Characteristic Of Flow Movement In Dredged Harbor Basins

There are many dredged harbor basins all over China, which occupy fewer shoreline resources as a notable characteristic, it also can develop new shorelines, and affect the river's flood of a certain degree. However, there exist varying degrees of silt upping, which hindered the promotion to a certain extent.The siltation relates with the circumfluence, it's movement characteristics are closely related to the siltation area and sedimentation form . So it is important to study the field of circumfluence, which provides a theoretical basis for the design of anti-siltation and sedimentation reduction measures, with great practical value.In this paper, the circumfluence range and surface velocity are calculated with mathematical models , and based on the physical model verification test data comparison , a method that to set back the scope of circumfluence is proposed by using the change process of water line .The study of dike against sand showed that: the main circumfluence will extend to river mainstream region behind the dike, leading to siltation exist in the mouth of the river and the river mainstream nearby . The length of circumfluence extent to the basin changes with angle of mainstream with the dike, and is same to the effective length of the dike .The circumfluence velocity of different import shapes is analysis based on boundary layer separation theory , it shows that the circumfluence strength will weaker while the import shapes similar to streamline .Based in the experimental research in dredged harbor basins, sum up the factors affecting the average flow rate of Cross section center velocity distribution of circulating flow, indicate the flow rate transverse distribution law obeying a power function scattering; Suggest that velocity distribution in transverse directions of Cross section center of circulating flow gradually changes from double curve distribution to line distribution, along transverse direction from inflow part to outflow part.