Numerical Assessment for Coastal Water Purification Utilizing a Tidal Jet System

J. Ocean Eng. Technol. 2006;20(4):58-63.

Park, Jong-Chun;

Dept. of Naval Architecture and Ocean Engineering, Pusan National University;

조석분류를 이용한 연안해역의 수질정화에 관한 수치적 평가

박종천;

부산대학교 조선해양공학과;

Keywords: Tidal-jet generator(TJG), Tidal jet, Opening ratio, Water purification

핵심용어: 조류제, 조석 분류, 개방률, 수질 정화

Abstract

When the costal zone surrounded by a breakwater has a narrow vertical opening, currents in the vicinity of a narrow entrance can result in a jet flow, coinciding with the tide. Such a Tidal-Jet Generator(TJG) can change the water mass distribution and transport processes in the domain of influence of the jet. Also, it can decrease the residual time of them. In the present study, the water purification utilizing tidal jets in the coastal zone over constant bathymetry are estimated numerically, using a finite-difference numerical scheme, named the NS-MAC-TIDE method, which isbased on the fully 3D Navier-stokes(NS) equations. The shear velocity near the inlet of the TJG are predicted from the flow field simulation, and are assessed qualitatively with the development of scouring or sediment that is caused by the change of diffusion or sweeping flowup from the seabed of sediment particles. Finally, through solving a transport equation of concentration, the residual time related on mass transport processes and the flushing mechanism for water purification are investigated.