The Research On Resistance Characteristic And Sensitivity Analysis Of Cutter Suction Dredger Pipeline

The cutter-suction dredger is widely used in dredging,whose transport pipeline length can reach tens of kilometers.The loss of resistance in the process of mud pipeline transportation affects the selection of power equipment and effective operation.There are many factors influencing the loss of pipeline transportation resistance.In order to reduce the resistance loss of long-distance pipeline transportation and improve the transportation efficiency,we need to study the resistance characteristics of major influence factors.Aiming at the problems such as high energy consumption,short transportation distance and easy obstruction which caused by high resistance loss in mud long distance pipeline transportation,combined with the actual construction conditions,this paper mainly to establish the model,parameter simulation,multi-factor sensitivity analysis based on orthogonal design,construction data comparison and so on.The specific research methods and conclusions are as follows:(1)Based on the pipeline parameters and construction conditions of actual ship,the physical model and mesh of pipeline were carried out by ICEM software.The parameters of study and boundary conditions were selected and then simulated in Fluent software.According to the results of Fluent simulation,the change rule of resistance loss under different influencing factors is obtained.When other influencing factors are constant,the loss of pipeline transportation increases with the increase of slurry velocity and concentration,pipe wall roughness,and shows a trend of linear growth.However,when the diameter of the particles gradually becomes larger,the loss of pipeline transmission resistance decreases gradually,and when the particle diameter is more than 0.4 mm,the resistance loss shows a trend of linear growth.(2)By using the method of orthogonal design to study factors for multi-factor sensitivity analysis.The influence degree of each factor on the pipeline mud transport resistance is as follows: mud flow rate> mud concentration> pipe wall roughness> particle diameter.Mud flow rate,mud concentration,wall roughness as the main influencing factors,particle diameter as a secondary factor.According to the regression coefficient,the linear regression equation between the main influencing factors and the loss of resistance is obtained.(3)Firstly,the real ship test plan is determined,and then the pipeline parameters and dredging data are measured and collected.Then transportation pipeline is treated as the horizontal straight pipe.Finally,the loss of the ship and the calculated value of the simulation and three commonly used empirical resistance calculated models are compared and analyzed.The results show that when the flow rate and the concentration are low,the calculated value through linear regression equation is close to the calculated value of real ship data.With the increase of the concentration and the flow rate,the error between the two increases gradually.Based on the orthogonal design method,the linear regression equation is superior to the empirical formula model.It is feasible to study the resistance characteristics of long-distance pipeline by using the method of this study.The results provide important reference for the design of dredging pipeline and the selection of construction parameters.