摘要
Bioinspired superhydrophobic surfaces have been used for drag reduction.However,the secondary structures and the air cushions on these surfaces could be destructed in a flow,losing the effect of drag reduction.Here,a stainless-steel surface with mushroom-like cross-section(SMC)and diamond cavities(SMCD)having a drag reduction rate up to 19.37%is developed by 3D printing.The concealed re-entrant structures in SMCD prevent the infiltration of water into the chamber and form gas cushions,which converts the sliding friction at liquid-solid interface into rolling friction at liquid-gas interface,realizing the drag reduction.Meanwhile,98.3%of air can be maintained in the chamber in a flow with Reynolds number(Re)of 9×10^(5),ensuring the drag reduction in a high-velocity flow.Moreover,the continuous top stainless-steel surface and the supporting mesh network protect the critical re-entrant structures,ensuring the robustness of SMC.With the bioinspired design and one-step additive manufacturing process,SMC holds great potential for large-area production and applications requiring robust drag reduction.
基金
supported by National Natural Science Foundation of China(52373119,52475310)
the National Key R&D Program of China(2022YFB4701000).
