Orbital Motion of Water Particles in Oscillatory Waves

The trajectory of a water particle in an oscillatory wave field has been studied by following the movement of the particle. The particle position at the end of each small time increment is calculated using the Eulerian velocity specifications. The results show the path of water particle is not a closed orbit and the calculated mass-transport velocity is in general agreement with Storkes formula. For the second-order waves, the present results demonstrate a much smaller mass-transport velocity than that predicted by the Storkes formula. In addition, the present study shows that a water particle does not return to the initial depth level at the end of each wave period. Instead, it moves in an oscillatory nature in the direction of wave propagation at a period much longer rate than the water waves.