Study On Optimization Program Of Reef Explosion Of Fomiantan Based On Numerical Ship Model

After Three Gorges reservoir reaches 175 m,Fuling to Fengdu reach becomes a perennial backwater area,and the channel condition has been greatly improved.Due to the Fomiantan surface hindering reef in the reach out of the middle of the river,there is a strong cross flow and turbulence during the flood season,and the ship's safe navigation is threatened.In order to ensure the navigation safety of ships,at present,ships must take the crossing measure to avoid the disordered flow area in the reef section of river,which causes the intersect of the navigation routes and threatens the safety of the ship's navigation.Therefore,the research level of beach waterway navigation and reef formation scheme is very necessary,but also very urgent.Based on the measured data of terrain and hydrology in engineering reaches,this paper builds a two-dimensional mathematical model,and verifies water level,flow velocity and direction,and studies navigation hindering characteristics and the worst flow,and confirms renovation idea,parameters and scheme,and analyses the advantages and disadvantages of various schemes of Fomiantan respectively based on numerical simulation of water flow and ship handling.The main contents and results of this paper are as follows:(1)This paper use average water depth control volume method to build a two-dimensional mathematical model of Fomiantan based on the measured data of terrain and hydrology in engineering reaches,and verifies the model contrasting the simulation results with the measured data of water level,flow velocity and direction.The result indicate the model is applied to simulation of flow field in engineering reaches.(2)Based on the simulation calculation of the two-dimensional flow mathematical model,this paper chooses five indexes such as current speed,lateral velocity,lateral to vertical ratio of velocity,running resistance and thrust to drag ratio as the evaluated indexes of the research program and contrast the efficiency ratio of unit explosive depth to analyse the improvement of flow conditions by different explosive depth.(3)This paper selects eight groups of representative water level and flow combinations to develop the flow simulation under intensive conditions according to minimum design water level,submerged water level and water level of the worst flow,and analyses navigation hindering characteristics and formation cause in the engineeringreaches which is Fomiantan submerged forming underwater submerged dike in flood season,high velocity,steep gradients,right over ledge current,and great circumfluence strength after the beach.And this paper determines flow Q=24500m3/s as the worst flow.(4)This paper determines the depth,baseline and platform as renovation parameters,and determines the scheme which combine the depth optimization with the baseline and platform optimization,and contrast current speed,lateral velocity,lateral to vertical ratio of velocity,running resistance and thrust to drag ratio of different schemes,and recommend platform scheme 8&6.(5)This paper use ship-handling simulator to calculate navigation parameters such as the rudder angle,drift angle and speed of navigation,and analyses the effect of schemes,and finally determines platform scheme 8&6 as the optimal scheme.