Unmanned underwater vehicles (UUVs) are characterized by high maneuverability and can be integrated with traditional geophysical methods to achieve efficient detection based on moving platforms. However, the moving vehicle continuously generates hydrodynamic wake-induced electromagnetic disturbances over a considerable area behind it. We systematically study the distribution characteristics of the electromagnetic field in the wake of an underwater vehicle from the perspective of multi-physics field coupling. Based on electromagnetic field theory and fluid dynamics equations, a coupled model encompassing both electromagnetic and flow fields is established. Numerical simulations are employed to analyze the characteristics of electromagnetic disturbances under different motion conditions. The results indicate that non-negligible wake-induced electromagnetic fields are generated behind the vehicle, and the velocity significantly influences the intensity distribution of the induced electromagnetic fields in the wake region. This holds important implications for noise reduction in underwater vehicles and provides a crucial research foundation for the design of towed detection platforms.

The motion of seawater cutting the geomagnetic field will generate induced electromagnetic field, which is an important part of the electromagnetic field in the Marine environment. In order to enrich the methods for obtaining parameters of Marine dynamic environment and further verify the reliability of the actual electromagnetic field observation results in Marine environment, this paper uses the difference between simulated magnetic field and measured magnetic field to construct an objective function, and proposes a method to invert the velocity profile from the electromagnetic field induced by seawater motion based on the vertical array node observation constrained genetic algorithm. A seawater model is constructed based on the observed velocity data in the South China Sea. The inversion test results show that the inversion velocity has a high correlation with the model velocity and good noise resistance performance under the node constraint. The inversion results of the measured electromagnetic data of the Marine environment in the South China Sea show that the inversion velocity profile is in good agreement with the observed data of ADCP in the overall trend and detail characterization, which verifies that the inversion method has good practical application value.