Effect Of Leading-edge Droop Nose And Trailing-edge Upward Nose On The Performance Of Multiphase Rotodynamic Pump

The effective exploitation of deep-sea oil and gas can guarantee China's energ y security supply also the main battlefield to increase oil and gas production in the future.The transportation technology of gas and liquid is one of the key technologies in the oil and gas exploitation and transportation field,whose core is the multiphase rotodynamic pump.The multiphase rotodynamic pump has been widely used because of its advantages of large transport flow and insensitivity to sand.But due to the density difference between the gas and liquid,the centrifugal force of the mixed medium under the rotation of the impeller is different,which leads to the separation of gas and liquid and even the blockage of the flow passage in the process of transportation.It seriously affects the hydraulic performance of the multiphase rotodynamic pump.A multiphase rotodynamic pump is taken as the research object.The Eulerian multiphase model and the RNG k-?turbulence model are used for numerical simulation of the multiphase rotodynamic pump.Firstly,in order to explore the separation of gas and liquid and the blockage of the multiphase rotodynamic pump,the base model was calculated in various working con ditions.On this basis,by referring to the lifting device of a wing flap,defining and adjusting the ratio of chord length l/l₀ and the deflection angle k to represent the variation law of airfoil modification parameters.The scheme of the leading-edge droop nose,trailing-edge upward nose and combined modification are designed for the impeller blade airfoil.And then,by comparing and analyzing the change rules of external characteristics and internal characteristics of the multiphase rotodynamic pump in different modification parameters conditions.Finally,the influence of airfoil mod ification on the performance of the multiphase rotodynamic pump was explored.The main research conclusions are as follows:(1)The leading-edge droop nose can effectively i mprove the pressurizatio n effect of the impeller inlet and reduce turbulent kinetic energy at the impeller inlet,which can also reduce energy dissipation and improve the transport performance of the multiphase rotodynamic pump.When the inlet gas volume fraction is 70%,the highest growth rate of the efficiency is 2.89%.(2)When the deflection angle of the airfoil leading-edge droop nose is constant,both head and efficiency increase first and then decrease with the increase of the ratio of chord length.There is the best ratio of chord length to make the efficiency of multiphase rotody namic pump best.(3)The trailing-edge upward nose can effectively improve the phenomenon of blockage and reduce turbulent kinetic energy at the impeller outlet,which can also reduce energy dissipation and improve the transport performance of the multipha se rotodynamic pump.When the inlet gas volume fraction is 70%,the highest growth rate of the efficiency is 3.04%.(4)When the deflection angle of the trailing-edge upward nose is constant,th e head decreases with the increase of the ratio of chord lengt h,and the efficiency increases first and then decreases.There is the most appropriate ratio of chord length to make the efficiency of multiphase rotodynamic pump best.(5)The similarities between the leading-edge droop nose and trailing-edg e upward nose are as follows:as the absolute deviation of the deflection angle decreases,the corresponding of the best chord length ratio increases,and the corresponding efficiency will first increase and then decrease.So there is a maximum efficiency.(6)The combined modification scheme can combine the respective advantages of the leading-edge droop nose and the modification design of trailing-edge upward nose.The improvement of efficiency is better than that of the leading-edge droop nose or the trailing-edge upward nose alone.The growth rate of the highest efficiency is 5.69%.