Numerical Simulation of Odor Plume Structure in the Wake of a Commercial Odor-Delivery Device

We conduct numerical simulations to quantify the spatiotemporal dynamics of odor plumes forming in the wake of a Training Aid Delivery Device (TADD). The TADD is a cylindrical glass jar topped with an odor-permeable membrane created for the US Army as an aid for training military working dogs for scent detection and localization. Simulations consist of a coupled solution of the Boussinesq form of the Navier-Stokes equations and the advection-diffusion equation. We simulate odors of varying specific gravities (SG) emanating from a TADD on the floor of a 3D rectangular domain with a cross flow, emulating related experiments performed in a low-speed wind tunnel and presented in a companion poster. We investigate odor plumes for a range of crossflow velocities and odorant SG. Results demonstrate that for SG=1, the odor plume is unimodal with peak concentrations on the centerline directly downstream. For SG>1, heavy plumes interact with the horseshoe vortex that forms around the TADD by creating a structured odor plume that has bimodal peaks away from the centerline and lower concentrations directly downwind.

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