Transient plasma ignition (TPI)
  • Exploring fundamental aspects of advanced ignition systems to enable clean and efficient engine combustion strategies, with a particular focus on transient plasma ignition (TPI) using low-temperature plasma (LTP)

  • Investigated low-temperature transient plasma characteristics using laser measurement techniques such as 2-photon absorption laser-induced fluorescence of atomic oxygen (O-TALIF), Thomson and Raman scattering, Schlieren, ozone absorption and filtered imaging of various radicals

  • Identified dominant chemical pathways for plasma ignition of gaseous and liquid fuels

Ozone added spark assisted compression ignition (SACI)
  • Ozone—a powerful oxidizing chemical agent generated through onboard coronal discharges in intake air—can be used to significantly alter gasoline reactivity, and thereby enable stable auto-ignition with less initial charge heating

  • Ozone addition stabilized combustion relative to similar conditions without ozone by increasing end gas reactivity

  • However, the impact of ozone addition decreased with increased engine speed due to shorter residence times available for auto-ignition

  • Ozone addition can facilitate mixed-mode (SI, ACI, SACI, etc.) combustion

Schlieren, CH* and IR imaging of reacting jet
Supersonic reacting jet ignition for ultra-lean clean combustion
  • Designed and performed experiments to study supersonic hot jet ignition of premixed CH4/air and H2/air​​

  • Hypothesized jet ignition mechanisms (an alternative for spark-ignition engines) for environment-friendly future combustion techniques for automotive and gas turbine applications

  • Characterized turbulent flame propagation using high-speed Schlieren, OH* chemiluminescence, Particle Image Velocimetry (PIV), and Infrared (IR) imaging

  • Proposed a Schlieren based novel velocity measurement technique, Schlieren Image Velocimetry (SIV)

  • Investigated thermo-acoustic combustion instability for ultra-lean limit in constant volume combustor

Advanced combustion modeling with detailed turbulence-chemistry interaction
  • Evaluated emission characteristics (NOx, SO2) of lean CH4/air and H2/air in dual chamber combustor

  • Numerically investigated coupling between chemistry and turbulence of supersonic reacting jet in inert medium using detailed chemistry for hydrogen and natural gas

  • Modeled reacting supersonic jet using Unsteady Reynolds Averaged Navier Stokes (URANS) in ANSYS Fluent, ICEM CFD

High-temperature ignition delay measurements of biodiesel blend
  • Investigated ignition delay of Methyl Ester-based biofuel blends in High Pressure (20-60 atm) and High Temperature (1000-1500 K) Shock Tube (HPHT-ST)

  • Identified chemical mechanisms for biofuel blends based on shock tube data

  • Constructed chemical mechanisms for biofuel blends using reaction path analysis

  • Developed experiments to study CH4/air flame propagation through narrow channel

  • Examined flame propagation, stabilization, and flame extinction limits to develop combustion based micro-power generation systems such as micro aerial vehicles, microsatellite thrusters, and microchemical reactors

Flame propagation in narrow convergent-divergent channel
Ignition by chemically reacting impinging jet and multiple jets
  • Investigated ignition physics by chemically reacting impinging jets to achieve superior control of ignition location and ignition delay

  • Identified the effect of jet interactions during reacting jet ignition process

  • Proposed guidelines for future pre-chamber designs for cleaner and efficient combustion ​​

Bluff-body stabilized turbulent flames in a prototype jet-engine afterburner
  • Researched blowoff dynamics of bluff-body stabilized V-shaped propane/air flames under fuel stratification and self-excited oscillations

  • Quantified flame behavior near blowoff using simultaneous PIV-PLIF and high-speed CH* imaging

  • Performed phase-locked PIV, CH* chemiluminescence, OH-PLIF, and Rayleigh scattering to investigate forced blowoff mechanisms in lab scale burner

Scalar mixing in the field of closely interacting vortex pairs and couples
  • Designed and built experiment to study mixing statistics of interacting laminar vortices

  • Assessed scalar distribution in vortical flow using Planar Laser Induced Fluorescence (PLIF) of acetone

  • Studied flame-vortex interactions