Study On Characteristic Of Shallow Water Flow

The countries with long coastline, broad shallow rivers, shallow seas, and tidelands shallow water belt have the important comprehensive development value. The silt deposition process in these regions i.e., deposition shape and flow characteristic, the ecological environment, the land utilization, the route management and so on has the important influence. This laboratory study is primary pillars in studies for nearby the shallow water region and downriver water flow state of motion. The study of sediment deposition provides the scientific approaches and basic rules for the shallow water area's development. The main features of the study are given one by one below:1st, testing method researchConstruction of special model width ripple flume well equipped, with advanced and automatic metering equipments. Use of thread lining to produce different kinds of bed resistance testing method enabled the coefficient of friction range variation 5 times the actual bed resistance. The experiments conducted by this system provide the basic guarantee for the problems in the massive shallow recalculating flow, mentioned above.2nd, clear shallow water experimentRelationships between main parameters like bed resistance, the fluent intensity and placing thread lining at different distances are derived by regression method. Placing thread linings closely produces the bed resistance higher. The S number is directly proportional to the coefficient of friction, Also the S number as well as coefficient of friction is inversely proportion to the water depth. The recirculation length is directly proportional to the abutment width, and inversely proportional to the coefficient of friction. If bed resistance is higher recirculation area falls shorter. Among the variables like equivalent roughness, friction coefficient, S number and recirculation flow length variation rules has been discovered and regressive formula are established. These formulas perfectly described the shallow water flow rules and provide the fundamental knowledge.3rd, silt deposition experimental achievement.A. When the fluent intensity is weaker, the silt mainly deposit in the mainstream of recirculation flow region. Medium flow has capacity to create two recirculation regions deposition and in case of higher flows silt mainly deposit in two recirculation flow regions and form two separate deposit bodies.B. In the regions where flow velocity vector is less than 0.1m/s and vortices intensities less than 1(1/s) silt deposition take place.C. The silt deposition depth is approximately 0.3 times the water depth. The sediment depositions not only depend on coefficient of bed resistance friction but also on variation in S number and Re number. The silt deposit area and deposit volume increase with increase in bed resistance and the S number. The silt deposition area and deposition volume increase while Re number decrease.