Paul S. Krueger
Department of Mechanical Engineering
B.S., University of California, Berkeley, 1997; M.S., California Institute of Technology, 1998; Ph.D., California Institute of Technology, 2001
Vortex ring formation in starting and pulsed jets for application to propulsion, flow control, and biological locomotion; Quantitative flow visualization
Research Accomplishments and Activities
Rolf D. Buhler Memorial Award in Aeronautics, 1998; Invited talk at the 2001 Liepmann-Ludwieg Seminar in Göttingen, Germany; Richard Bruce Chapman Memorial Award for Distinguished Research in Hydrodynamics, 2001
Highly unsteady fluid flow (i.e., large amplitude variations in velocity) is common in many biological venues, from aquatic locomotion to cardiac flows. The unsteady nature of the fluid mechanics in these cases can lead to very large transient forces, vortex roll-up in separated flows, and thin boundary layers. Many of these features are beginning to be recognized as beneficial in applications ranging from MEMS to propulsion to flow control. My research interests are focused on enhancing the key features of unsteady flows and understanding how to apply them to engineering problems. Current research activities include an experimental study of vortex roll-up and force generation in unsteady jets with the aim of finding optimal pulsing conditions (pulse size and/or pulsing frequency). Quantitative flow visualization techniques such as digital particle image velocimetry (DPIV) are an integral component of the experiments.