Characteristics of surface signature generated by an underwater sphere with regular free surface waves

The characteristics of the wake generated by an underwater sphere in the presence of regular free surface waves are investigated. Based on the spectral wave explicit Navier–Stokes equations decomposition strategy, the incident waves are prescribed based on spectral wave models, and the wake characteristics generated by the underwater sphere are determined using a computational fluid dynamics solver. The effects of the wavelength of the surface waves and the Froude number on the wake characteristics are investigated. The results show that the existence of free surface waves can distort the wake patterns, causing them to shift from the classical V-shaped Kelvin wake to an Ω-shape. Analysis of the spectrum indicates that the distortion of wake patterns is mainly determined by the wave–wave interactions.