Articles | Volume 19, issue 2
Nonlin. Processes Geophys., 19, 185–197, 2012

Special issue: Nonlinear waves in the ocean

Nonlin. Processes Geophys., 19, 185–197, 2012

Research article 16 Mar 2012

Research article | 16 Mar 2012

Particle trajectories beneath wave-current interaction in a two-dimensional field

Y.-Y. Chen3,1, H.-C. Hsu2, and H.-H. Hwung3 Y.-Y. Chen et al.
  • 1Dept. of Marine Environment and Eng., National Sun Yat-Sen Univ., Kaohsiung 804, Taiwan
  • 2Tainan Hydraulics Laboratory, National Cheng Kung Univ., Tainan 701, Taiwan
  • 3Dept. of Hydraulic and Ocean Eng., National Cheng Kung Univ., Tainan 701, Taiwan

Abstract. Within the Lagrangian reference framework we present a third-order trajectory solution for water particles in a two-dimensional wave-current interaction flow. The explicit parametric solution highlights the trajectory of a water particle and the wave kinematics above the mean water level and within a vertical water column, which were calculated previously by an approximation method using an Eulerian approach. Mass transport associated with a particle displacement can now be obtained directly in Lagrangian form without using the transformation from Eulerian to Lagrangian coordinates. In particular, the Lagrangian wave frequency and the Lagrangian mean level of particle motion can also be obtained, which are different from those in an Eulerian description. A series of laboratory experiments are performed to measure the trajectories of particles. By comparing the present asymptotic solution with laboratory experiments data, it is found that theoretical results show excellent agreement with experimental data. Moreover, the influence of a following current is found to increase the relative horizontal distance traveled by a water particle, while the converse is true in the case of an opposing current.