Release Time:2019-03-09  Hits:

Indexed by: Journal Article

Date of Publication: 2014-10-01

Journal: OCEAN ENGINEERING

Included Journals: Scopus、EI、SCIE

Volume: 89

Page Number: 134-145

ISSN: 0029-8018

Key Words: Non-hydrostatic model; Boundary-fitted coordinate; Nonlinear waves; Focusing waves; Freak wave

Abstract: This paper employs a three-dimensional (3D) non-hydrostatic model to simulate nonlinear focusing wave groups. The non-hydrostatic model utilizes an explicit projection method to solve the Navier-Stokes equations. To accurately simulate the steep free surface involved in focusing waves, the model is built upon a general boundary-fitted coordinate system. This grid system allows for a great adaptability of the vertical discretization and meanwhile maintains the boundary-fitted properties of better fitting the bed and free surface. The advantage of the general boundary-fitted model is first validated by two test cases of nonlinear waves, Including nonlinear standing waves and two-dimensional (2D) focusing freak wave. Then, the model is applied to simulate 20 focusing waves in deep and intermediate-water depths and 3D focusing waves in deep-water depth. By comparing with experimental data, the model results well reproduce the main characteristics of 2D deep-water focusing waves and 2D intermediate-water focusing waves as well as 3D deep-water focusing waves, demonstrating the model's capability to resolve 2D or 3D focusing wave groups. Furthermore, in the test of 20 intermediate-water focusing waves, the downstream shifting of the focusing position and time is also studied numerically, which is not presented in the experiments. (C) 2014 Elsevier Ltd. All rights reserved.