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Indexed by:期刊论文

Date of Publication:2009-01-01

Journal:ACTA OCEANOLOGICA SINICA

Included Journals:SCIE、CSCD

Volume:28

Issue:6

Page Number:93-102

ISSN No.:0253-505X

Key Words:wave flume; wavelet transform; time ramp; wave instability; wavemaker

Abstract:This study investigates the initialization of nonlinear free-surface simulations in a numerical wave flume. Due to the mismatch between the linear input wavemaker motion and the kinematics of fully nonlinear waves, direct numerical simulations of progressive waves, generated by a sinusoidally moving wavemaker, are prone to suffering from high-frequency wave instability unless the flow is given sufficient time to adjust. A time ramp is superimposed on the wavemaker motion at the start that allows nonlinear free-surface simulations to be initialized with linear input. The duration of the ramp is adjusted to test its efficiency for short waves and long waves. Numerical results show that the time ramp scheme is effective to stabilize the wave instability at the start of the simulation in a wave flume.