A5003972071- Advanced Combustion Engine Technologies
- Combustion and flame dynamics
- Combustion and Detonation Processes
- Vehicle emissions and performance
- Biodiesel Production and Applications
- Plasma Applications and Diagnostics
- Catalytic Processes in Materials Science
- Fire dynamics and safety research
- Spectroscopy and Laser Applications
- Computational Fluid Dynamics and Aerodynamics
- Rocket and propulsion systems research
- Heat transfer and supercritical fluids
- Wind and Air Flow Studies
- Electrohydrodynamics and Fluid Dynamics
- Atmospheric chemistry and aerosols
- Fluid Dynamics and Heat Transfer
- Atmospheric and Environmental Gas Dynamics
- Laser-induced spectroscopy and plasma
- Catalysts for Methane Reforming
- Thermochemical Biomass Conversion Processes
- Engine and Fuel Emissions
- Plasma Diagnostics and Applications
- Advanced Measurement and Detection Methods
- Light effects on plants
- Particle Dynamics in Fluid Flows
Sandia National Laboratories California
2020-2025
Colorado School of Mines
2024-2025
University of Illinois Urbana-Champaign
2014-2023
Sandia National Laboratories
2021-2023
Energy and conversion efficiencies of the carbon dioxide (CO <sub xmlns:mml="http://www.w3.org/1998/Math/MathML" xmlns:xlink="http://www.w3.org/1999/xlink">2</sub> ) dissociation process at atmospheric-pressure conditions are investigated using a direct-coupled continuous microwave plasma system (MPS). Gas chromatography mass spectrometer measurements were performed on gas mixture postplasma treatment, over range specific energy inputs (SEIs) (0.06–0.6 eV mol <inline-formula...
<div class="section abstract"><div class="htmlview paragraph">Pre-chamber spark ignition (PCSI) systems have been proven to improve combustion stability in highly-diluted and ultra-lean natural gas (NG) engine operation by providing spatially distributed initiated multiple turbulent flame-jets that lead faster compared conventional ignition. This work investigates the physico-chemical processes drive subsequent presence of residuals (internal EGR) within pre-chamber at varying...
<div class="section abstract"><div class="htmlview paragraph">Pre-chamber combustion is an advanced ignition strategy that has been shown to enhance spark (SI) stability in natural gas (NG) engines by providing distributed sites from turbulent jets and enhancing main-chamber turbulence. Pre-chamber proven especially advantageous compared SI ultra-lean dilute operating conditions. This work involves experimental investigation of the effects varying passive pre-chamber nozzle...
The effect of continuous volumetric direct-coupled nonequilibrium atmospheric microwave plasma discharge on swirl-stabilized premixed methane–air flames was investigated using quantitative OH planar laser-induced fluorescence and spectrally resolved emission. found to influence the dynamics flame stabilization, i.e., plasma-assisted stabilized in quiescent center body wake were relatively stable while swirl active inner shear layer prone local extinction due aerodynamic shear. At coupled...
Dual-fuel (DF) engines, in which premixed natural gas and air an open-type combustion chamber is ignited by diesel-fuel pilot sprays, have been more popular for marine use than pre-chamber spark ignition (PCSI) engines because of their superior durability. However, control DF difficult PCSI engines. In this context, study focuses on the stability n-heptane pilot-fuel jets injected into a compressed charge at low-load conditions. To aid understanding experimental data, chemical-kinetics...
<div class="section abstract"><div class="htmlview paragraph">Mixture formation in a hydrogen-fueled heavy-duty engine with direct injection and nearly-quiescent top-hat combustion chamber was investigated using laser-induced fluorescence imaging, 1,4-difluorobenzene serving as fluorescent tracer seeded into hydrogen. The motored at 1200 rpm, 1.0 bar intake pressure, 335 K temperature. An outward opening medium-pressure hollow-cone injector operated two different pressures five...
A versatile portable tunable diode laser based measurement system for measuring elevated concentrations of hydrogen cyanide (HCN) in a time-resolved manner is developed application the fire environment. The direct absorption spectroscopy (DA-TDLAS) technique employed using R11 line centered at 3345.3 cm −1 (2989.27 nm) fundamental C–H stretching band (ν 1 ) HCN spectrum. validated calibration gas known concentration and relative uncertainty 4.1% 1500 ppm. measured with sampling frequency Hz,...
<div class="section abstract"><div class="htmlview paragraph">An optically accessible hydrogen-fueled, heavy-duty engine was used to investigate the impact of mixture formation on early flame kernel propagation and resulting combustion cyclic variability. Direct injection from a centrally mounted medium-pressure outward-opening hollow-cone injector created fuel- air with global equivalence ratio 0.33. The operated at 1200 RPM dry an intake pressure temperature 1.0 bar 305 K,...
Combustion stability is an important consideration for many energy systems because of its impact on performance and efficiency. Flame dynamics that govern combustion are often complex difficult to resolve, particularly from experimental data. However, recent advances in postprocessing techniques, such as dynamic mode decomposition (DMD), have partially enabled flame analysis. This study aims provide a comprehensive measure through detailed investigation coherent structures their contents,...
Development of a stable and efficient small-scale combustor architecture with comparable performance emission characteristics to large-scale burners is presented. Furthermore, the proposed reduced susceptibility extinction maintained high combustion efficiency low levels under ultralean operating conditions for wide range power outputs. Prototype burner arrays were additively manufactured demonstrated methane/air flames. The sustained lean flames (ϕ=0.65) independent output, indicating good...
<div class="section abstract"><div class="htmlview paragraph">Renewably sourced hydrogen is seen as promising sustainable carbon-free alternative to conventional fossil fuels for use in hard decarbonize sectors. As the supply builds up, dual-fuel hydrogen-diesel engines have a particular advantage of fuel flexibility they can operate only on diesel case shortages, addition simplicity engine modification. The compression ignition strategy initiates combustion using short...
<div class="section abstract"><div class="htmlview paragraph">Hydrogen-fueled internal combustion engines are highly susceptible to pre-ignition from external sources due its low minimum ignition energy despite the hydrogen’s good auto-ignition resistance. Pre-ignition leads uncontrolled abnormal events resulting in knocking and / or backfire (flashback) which may result mechanical damage, as such represents tenacious obstacle development of hydrogen engines. Current mitigation...
X-ray phase contrast imaging is conducted at 90,517 Hz on a fuel spray to characterize the breakup of bulk into ligaments and individual droplets in single-sector, swirl-stabilized combustor under reacting conditions. Phase used qualitatively assess for two fuels: Jet-A, which represents normal viscosity fuel, blend JP-5 (64%) farnesane (36% by volume), high-viscosity three fuel-flow rates air inlet temperatures. Time-series images fuels show that atomization occurs much more rapidly higher...
The primary aim of this paper is to establish the effectiveness microwave plasma discharges improve combustor flame dynamics and stability through minimizing heat release fluctuations. A continuous, volumetric, direct coupled, nonequilibrium, atmospheric discharge was applied a swirl-stabilized premixed methane-air minimize combustion instabilities. Proper orthogonal decomposition (POD) used postprocess data extract information on that are usually lost classical statistical approaches. POD...