On the usefulness of bilateral comparison to tracking turbulent chemical odor plumes

This article reports on the usefulness of bilateral comparison of chemosens ory information to an animal or agent tracking an odor to its source. Insta ntaneous concentration fields of a chemical plume diffusing in a fully deve loped, turbulent. open channel flow are measured using planar laser-induced fluorescence. The plume is released isokinetically 25 mm above the smooth bed (z(+) = 90), thus transport is mainly due to advection and ambient turb ulence. A spatial cross-correlation function in the spanwise direction give s a strong indication of the relative position of the centerline and distan ce from the source. The relative direction of the plume centerline can be e stimated from the instantaneous concentration. provided the sensors are sep arated by a distance larger than the spanwise integral length scale of the concentration field.