파랑에 관계되는 해양표면 마찰력을 고려한 발해만에서 3차원 흐름 모델링

Abstract

A three dimensional current modeling for Bohai Sea with wave dependent surface wind stress is carried out in present work. The three dimensional coupled hydrodynamical-ecological model for Regional and Shelf Seas Coherens incorporating the influences of wave-current interactions is coupled with a third generation wave model swan taking into account time-varying currents in this paper. The effects of wave on current are applied in both surface wind drag coefficient and bottom drag coefficient. First, the wave dependent drag coefficient is incorporated into Coherens to account for wave dependent surface wind stress. In bottom layer, secondly, the formulation proposed by Signell et al. (1990) which is an adapted form of the theory originally developed by Grant and Madsen (1979) is included in Coherens to account for effects of the interaction between wave and current on bottom stress except accounting for the angle factor between wave propagation and the current in present work. In order to compare simulation results of case with wave dependent drag coefficient, the simulation with wind dependent drag coefficient (Large and Pond, 1981) is carried out in present work too. Generally, the values of time series of current velocity, water surface elevation and significant wave height gotten by both the simulation cases have a good agreement with observed data. However, there are some differences in surface elevations and current velocities between the two simulation cases and the differences are more obvious in current velocities than in surface elevations. The residual currents of Bohai sea are also gotten through harmonic analysis and the results show some common well-recognized situations of residual current generally. Therefore, the introduction of wave dependent drag coefficient into Coherens with being coupled with swan can generate ideal results in Bohai sea.