Simulation Study of Bionic Jetting Direction Influence on Drag Reduction Effect

By imitating the jetting flow feature of shark gills，a bionic jetting model is established by arranging round outlets on a flat plate. The drag reduction effect under different jetting directions are explored using numerical simulation method when the main flow field velocity was 20m/s and the reasons of drag reduction are analyzed simultaneously. The results of simulation showed that：different jetting directions affecte the wall shear stress and static pressure of flow field which result in the changing of viscous resistance and pressure drag; the bionic jetting has the best drag reduction effect when jetting direction angle is 30 degrees; under different jetting direction conditions, the main reason of drag reduction is the substantially decreased pressure drag. Key words：bionics; drag reduction; jetting flow; numerical simulation; viscous resistance; pressure drag