Observations of Cherenkov-Like Radial Wake in Water Waves.

Abstract

Cherenkov radiation (CR) is a fascinating phenomenon that occurs not only in electromagnetic (EM) waves but also in water waves. The V-shaped wake formed by a moving object on the water surface results from the constructive interference of water waves of different wavelengths, similar to CR. We designed and fabricated a one-dimensional (1D) water wave crystal to analogize the behavior of moving particles in water waves. This crystal exhibits a band structure with both positive (positive group velocity) and negative slopes (negative group velocity), exciting and directing the water waves to produce forward and backward radiating wakes through a mechanism similar to CR. Notably, the radiation angle is easily adjustable. This method of regulating water wave wakes holds potential applications in scattering cancellation-based wake stealth, navigation technology, and fluid dynamics for future offshore vessels.