Study On Mathematical Model Of Landscape And Water Transfer Project In Niujiaodian

In the irrigation area of the lower Yellow River,the water diversion method of the open channel is mostly adopted.With the development of the society,the open channel with simple shape can not meet the engineering needs.On the basis of ensuring the hard demand for irrigation and water transportation,the soft demand for environmental landscape combined with surrounding vegetation and topography is gradually expanding.This paper takes the Niujiaodian landscape and water transfer project as the research object,and studies the movement characteristics of the water flow,the variation of the water surface line and the movement of the sediment along in the multi-stage step water transfer open channel and the landscape parallel pipeline.The main contents and results are as follows:(1)Using the k-? turbulence model and the mixture model,the hydrodynamic model of multi-stage step water transfer open channel is established,and the distribution characteristics of flow velocity,pressure,water surface line and sediment deposition under different calculation conditions are studied.By comparing the different water levels and sediment concentration,it is found that the water flow in the open channel has a relatively stable flow pattern in the first step and the second half of the third step.The flow velocity,pressure and water surface line are in line with the movement law of the open channel.Among them,the second half of the third step is affected by the secondary picking flow,and the large flow velocity area is moved down.Affected by the two-stage flip bucket deflecting flow and dropping,the water flow is in the two-stage flip bucket position,the second step and the first half of the third step are not stable,the water line and the flow velocity vary greatly and form a obvious flushing on the bottom plate on the second step.Influenced by the barrier founction of the flip bucket and the intersection of the downstream water flow,the sediment is easily deposited on the front of the two-stage flip bucket and the third step.In order to ensure the safe operation of the channel,the silt should be cleaned up in time,and the protection of the second step floor should be strengthened.(2)The landscape pipeline was designed based on the physical parameters of the open channel,the《Technical specification for artificial fountain and water scenery engineering》and the requirements of the design department of the Niujiaodian.The hydraulic parameters of the inlet and outlet sections of the pipeline were calculated by using the continuity equation and the Bernoulli equation of the parallel pipeline.Based on this,the pipeline parameters were corrected and the hydraulic parameters of the modified pipeline section were obtained.(3)Using the k-? turbulence model and the mixture model,the hydrodynamic model of landscape pipeline is established,and the velocity distribution of the water flow in the pipeline under uncorrected,corrected and minimum control water levels are obtained.And compared with the hydraulic elements of the pipeline section calculated by Bernoulli equation,the error basically meets the allowable requirements.Based on the corrected pipeline parameters,the distribution of sediment in the pipeline was studied,and the position where sediment is readily deposited was obtained.