Recent studies of the structure and penetration properties of round buoyant turbulent thermals, starting plumes and steady plumes (denoted thermals, starting plumes and steady plumes in the following) in still and crossflowing unstratified uniform environments are reviewed, emphasizing conditions far from the source where the self-preserving flow approximation of turbulence can be applied to simplify correlation of flow properties. Studies of the structure of these flows are mainly limited to steady plumes in still environments finding that complete selfpreserving behavior is dominated by flow radius properties and only is observed at distances greater than roughly 100 source diameters from the source, which is farther from the source and yields narrower flows than previously thought. © 2002 by the author(s). Published by the American Institute of Aeronautics and Astronautics, Inc.