Acquisition of Laser Doppler Velocimetry System for Turbulence Research

Seattle University, Seattle WA

Investigators

Abstract

ABSTRACT Proposal No. CTS-0421561 Principal Investigator: P. W. Fontana, Seattle University This grant is for acquisition of a laser Doppler velocimetry (LDV) system for use in turbulence research in the Fluid Turbulence Laboratory at Seattle University. The initial investigations in which this instrument will be used involve the phenomenon of sheared flow suppression of turbulence. This phenomenon is not yet fully understood, but is believed to be responsible for the restriction of airborne particulates from volcano eruptions from entering or leaving the equatorial jet, the persistence of the ozone hole in the South Polar vortex, and the good confinement seen in the best fusion reactor discharges. This experiment will be a study of sheared flow suppression of turbulence in a controlled and comprehensive way by inducing turbulent sheared flows in suspended surfactant layers and directly measuring the effects of the shear on transport. Analysis of the results will enable the first systematic quantitative comparison of experimental data with the emerging theory. The LDV is an essential diagnostic for this research because it will provide the time-resolved data needed to analyze the dynamics of the flow. The instrument will significantly broaden the scope and impact of the results to be achieved in these experiments. The LDV is also versatile, and will continue to be a central element of the laboratory as the research expands beyond these initial experiments. This research is motivated by and has direct bearing on current issues in fusion energy research. The pursuit of this limitless source of clean energy has become a renewed national and international priority. Seattle University is a primarily undergraduate institution, so this project will afford undergraduates an opportunity to participate at the frontiers of science. The teaching curriculum will also benefit from the presence of this state-of-the-art LDV system, and the laboratory will promote recruitment of highly-qualified students in the sciences and engineering. The university and its College of Science and Engineering have large enrollments of underrepresented groups and women, so these groups particularly will gain from the research opportunities and teaching enhancements promised by this project.