NSF Young Investigator

ABSTRACT CTS-9457014 University of Minnesota P.I.: Ellen Longmire This research over the next year will include several projects in the field of experimental fluid mechanics: Particle-turbulence interaction near solid surfaces, investigation of model downbursts, effects of trailing edge geometry on jet mixing, and the effect of flow structure on liquid sprays. In the first set of experiments, we are examining the motion of particles in a lightly-laden impinging jet. Particle image and particle tracking velocimetry are use to measure particle velocities and trajectories in the presence of coherent vortices of known scale. Separate experiments with high particle mass loadings will attempt to examine turbulence modification by the particles and any resulting heat transfer modification when the impingement surface is heated. In the downburst study, we will obtain horizontal velocity fields with PIV to examine both the development of azimuthal instabilities and near-ground velocity gradients. In the jet study, we will perform flow visualization and velocity measurements to understand parametric effects on mixing in round jets with stepped and sawtooth trailing edges. Finally, we will design and construct a facility for the study of sprays subject to varying turbulence level and structure.