Analysis Of The Water Converying Characteristics In The Folio Arc Gate

The folio arc gate is often used in tidal river locks.It is composed of two fan-shaped gates rotating around the vertical axis.It can bear bidirectional water head and has the advantages of flexible opening and closing and fast speed,without limiting navigable clearance.The folio arc gate can directly use the door gap to carry water,but the outflow tends to deviate to one side,forming a folding water flow,washing the downstream bottom guard and shore wall.Therefore,it is necessary to study the flow characteristics of the water behind the gate of the folio arc gate and reduce the scouring of the bank slope and riverbed by the water flow through engineering measures.In this paper,by combining model test and numerical simulation,combined with the actual project,the water flow characteristics of the folio arc gate are analyzed.The main contents are as follows:The physical model of the gate was established,and the distribution of the flow field behind the gate under different working conditions was obtained by seeding tracer particles on the water surface and measuring by the current meter.The experimental results show that the outlet flow of the sluice under the condition of relatively small gate opening forms a deflated flow,which randomly shifts to both sides of the flume and presents different distribution patterns,and is greatly affected by upstream disturbance.Under the condition of large opening,the water flow stably deviates to one side,is not affected by upstream disturbance,and does not diffuse in the width direction of the tank.The numerical simulation of the flow field of the folio arc gate is carried out,and the calculated results agree with the experimental results.Numerical simulation of the flow field behind the gate of the Yiyang River gate project in Yangzhou shows that the relative maximum velocity decreases slowly.The larger the flow rate is,the closer the starting point of the deflection is to the downstream,and the smaller the deflection Angle is.The erosion of bank slope is more serious when the flow is large.Under different flow conditions,the water distribution pattern is similar,that is,the water first deviates to one side,then bends to the other side after flowing out of the wing wall and moves downstream.In order to make the gate outflow diffuse in the plane,adjust the velocity distribution,and reduce the erosion of the downstream slope,combined with the characteristics of jet flow diffusion under the plane opposite the folio arc gate,a rectification measure of wedge diversion pier+bottom slope+slope retaining was adopted.The influence of the width of diversion pier and the height of bottom barrier on the flow diffusion effect was analyzed and verified by experiments.The results show that the wedge diversion pier and bottom barrier have a good diffusion effect on the concentrated flow under the sluice,and the retaining barrier on the slope can effectively prevent the deflection scouring.The results of this paper have reference value for solving some problems in operation of the folio arc gate.