Experimental investigation on interactions between two monochromatic wave trains with different approaching directions

摘要

Interactions between two identical monochromatic wave trains with a relative approaching angle of 24° were experimentally investigated in a well-designed ’X’ configuration. Wave trains with different amplitudes and frequencies were generated. The results showed that the interactions were strongly dependent on both wave amplitudes and frequencies. The wave trains can approximately maintain its initial status after the interactions for waves with small initial steepness. However, for larger waves, the interactions were enhanced and the surfaces were significantly distorted, no longer two-dimensional after the encounter. During the interaction process, there was an obvious increase in wave height, reaching the maximum amplification about 1.55 times of the initial height at the middle of the interaction region. Furthermore, the images captured by highspeed cameras illustrated that two wave trains enter the interaction region at the same time and then merged together during the interaction process, resulting in increase of the wave amplitude. The combined wave crest was initially composed of two straight segments and gradually morphed into a straight segment from the plan view. Then, wave broke in the downstream part of the interaction region with a crescent pattern of the crest.