Computational Study of the Wake and Contaminant Transport of a Walking Human

Abstract

The unsteady aerodynamic wake of a human is studied using a time-accurate computational fluid dynamics simulation. Transport of a scalar contaminant, which originates on the body, is also considered. An existing Reynolds-averaged Navier-Stokes solver is modified to include energy, scalar-transport, and thermal buoyancy effects. Structured overset grids are used to discretize the geometry and the flow field. Results indicate two distinct wake regions: an unsteady bluff-body wake behind the torso which is characterized by a mean recirculation zone, and a region of unsteady vortex shedding behind the legs which is dominated by a “jet” of air formed between the legs. A significant downwash occurs behind the body which has the effect of laterally spreading the lower portions of the wake. The magnitude of the scalar contaminant is shown to decay exponentially within the wake and is found to be highly dependent upon the source location.