Low Speed Fluid Dynamics & Aerodynamics
Research is conducted on advanced diagnostics and the fundamentals of turbulent entrainment. Three-dimensional, digital particle image velocimetry with temperature measurement techniques are developed for use in probing turbulent flows. They provide the entire velocity and temperature field within a volume at high temporal and spatial resolution. The effects of acceleration, compressibility, confinement, rotation, stationarity, and stratification on turbulent entrainment are explored. Often, the results are highly counter- intuitive. For example, adding strong, stationary vortices to a turbulent boundary layer results in at least partial relaminarization. Rapid acceleration of the rotation rate of a turbulent vortex reduces its dimensionless entrainment rate (except for Rayleigh-Taylor flows).