The characteristic and mechanism of three different shapes of riblets on drag reduction

In order to explore the mechanism of different shapes of the riblets on drag reducing, this paper uses CFD software of three typical ribs for numerical calculation, such as V shaped ribs, interval-triangular ribs and blade-ribs. By changing the values of h/s(height-to-spacing ratio), selected common values h/s=0.5 and h/s=1, explores the rib drag reduction effects. From the different aspects of wall shear stress, near wall surface turbulent kinetic energy, analysis the effects of drag reduction. The results of the study show that: There is a low resistance area of different shapes of the rib bottom, which is the common reason for drag reduction of the ribs. In the prominent top of ribs are higher than that of flat wall shear stress of high resistance area, the effect of reduction depends on the size of that region. And the high resistance area is closely related to the turbulence kinetic energy, by analysis of turbulence could judge the frictional strength of high resistance areas of different ribs.