combustion parameters is needed. The investigations reported in this work establishes relationships between several fuel properties and combustion parameters at engine relevant conditions. Further, these findings along with conclusions from other studies are utilized to synthesize fuels and surrogate fuels with tailored combustion properties.

Detailed investigations have been made to understand the effect of fuel properties on the ignition of fuels in rapid compression machines utilizing a custom built multi-zone model. The study was further extended to explore fuel effects on engine combustion utilizing experiments and modelling to gather understanding of instances of engine knocking and pollutant formation.
Ignition characteristics of two high octane bio-blended gasolines were studied experimentally in rapid compression machine and shock tube and detailed chemical kinetic analysis was conducted to understand how the presence of biofuels (i.e., ethanol) in gasoline influences the evolution of important radicals controlling ignition.

Another set of biofuels namely methyl acetate and ethyl acetate were studied employing fundamental experimental and computational methods. The investigation involved development and analysis of combustion chemistry models, speciation studies in jet stirred reactors, ignition delay measurements and determination of laminar burning velocities. These fuels are found suited for high performance advanced spark ignition engines and the developed model and analysis will lead to optimization of combustion performance.


Ahfaz Joined KAUST in fall 2013, before that he worked as an diesel engines development manager at Engineering Research Center, Tata Motors ltd at Pune, India from 2010-2013. In 2010 Ahfaz graduated from IIT Bombay, Mumbai with masters and in 2008 with bachelors from Bhilai Institute of Technology at Durg.