Ian M. Kennedy
Department of Mechanical and Aeronautical Engineering
2094 Bainer Hall
(530) 752-2796 office
(530) 752-4158 fax
B. Eng. (1975), Sydney University
Ph.D. (1980), Sydney University
PARTICULATE FORMATION IN FLAMES (NSF; Kennedy) - This project is concerned primarily with soot production in turbulent diffusion flames. Laser extinction measurements of soot volume fractions and luminous radiation are made in a wind tunnel under varying conditions of axial pressure gradient. Temperature, velocity and mean gas concentrations are also being measured to determine the impact of pressure gradients on flame structure. A second aspect of this program of research is the use of an isothermal analog of soot formation in a turbulent jet. The relatively slow reaction of NH3 and HCl is used to form NH4Cl particles. Laser visualization of the aerosol is used to discern regions of product formation and biacetyl fluorescence is used to measure the mixture fraction field at the same time.
THERMAL TREATMENT OF HAZARDOUS WASTE (NIH; Kennedy) - Particle formation in a diffusion flame of chlorinated hydrocarbons is being investigated experimentally in a laminar, counterflow diffusion flame. Laser extinction and scattering measurements of the soot aerosol characterize its properties. The impact of the H to Cl ratio on the production of hazardous products of incomplete combustion is studied; the absorption of these gas phase species onto particles is of interest in this project. In the second phase of the project, metal emissions from diffusion flames will be studied. Particular attention will be given to the formation of arsenic and chromium particles in flames.
TURBULENT SPRAYS (AFOSR; Kennedy) - An experiment has been developed to study the dispersion of 50 to 100 mm droplets in a turbulent jet of air. A novel laser scattering and imaging technique permits us to track the motion of these particles through a sheet of laser light so that Lagrangian statistics of droplet dispersion are obtained as functions of time of flight. A droplet lasing technique has been developed that allows us the measure the change of the tagged droplet to within 20 to 50 nm, hence permitting measurements of vaporization rates to be obtained in a turbulent flow. The results will be used to test the validity of current correlations of droplet drag and mass transfer in a turbulent flow.
HEALTH EFFECTS OF ULTRAFINE AEROSOLS (Health Effects Institute; Kennedy) - This project represents a collaboration between researchers in Mechanical and Aeronautical Engineering, Civil and Environmental Engineering and Veterinary Medicine. It aims to determine the consequences for pulmonary health of inhalation of ultrafine aerosols that are generated by combustion sources.
SYNTHESIS OF QUANTUM DOTS OF GALLIUM NITRIDE (Kennedy) - Very small particles of GaN can exhibit interesting properties as a result of their three dimensional spatial confinement. Laser ablation of a gallium target by a UV laser beam is being studied as a promising strategy for the synthesis of GaN. Particles less than 10 nm have been successfully created by this method. Fundamental research into the mechanisms that are involved is required