A NUMERICAL ANALYSIS OF TWO LAYER CURRENT OF FISHERY PORT WITH MANIFOLD CHANNEL

Abstract

Due to the rapid worldwide growth of international trade and commerce and to the fact that modern ships are larger, ports and harbors must therefore increase the depth of their fairways in order to maintain or enhance their economic competitiveness. This would definitely facilitate commercial and economic growth but the port activities are also likely to cause deterioration of air and marine water quality in the surrounding areas. A port can lead to severe pollution problem, over a large area due to the multifarious activities. Recently, as a concern of Eco-port is increased internationally, the improvement of water quality at the harbor or fishery port has gained increasing importance. Therefore, several methods have been studied to improve the water quality at the harbor or fishery port, and SEB (Seawater Exchange Breakwater) has been focused among these study. SEB is the structure established at the breakwater for exchanging the water of inside area with the seawater from outside. It, then, has greatly improved the water quality on the port where the SEB has been established (Han and Lee, 2006). But it has been shown a problem that the water on the inside area that is far from the SEB cannot be exchanged well, so that the water quality on that area has been still poor. In this study, to solve the problem of the SEB, Manifold channel, a new concept of SEB, is applied at the fishery port to exchange the water on the inside area. By using the manifold channels, it is possible to exchange the water on the inside area, where cannot be exchanged by the SEB, with the seawater from outside. In addition, it can be prevented partial eddies, which might be occurred by the SEB, by controlling gate conditions of manifold channels. To compare Manifold channel with previous SEB, a numerical model by two layer current of Jumunjin fishery port where the SEB has been established is carried out, and the computed results are compared with observed data to verify this model. Also, virtual manifold channels are assumed on Jumunjin fishery port, and the two layer current model is carried out under the same condition as the SEB. And then it is examined that Manifold channel has an advantage over the SEB for the water exchange on the inside area. The results of these comparisons are shown that Manifold channel has an advantage over the SEB for the water exchange on the inside area. Also, to examine the effect of gate conditions in Manifold channel, five cases of manifold channels are established on Jumunjin fishery port, and the two layer current model is carried out. From these results, the suitable outflow gate positions of the manifold channels are identified. In the future, the study on the detailed outflow gate positions will be continued, also, to improve the numerical analysis of the flow domain, this model will be developed as multi-layer current. Therefore, Manifold channel might be used broadly for the design of a breakwater to develop the facilities of port with waterfront area and water amenity.