Research On Hydraulic Characteristics Of Long-culvert Filling And Emptying System Of Shiplock During Filling Process

Long-culvert filling and emptying system of shiplock is a kind of simple longitudinal filling and emptying system,which is especially suitable for low-head and medium-head shiplocks.The shiplock chamber hydraulic characteristics are nearly related with ship mooring conditions in water delivery process.Currently,main ways of researching on flow conditions of shiplock during filling process are physical model and the prototype observation,3D numerical simulation is not mature and systematic.This paper exploits a new research direction of shiplock chamber hydraulic characteristics and promotes the development of shiplock hydraulics by 3D numerical simulation with long-culvert filling and emptying system shiplock.Physical model and mathematic model are combined to research velocity distribution and movement laws based on Second-line Shiplock of Mengzhouba.Generating mesh by Gambit Software,using RNG k-? model for turbulence flow,based on VOF method,achieving the valves' opening process by dynamic mesh technology,combined with VOF method,the 3D mathematic model in a whole concentrated filling and emptying system with 1:1 ratio were conducted to obtain detailed flow information during shiplock filling process.The results show that the laboratory data and the calculation results of mathematic models are in good agreement by contrast hydraulic indexes in shiplock chamber.Preliminary considering,3D numerical simulation is an effective research way for shiplock hydrodynamics.In the aspect of valves according to numerical simulation results: Counterclockwise whirlpool are discovered behind the valves in the whole opening process of valve.With the increase of valve opening ration,whirlpool become smaller and move upwards and top of the culvert.The whirlpool disappears when valve is fully opened.The trend of velocity,turbulent kinetic energy,turbulence dissipation rate increased first and then decreased in the valve section.There is no negative pressure around the valve section during the entire valve opening process.In the aspect of velocity field in shiplock chamber: At the beginning of the water filling,the water flows of side orifices from the upstream to the downstream in turn,at the same time,the velocity in the upstream section of the chamber is greater than the downstream section due to the effect of inertia.The trend of velocity increased first and then decreased in chamber and side orifices during the entire shiplock filling process.The flow condition of a single side orifice shows that with the increase of velocity,the oscillating end of the downstream side orifice is obviously larger than the upstream side orifice.Conclusions were drawn out by contrast models with baffle sills or without baffle sills: The overall velocity,maximum turbulent kinetic energy and turbulent dissipation rate of model with baffle sills in chamber is significantly less than the model without baffle sills at the same time because blocking function of baffle sills.Therefore,baffle sills play a good role in energy dissipation.Through the research of this thesis,a good foundation is established for the studying of other more complicated filling and emptying system and coupling of shiplock and water,besides,the development of shiplock hydraulics has been promoted.