• Miniature combustion systems — liquid-fueled engines with combustion chambers on the order of a centimeter can provide extremely high power density but they suffer from low efficiency. Efficiency loss comes from leaks, heat losses, and incomplete combustion due to quenching. These studies examine novel approaches to overcome these losses, including burning a fuel film from off the wall of the combustion chamber.
• Electrical aspects of microgravity combustion — examines various uses of electric fields relevant to flames in zero-g conditions; includes fire suppression, control of the local buoyancy field, and real-time flame manipulation.
• Optical particle sizing -- techniques to measure the size of airborne droplets and particles using laser light scattering.
• Laser spectroscopy for combustion diagnostics -- application of coherent anti-Stokes Raman scattering (CARS), degenerate four-wave mixing (DFWM), and laser induced fluorescence (LIF), and resonant holographic interferometry (RHI) for measuring temperature and species concentrations in combustion environments.
• Homogeneous charge compression ignition IC engine -- An HCCI engine at small scale (25 cc).
• Droplet stream control -- manipulating the driving disturbance on a liquid jet to produce controlled droplet breakup.
• Combustion control -- active control of vortical structures in a Wolfhard-Parker slot burner (with F. Jabbari) and oscillations in a Rijke tube.
• Coal and biomass combustion -- identifying the critical conditions controlling char burnout using a small solid fuel entrained flow reactor.
• Water in oil emulsions -- formation and stability of emulsions and their behavior as sprays.
• Ammonium bisulfate formation -- creation of ammonium bisulfate under conditions simulating flue gas in an air preheater.
• Nonlinear spectroscopy for biological applications -- fiber optically delivered in-situ measurement of tissues.