An experimental and numerical investigation of drag reduction through biomimetic modelling

This paper characterises flow around a circular cylinder and investigates the potential of a non-smooth surface to reduce air resistance in a Reynolds number range between Re
_d
= 8.09 10
⁴
and Re
_d
= 2.02 10
⁵
. The two- and three-dimensional numerical simulations were performed using a steady-state solution and the Reynolds-averaged Navier-Stokes (RANS) approaches. Three different mesh designs and four turbulence models with various treatments were assessed and compared against experimental data. A total of 26 uneven preparations in the two-dimensional analysis and two riblet structures in the three-dimensional analysis were designed to investigate the effect of drag reduction. The results reported hold the potential of uneven structures to reduce the air resistance in the case of a circular cylinder. This research further demonstrates that engineering applications can benefit from mimicking nature's details and functions.