Research On The Location Of On-line Measurement And The Impact Of Shipping In The South-to-North Water Transfer East Route Project In Provincial Section Of Jiangsu Province By CFD

The South-to-North Water Transfer Project in provincial section of Jiangsu Province is located in the central canal.It is an important metering section of the boundary of Sulu Province.The main task is to ensure the smooth flow of the eastern water conveyance corridor under the condition of meeting the requirements of flood discharge and navigation functions,the velocity of the provincial section varies greatly,which affects the measurement accuracy because of the engineering dispatching and navigation requirements.In this process,the layout of on-line flow monitoring section is the key to the efficiency and accuracy of on-line flow monitoring.The effective velocity data can not be obtained when the flow cross section and flow location are uncertain.It is very important to obtain the proper range of index velocity Because of the influence of effective ranging of navigation and current measuring equipment.Aiming at the problems existing in the South-to-North Water Transfer Project in provincial section of Jiangsu Province,In this paper,CFD research is carried out on the location of on-line measurement and the impact of shipping.Through investigation and data collection,the advantages and disadvantages of on-line flow monitoring methods for wide and shallow river channels are studied and analyzed,and the flow measurement methods suitable for the provincial section of the east route of the South-to-North Water Transfer Project are optimized;Through numerical simulation,the location of the on-line flow measurement section of the provincial section of the South-to-North Water Transfer Project is obtained.The velocity distribution in wide and shallow river channel is studied and analyzed,and the correlation of index velocity and flow is obtained.The influence of ships on river flow is studied.(1)The choice of on-line flow measurement method for provincial section.Rely on the research that about on-line monitoring method.It is analyzed and compared in the principle of the method,advantages and disadvantages of flow measurement and applicable conditions.Various kinds of the methods are analyzed the feasibility if can be used in the South-to-North Water Transfer Project in provincial Section of Jiangsu Province.The results show that HADCP is suitable for on-line flow monitoring at the provincial section of the east route of the South-to-North Water Transfer Project.(2)The choice of flow measurement section and position in provincial section and the correlation between index velocity and flow.The CFD technology was used to simulate river flow in provincial sections.The flow of the river channel in the provincial section was simulated to study the flow test position of the provincial section.Studies have shown that the velocity distribution is more uniform the flow pattern is better in section 4-4.It is suitable to be used as the flow measurement section.The flow rate is more stable within 2-3 meters of water depth,and the flow state is good,which is convenient for collecting valid data and suitable for installation of flow measuring equipment.The relationship between the selected index flow rate and the section flow rate is analyzed,and the index flow rate of the river section is obtained,which provides parameters for on-line measurement.The results show that the flow velocity in the range of 20-40m from the west bank of the flow measurement section of the river is relatively stable and the distribution is relatively uniform,and the flow correlation is good,which can be used as the index velocity of the on-line flow measurement.(3)The influence of ship navigation on flow measurement at provincial section.The influence of ship navigation on flow measurement is studied by CFD simulation.The influence of ship position,ship size,ship speed,the number of ships and ship driving direction on the flow measurement results at the provincial section was mainly studied.Changing the position of ships at the provincial section,it is found that when the ship is traveling in the area of 20m-40m from the west bank,the influence on the index velocity is the greatest.At this time,the river streamline is disordered,the velocity distribution is uneven,and the flow pattern is poor.Moreover,the farther away from the ship,the smaller the influence.When the ship is traveling in the area 70 meters away from the west bank,the influence on the velocity in the index velocity region is very small.Changing the ship speed,it is found that when the ship speed becomes larger,the flow velocity in the region within 20m-40m from the west bank is also larger than before,increasing from 0.18m/s to 0.20m/s.The research shows that the faster the ship speed,the greater the index velocity.Changing the ship size,it is found that when the volume of the ship doubles,vortices are likely to occur around the ship.As the volume increases,the vortex increases.At the same time,the influence on the index velocity becomes larger,and the flow velocity in the region within 20m-40m from the west bank is increased by about 0.01m/s.Changing the number of ships,it is found that when the number of ships increases to three,the flow velocity is affected by a wider range.The flow velocity in the region within 40m-60m from the west bank is uneven,and the flow velocity in the index velocity region is also larger than before.Changing the driving direction of ships and let the ship sail against the current.The result shows that the velocity around the bottom of the ship is larger than other positions,but the index velocity in the retrograde direction is about 0.01m/s lower than that in the downstream direction.Therefore,the influence of ship sail against the current on the index velocity is smaller than that of downstream flow.