Flow measurements around a bio-inspired bluff body

The aim of the present study is to design an aero/hydro dynamically efficient bluff body inspired by the denticles of the fastest shark; Isurus oxyrinchus. A novel shape is developed utilizing the real scales of the denticle presented by the available literature. Experiments were carried out in a water tunnel using the Particle image velocimetry technique to obtain the velocity field around the body. In order to understand and compare the aero/hydrodynamic characteristics of the bio-inspired bluff body (bio-body), one of the most studied bluff body shape, i.e. a circular cylinder was involved for all considered parameters. The bio-body was printed using Polylactic Acid (PLA+) as the raw material whereas the circular cylinder was made of smooth Plexiglas. Since the flow around the novel bio-body is highly three-dimensional, various planes and sections were considered for PIV measurements. The evaluated results showed that the bio-body has better aero/hydrodynamic properties compared with the circular cylinder. The features that prove better aero/hydrodynamic characteristics of bio-body over the cylinder are: (I) The reduction of Reynolds stresses in all velocity components; (II) the shrinking of vortex formation length and lessening of turbulence intensity; (III) the eliminated vibrations in the near wake region. It is believed that this study introduces a new inspiration to the bluff body designs in various engineering applications such as unmanned underwater vehicles, submarines, ship hulls, etc.