BIOLUMINESCENCE IMAGING FOR MEASURING FLUID SHEAR DISTRUBUTIONS

Abstract

The dinoflagellate Pyrocystis lunula emits light in response to water motion. The statistical features of the bioluminescence, emitted by P. lunula, owing to shear stress in oscillatory boundary layer flows over ripped bed were studied in this paper with the aim to develop a new imaging technique for measuring fluid strain rate and shear using plankton that emit light in response to mechanical stimulation. The flash intensity has been found to correlate with fluid strain rate estimated from fluid velocity over ripples. Thus the instantaneous planar distribution of the fluid shear can be estimated from video images of the bioluminescence in a fluid region by using the empirical relation determined in this study.