The Optimal Layout And Experimental Investigation Of Vitebsk Station Outlet Structure

The gate dam is built across the river,the flow over the gate is usually in a high speed and comparatively centralizing.The middle-low water head dams have a great variation in discharge during the flood season,the flow over the gate mostly are submerged discharge.When the discharge is large,flow over the gate have common characteristics:large discharge per unit width,low Froude number,easily produce the undulatory jump and low energy dissipation rate,so the discharge capacity,the energy dissipation and erosion control is the key to the dam design.This paper relies on the Vitebsk Gate Dam Hydro Project,studying the discharge capacity of the sluice,the hydraulic characteristics of the sluice when the gates are full-opening or partial-opening,the energy dissipation and erosion control of the downstream through the hydraulic model test.Some conclusions can be listed as follows:(1)The study of the discharge capacity:The measuring results are larger than that of designed under characteristic water levels;the comprehensive flow coefficient ranges from 0.425 to 0.430 when the water curve isn’t affected by the gate.(2)The study of the hydraulic characteristics in upstream and downstream:The flow pattern of upstream and downstream are pretty good and meet the requirements of design under each condition;the distribution of the velocity is reasonable along the upstream and downstream,the maximum velocity is less than 15m/s,which doesn’t reach the high-velocity;.and the pressure along the upstream and downstream changes gentle,and all the pressure values are positive.As a whole,the general layout,the layout and the type design of the discharge structure are basically reasonable.(3)The study of the energy dissipation and erosion control:The flow make the folded-slope jump over the gate under large flood,which completed on the slope of the stilling basin,and while in the flat bottom of stilling basin and apron,the flow will gradually adjust until the velocity distribution of flow is similar to the natural river finally,it is noteworthy that the discharge volume is too large.Under the frequent flood,the flow makes a fully dissipation of energy in the stilling basin.By comparison,the most unfavorable condition is the large discharge condition.The depth of the scour hole in each condition is shallow,it means that the stilling basin and the apron could meet the requirements of energy dissipation.(4)The study of the gate operation:The hydraulic characteristics of three-hole partial opening is the best,and the hydraulic characteristics of middle-hole partial opening is the worst;considering the economy of the gate operation,the sluice should open the left and right gate at the first,and then open the middle-hole gradually during the frequent flood.