A review on the research progress of turbulent drag reduction and gas layer stability on superhydrophobic surfaces

Superhydrophobic drag reduction technique has garnered significant attention in recent years due to its outstanding performance in reducing frictional drag, presenting promising application potential in areas such as marine vessels and pipeline transportation. This paper provides a comprehensive review of the wetting theory and slip theory associated with superhydrophobic surfaces, and systematically summarizes the mechanisms of turbulence drag reduction from the perspective of coherent turbulent structures. The research on the combination of superhydrophobic and other drag reduction techniques to improve the drag reduction effect is summarized, focusing on the combined drag reduction of superhydrophobic-riblet. The stability and recoverability of the gas layers on superhydrophobic surfaces are critical for advancing this technology toward practical engineering applications. Consequently, this review places particular emphasis on recent research progress concerning the enhancement and restoration of the underwater gas-liquid interface stability on superhydrophobic surfaces.