Marine drag reduction of shark skin inspired riblet surfaces

Shark skin inspired riblet surfaces have been known to have drag reduction effect for the over past 40 years. It first drew the attention from the aircraft industry. With the property of low drag and self-cleaning (antifouling), shark skin inspired riblet surfaces can also be used on navigation objects. In this paper, different marine drag reduction technologies are discussed, and a review of riblet performance studies is also given. Experimental parameters include riblet geometry, continuous and segmented configurations, fluid velocity (laminar and turbulent flow), fluid viscosity (water, oil and gas), and wettability are analyzed. However, force is obtained by area-weighted integral of shear stress distributions. So area of riblet surfaces is a crucial factor which has not been considered in many previous studies. An experiment is given to discuss the impact of area. This paper aims not only to contribute to a better understanding of marine drag reduction, but also to offer new perspectives to improve the current evaluation criteria of riblet drag reduction.