A review of hydrodynamic wakes research on submerged bodies

Research on the hydrodynamic wakes of submerged bodies is essential for optimizing non-acoustic stealth and enhancing anti-submarine detection capabilities. This review addresses the types, characteristics, experimental and numerical methods, as well as the applications of SAR technology in wake detection. Studies on hydrodynamic wake, dating back to the early 20th century, have focused on the complex fluid structures influenced by environmental factors such as waves, temperature gradients, and water density stratification. Advances in CFD and experimental techniques have improved simulations and observations of these wakes. Hydrodynamic wakes are classified into surface waves (including "V"-shaped wakes and Bernoulli humps), turbulent wakes, and internal wave wakes, each resulting from different physical interactions. Key research methods include water tunnel experiments and numerical simulations, with experiments providing direct observations of wake formation, while simulations offer flexible analysis of complex flow fields. The combination of these methods yields comprehensive insights into wake dynamics. SAR technology has revolutionized wake detection in complex maritime environments by offering all-weather detection, passive modes, and wide-area coverage. However, it faces limitations related to radar parameters, sea conditions, cost, and technical challenges. Future research should focus on integrating numerical simulations, laboratory experiments, and field validation to enhance the detection of weak wakes using deep learning, which would improve generalizability with limited data. This will optimize submerged body designs, reduce costs, and enhance stealth performance.