Waves Breaking Offshore

The following work was used to simulate waves breaking offshore, the technique is known as dispersive focusing and was used by Longuet Higgins in 1974, where wave energy was focused longitudinally by linearly decreasing the wave maker frequency. This increases the velocity of the waves being generated which then leads to the dispersive focusing of the waves causing a breaker.

Fluent was used to simulate the 32 wave components that cause the breaker. The signal used in Fluent was a summation of 32 equal amplitude wave frequency components spaced uniformly between 1.1 Hz and 0.5 Hz.

 

In the following wavetank animations, a velocity gradient was imposed at the left fluid boundary. First, high frequency waves are created. Next, low frequency waves are created and allowed to "catch up" to the high frequency waves. The interaction between the two types of waves causes a breaking wave to occur. A spilling breaker occurs at approximately time = 14 seconds, at position x = 0 m.