The Investigation On The Erosion Of Gas-liquid-solid Multiphase Flow In A Submarine Undulating Tube

With the highly exploited of marine oil and natural gas,the transportation of oil and gas using submarine pipeline has been a hot topic.The domestic and foreign researchers focus on the multiphase flow in continuous rolling pipe tube but the researches of complex flow with sand erosion in submarine undulating tube are relatively less.With the using of experiment' and numerical simulation method,the continuous rolling pipe with gas-liquid two-phase flow characteristics and pipe carrier erosion were investigated.First of all,based on a similar scale model,the experiment with the size of continuous rolling pipe model were designed.Pipe flow pattern were captured by a high-speed camera.The pressure of undulating tube rolling at the start of the first and second peaks were captured by pressure sensor.In this way,pressure changes and fluctuations at the end of tube 4 places were measured.The experiments consist of 30 groups through the analysis,the experimental groups can be divided into three patterns:Severe Slug Flow,hydrodynamic slug flow and transition flow.Continuous rolling pipe pressure of each point changes were influenced by tube fluid distribution,liquid flow rate.The greater the average pressure,the smaller the pressure fluctuation amplitude is.The fluid pressure decreases when liquid flows through monitoring point and the gas pressure increases when gas flows through monitoring point.Severe slug flow can be divided into four cycles during the experiment.According to experiment,rolling tube with gas-liquid two phase numerical simulation under experimental sizes were carried out.In order to get more comprehensive results of continuous rolling pipe type gas-liquid two phase flow patterns and flow distribution,Barnea flow pattern distribution are verified.In the up dip section continuous rolling pipe,intermittent flow was mainly presented and in downhill section of rolling tube,tratified flow was mainly presented.In addition,continuous rolling pipe tube under different gas-liquid two phase flow with sand erosion were also studied.The results showed that the erosion wear decreases firstly and increases with the increase of diameter of sand.