Numerical simulation of a neutrally buoyant round jet in a wave environment

Yen-Lung Chen, Shih-Chun Hsiao, Yu-Cheng Hou, Han-Lun Wu, Yuan-Chieh Wu

Monday 29 june 2015

17:39 - 17:42h at Amazon (level 1)

Themes: (T) Water engineering, (ST) River and coastal engineering, Poster pitches

Parallel session: Poster pitch: 3C. Coastal Engineering

This paper aims to simulate a neutrally buoyant round jet discharged at the mid-depth in the opposite direction to the wave propagation using a three-dimensional numerical model named FLOW-3D. The present numerical model solves the Reynolds-averaged Navier-Stokes (RANS) equations combined with standard turbulence model, and the free surface deformation is tracked using volume of fluid method (VOF). The round jet is modelled by a horizontal pipe and mass source. The capability of numerical model simulating the round jet in a stagnant environment is firstly validated by an empirical formula. Comparisons between the empirical formula and present numerical results show good agreements. Then, a neutrally buoyant round jet in a wave environment is investigated. The decay of jet centerline velocity is compared with available experimental data. Finally, the variation of the jet cross-sectional profile under different wave height is discussed. The results show that the ratio of the jet vertical width (z-direction) to its horizontal width (y-direction) is insensitive to wave periods, but it increases in the potential core and decreases in the near field with the increase of the wave height.