Study on Quantitative Estimation of Seawater Quality in Harbor Using Wind-Powered Seawater Exchange System

Abstract

The seawater exchange breakwater (SEB) constructed at Jumunjin Harbor on Korea’s eastern coast is composed of a semicircular overtopping seawall on the north side of the offshore breakwater and single outlet through the breakwater (CASE 0). Additional counter-measures, CASE 1 and CASE 2, work to improve water quality in the harbor are examined here. A wind-powered seawater exchange system (WSES) including a transit pipeline with 781.9 meters in length and 1.5 meters in diameter is linked to 3 multi-outlets set along the berthing areas of the harbor. The WSES pumps up offshore seawater by a hydraulic pump operated from wind power. The outflow at each outlet for each case is calculated and compared with the existing case, CASE 0. When the actual discharge is 71,000m3/day, the coefficient of correlation is measured Cq=0.11. The seawater exchange rates in the harbor concerned three cases were computed using coupled flow and diffusion numerical modeling system. The numerical model results demonstrate that CASE 2 for the WSES with transit pipeline and multi-outlet are more effective than CASE 0 for the SEB with single outlet in spite of reduced influx rate due to long transit pipeline, and consequent increment of head loss.