Evolutions of the electromagnetic signatures induced by the propagating wake behind a submerged body

Abstract

The in situ electromagnetic signatures induced by the movement of conductive seawater in the submarine wake subject to the geomagnetic ambience will provide crucial information for non-acoustic detection. However, several complex multi-physical field coupling processes, for instance, ions concentration variations, turbulent vortex structures, and violent heat and mass transfer have not been systematically investigated, which jointly influence the induced electromagnetic signatures in the propagating stratified wake behind a submerged body. To reveal the interaction mechanisms among flow, heat transfer, ions concentration variations, and electromagnetic fields, we construct a novel multidisciplinary model integrating the mass, momentum, energy, ions concentration, and Maxwell's equations. The pronounced range and intensity of the electromagnetic signatures in the near-field wake are obtained by multi-physics field coupling numerical simulations. The instantaneous visualizations of the near-field wake manifest the distinct fluctuations features, revealing that the magnitude of the induced magnetic intensity can be maintained in the order of 10−10 T. 3D spatial evolutions of the electromagnetic variations are further scrutinized by some quantitative profiles, which indicate that the magnitudes of the wake perturbations fall within the current state of the art instrumentation capabilities. Subsequently, further pertinent analyses about the electromagnetic distributions with different navigational velocities are also explored and reported to elucidate the effects of velocity. These scientific findings provide a conducive insight for lucubrating the evolutions of the induced electromagnetic wake, and assist in further promoting the development of the submersible non-acoustic detection.