A review on drag reduction technology: Focusing on amphibious vehicles.

Amphibious vehicles have the unique ability to maneuver on land and water, due to their distinctive structural characteristics, their hydrodynamic performance differs significantly from that of ships. With the growing demand for high-speed navigation of amphibious vehicles, research into resistance and methods to drag reduction has become a hot issue. In this paper, drag reduction technology for amphibious vehicles is reviewed based on a thorough analysis of existing research. Various amphibious vehicles from different countries are introduced, outlining their different movement states on the water and classified based on their drag reduction mechanisms. The article explores the working principle and effects of various drag reduction technology from two perspectives: universal technology and amphibious technology. Research indicates that applying fouling and biofouling effect, surface drag reduction, and air injection as universal technology can effectively reduce the sailing resistance of amphibious vehicles. Due to the limitations of universal technology in some special military amphibious vehicles, amphibious technology is discussed as a supplement, such as planing hull, retractable walking mechanism, and drag reduction accessories. Finally, a summary of drag reduction technology for amphibious vehicles is provided, including pertinent design recommendations and an introduction to potential research areas for future development. • Traditional amphibious vehicles are weak in speed, maneuverability, and drag reduction methods. • Turbulence improvement, air injection, hydrodynamic lift, and multi-hulled designs have been validated in the laboratory. • Universal drag reduction technologies can be promoted to amphibious vehicles. • Planing hull, retractable walking mechanism, drag reduction accessory are efficient amphibious drag reduction technologies. • Future works should focus on structural, manufacturing, shape optimization, materials, and control. [ABSTRACT FROM AUTHOR]