Krithika Narayanaswamy

Assistant Professor
Computational Chemistry & Combustion group,
Thermodynamics and Combustion Engines Lab,
Department of Mechanical Engineering,
Indian Institute of Technology Madras,
Chennai - 600036
Email: krithika (at) iitm (dot) ac (dot) in

Research Experience
Faculty page
Scholar page
ResearchGate page

My research focuses on development of chemical kinetic models to describe oxidation of fuels. I am interested in predicting global combustion characteristics of conventional and alternative fuels and interpreting these observations based on insights gained from molecular level kinetic descriptions.

If you are interested in being a part of our team, peruse the list of available projects to identify your interests and write to me with a subject line that includes the title of the topic.

Abstracts for topics floated for MS/PhD admissions (Winter 2017)

Possible M. Tech/DD projects

Research highlights


An alternative way to formulate transportation fuels surrogates using model predictions of gas-phase combustion targets is explored and compared to conventional approaches. This study suggests that in a computational modeling context, surrogate compositions should be determined not just based on global characteristics, as has been done so far, but also on the characteristics and predictive capabilities of the chemical kinetic mechanism used for the simulations.

An accurate, fast, direct and robust algorithm to compute multi-component diffusion velocities has been proposed. To our knowledge, this is the first provably accurate algorithm scaling at a computational complexity of O(N) in nite precision. The above figure compares the total time taken by our proposed fast algorithm to compute diffusion velocities versus the total time taken by the iterative biconjugate gradient method.

A flexible and evolutive component library framework has been proposed to derive short chemical mechanisms with only the necessary kinetics for the desired surrogate mixture. Figure showd the chemical model developed our earlier works reorganized into this framework. A script to extract a chemical mechanism for a surrogate mixture, the kinetics of whose individual components are described in this parent chemical mechanism, is available under the tab publications


Ignition delay times of JP-8/Jet-A fuels at stoichiometric fuel/air equivalence ratios: Symbols - experimental data from several sources. Simulations are performed by representing the real jet fuel as a surrogate containing 30.3% n-dodecane, 21.2% m-xylene, and 48.5% methylcyclohexane (mole %). The kinetics of this surrogate mixture are extracted from a multi-component reaction mechanism using the component library approach.


Research Team

Our research focuses on development of chemical kinetic models to describe oxidation of fuels. I am interested in predicting global combustion characteristics of conventional and alternative fuels and interpreting these observations based on insights gained from molecular level kinetic descriptions. In the recent times, my team has been studying kinetics of oxygenated fuels, which being renewable and resulting in reduced emissions, are immediately relevant to the country's energy needs.

If you are interested in being a part of our team, peruse the list of available projects to identify your interests and write to me with a subject line that includes the title of the topic.


  • Kinetics of biodiesel surrogate components:

    One of our recent interests concerns with developing a kinetic scheme for a small ester, which is a potentially important candidate to represent the longer chain molecules in the real biodiesel fuel, namely methylbutanoate. A compact reaction scheme is derived for methylbutanoate from an existing detailed mechanism, revised based on newer experimental measurements and theoretical rate constant calculations, and comprehensively assessed for its component kinetic description. Thereafter, a constrained optimization approach is used to propose a surrogate to represent biodiesel fuel, consisting of methylbutanoate and n-dodecane, and assessed thoroughly (Fig. below). This work serves as our first step towards the development of a compact reaction scheme for a biodiesel surrogate which will be coupled with combustion studies to investigate the use of biodiesels and its blends with diesel in CI engines.


    Fig: Species profiles in a jet stirred reactor at P = 1 bar, phi = 1.5; symbols: experiments for biodiesel, solid lines: Surrogate A, dashed lines: Surrogate B
    (presented at the 10th U.S. National Combustion Meeting, 2017)

    Most of the available studies are on high temperature kinetics of methyl butanoate oxidation, while some differences are noted between existing ones at lower temperatures. We are collaborating with PTB, Germany to investigate this aspect using Rapid Compression Machines, through which ignition delays of methylbutanoate at the low and intermediate temperatures (T<1000 K), have been measured. Our present work focuses on with developing a kinetic model for methylbutanoate to explain these experimental observations in addition to the ones already in literature.

Aditya Dilip Lele

Aditya obtained his B. Tech in Mechanical Engineering from Vishwakarma Institute of Technology, Pune in 2015. He is currently pursuing his Masters at IIT Madras, on the broad topic of kinetic modeling and combustion simulations of biodiesel fuel. His thesis is co-advised by Dr. K. Anand at IIT Madras.
  • Extinction studies of oxygenated fuels:

    Addition to oxygenates to diesel fuel has been found to reduce soot emissions. Nonetheless, the resulting changes in the extinction and auto-ignition characteristics of the fuel mixture have not yet been fully understood. Considering two important oxygenates, dimethyl ether and methanol, we undertook a fundamental analysis, which reveals that blending small amounts of oxygenates with diesel increases its resistance to extinction, which can be of use in applications such as burners, furnaces and pre-vaporizers. We also find that the auto-ignition characteristics are not altered much due to blending. This study suggests that in the presence of oxygenate, a combustion system can be made more stable even at higher strain rates and at the same time operate with reduced emissions. We are in process of confirming our observations with an experimental study in a counterflow configuration


    Fig: Diesel and blends of diesel and oxygenates: Variation of fuel mass fraction, YF,1, as a function of strain rate at extinction, a2,E
    (presented at the 10th U.S. National Combustion Meeting, 2017)


Rohit Sanjay Khare

Rohit obtained his B. Tech in Mechanical Engineering from Vishwakarma Institute of Technology, Pune in 2015. He is currently pursuing his Masters at IIT Madras. His primary focus is on fundamental studies of extinction strain rates of oxygenated fuels and their blends with conventional fuels. His thesis is co-advised by Dr. V. Raghavan at IIT Madras.


  • Compact kinetic model for methyl methacrylate oxidation:

    Study of kinetics of methylmethacrylate, which is a monomer of PMMA that is used in construction sector, is relevant to fire research. A compact reaction model to describe its oxidation is being developed and validated against fundamental experimental datasets obtained in canonical configurations, which isolate the kinetics from the flow related complexities.



    Fig: Species profiles of Laminar flat flame at atmospheric condition; symbols: experimental data of major species, dashed lines: simulations


Shanmugasundaram D

Shanmugasundaram obtained his B. Tech and M. Tech in Mechanical Engineering from Pondicherry Engineering College, Puduchery in 2014 and 2016 respectively. He is currently pursuing his PhD at IIT Madras. His project revolves around chemical kinetic modeling and reactive simulations of fuels relevant to fire research, one among them being methylmethacrylate. His thesis is co-advised by Dr. V. Raghavan at IIT Madras.


Collaborations

Alumni

  • M. C. Sanjay (M. Tech 2017): SMILES based interface to Thermodynamic Property Estimation Using THERM
  • T. V. Vaisakh (M. Tech 2017): Reaction mechanism optimization
  • Kiran Kumar Yalamanchi (Dual Degree 2017)
  • Ankit Jain (Dual Degree 2017)

Open source codes

Conference proceedings

2017 -- Present

  • A. D. Lele, K. Anand, K. Narayanaswamy, "Development of a chemical kinetic mechanism for biodiesel surrogate", 10th U.S. National Combustion Meeting, 2017.

  • R. Khare, V. Raghavan, K. Narayanaswamy, "Study of auto-ignition and extinction characteristics of diesel blended with oxygenates in laminar opposed non-premixed flames", 10th U.S. National Combustion Meeting, 2017.

  • M. Hunyadi-Gall, G. Mairinger, R. Khare, K. Narayanaswamy, V. Raghavan, K. Seshadri, "The Influence of Stoichiometric Mixture Fraction on Extinction of Laminar, Nonpremixed DME Flames", 10th U.S. National Combustion Meeting, 2017.

Journal publications

Write-up coming soon ...

Abstracts for topics floated for MS/PhD admissions (Winter 2017)

M. Tech/DD projects

  • ME6150: Numerical methods in thermal engineering - Course contents
    Jan-May 2016
    Jan-May 2017

  • ME1100: Undergraduate thermodynamics - Course contents
    Jul-Nov 2016

  • ME6060: Combustion Fundamentals - Course contents
    Jul-Nov 2017

Alma mater

Vivekananda Vidyalaya, Perambur
DAV Girls, Gopalapuram
Indian Institute of Technology Madras
Stanford University
Cornell University

Useful web-based tools

Web plot digitizer
Coding ground
WriteLaTeX
Detexify
WordClouds