Research Interests

Numerical algorithms for hyperbolic conservations laws; Scientific computing; Compressible gasdynamics; Fusion plasma physics; Atmospheric flows; Compact FD/FV schemes, ENO and Weighted ENO schemes; Implicit and IMEX time integration; High-performance computing and scalable implementation of high-order algorithms

Experience

  • Computational Scientist, Center for Applied Scientific Computing, Lawrence Livermore National Laboratory
    (February 2018 - Present)
    • Multifluid models and their high-order discretizations for inertial confinement fusion applications
    • High-order spatial discretization and IMEX time integration methods for magnetically confised plasma simulations.
    • Numerical methods for other fluid applications: atmospheric flows, reacting flows, etc.

  • Postdoctoral Research Staff Member, Center for Applied Scientific Computing, Lawrence Livermore National Laboratory
    (October 2015 - February 2018)
    • Application of implicit-explicit time integrators to kinetic simulations of magnetically confined plasmas.
    • High-order numerical methods for tokamak edge simulations.
    • IMEX multirate methods for AMR-capable atmospheric flow solvers.

  • Postdoctoral Appointee, Mathematics & Computer Science Division, Argonne National Laboratory
    (February 2013 - October 2015)
    • Implementation of multi-stage implicit and implicit-explicit (IMEX) Runge-Kutta schemes, and general linear methods with error estimation in PETSc.
    • Application of high-order time-integrators in PETSc to computational physics codes.
    • Scalable implementation of high-order finite-difference methods on peta-scale platforms (specifically IBM BG/Q).
    • Developing high-order finite-difference methods for aerodynamic and atmospheric flows.
    • Simulation of power systems with uncertain inputs using a probabilistic density function method.

  • Fellow, Computation Institute, The University of Chicago
    (March 2015 - October 2015)
    • Semi-implicit and multirate time-integration methods for atmospheric flows
    • Efficient implementation of additive Runge Kutta (ARK) and multirate partitioned Runge-Kutta (MPRK) methods in NUMA (Non-hydrostatic Unified Model of the Atmosphere)

  • Graduate Research Assistant, Alfred Gessow Rotorcraft Center, University of Maryland
    (August 2008 - January 2013)
    • Derived and implemented high resolution, non-oscillatory reconstruction schemes for compressible flows characterized by a large range of length scales
    • Developed a three-dimensional Cartesian incompressible Navier-Stokes solver using the Fractional-Step algorithm for high Reynolds number flows
    • Simulated the interaction of multiple vortex rings with a solid wall
    • Developed a simplified framework for rotorcraft wake modeling by implementing immersed boundaries (for fuselage) and momentum sources (for rotor) in a compressible Navier-Stokes solver

  • Research Assistant, Department of Aerospace Engineering, Indian Institute of Technology Bombay
    (August 2003 - June 2006)
    • Developed and validated a robust, high-order accurate algorithm for ideal magnetohydrodynamics
    • Studied the effect of non-convexity on the convergence of numerical schemes, including non-uniform convergence; refined the use of Monotonicity-Preserving limits on selected characteristic fields to ensure high-order accurate non-oscillatory solutions
    • Generated a multi-block, body-fitted grid for the B2 Stealth Bomber and simulated the electromagnetic scattering with Finite-Volume Time-Domain algorithm for the Maxwell's equations

  • Summer Intern, Infotech Enterprises, Bangalore (Pratt & Whitney Canada Center of Excellence)
    (May 2004 - July 2004)
    • Used commercial software to simulate the effusion cooling of an interface element representing the encasing of a gas turbine engine combustion chamber.

    • Education

    University of Maryland, Applied Mathematics & Statistics, and Scientific Computation
    Doctor of Philosophy, January 2013
    Thesis: Compact-Reconstruction Weighted Essentially Non-Oscillatory Schemes for Hyperbolic Conservation Laws (Adviser: James D. Baeder)

    Indian Institute of Technology Bombay, Department of Aerospace Engineering
    Bachelor of Technology and Master of Technology (Dual Degree), July 2006
    Masters Thesis: Higher Order Non-Oscillatory Schemes in Ideal Magnetohydrodynamics (Adviser: Avijit Chatterjee)

    Other Training Programs
    Argonne Training Program for Extreme Scale Computing (ATPESC), August 3 - 15, 2014, St. Charles, IL
    Computational Machine Learning for Scientists and Engineers, June, 2021, ECE Continuum (University of Michigan)

    Professional Activities

  • Member of the AIAA Atmospheric and Space Environments Technical Committee (2016 - Present).
  • Reviewer for
  • Session Chair/Co-Chair for
    • 7th AIAA Atmospheric and Space Environments Conference (Aviation 2015), June 22 - 26, 2015, Dallas, TX (Numerical Weather Prediction) (with Nash'at Ahmad).
    • SIAM Annual Meeting, July 7 - 11, 2014, Chicago, IL (Numerical Methods in PDE VII).
  • Visiting researcher at
  • Organizer of the LANS Informal Seminar Series at the MCS Division, Argonne National Laboratory (2013 – 2015).

    • Scientific Software Contributions

  • PETSc (Contributor) - Runge-Kutta methods, additive Runge-Kutta methods, general linear methods with global error estimation.
  • NUMA (Contributor) - IMEX time integration, multirate and extrapolated multirate time integration for AMR-based simulations.
  • COGENT (Contributor) - High-order time integration.
  • HyPar (Developer).

    • Technical Skills

  • Programming Languages: C/C++, FORTRAN, MATLAB, Julia, Python
  • High Performance Computing: MPI, OpenMP, HPCTookit, TotalView, Memscape
  • Scientific Visualization Software: Tecplot, LLNL Visit
  • Authoring and Publishing Software: Latex, Microsoft Office
  • Platforms: Unix/Linux (all flavors), Mac OS X, Microsoft Windows

    • Teaching Experience

  • Teaching Assistant, Department of Aerospace Engineering, Indian Institute of Technology Bombay
    (July 2005 - May 2006)
    • Numerical Methods for Conservation Laws (Graduate level) - Taught lecture covering finite-volume methods for the ideal magnetohydrodynamics system; Graded assignments, including coding assignments
    • Compressible Gasdynamics (Junior Year level) - Graded assignments and mid-term examinations

    •