LAUSR

Abstract Wax and other precipitates deposit on the inner wall of the pipeline during the transportation of petroleum and its products. They greatly reduce the transportation efficiency and cause potential safety hazards. In the process of offshore oil production and transportation, it is easier to produce wax and precipitates because of the low temperature and high pressure, which causes more serious issues. The jet end is a key component of underwater intelligent pigging robot (UIPR) because performance of wax and precipitates removal highly depends on the high-speed flow generated by the jet end. In this paper, the influence of the structural parameters of the jet end on the downstream flow field is analyzed by using the simulation method of k-epsilon. The simulation results show that different internal surfaces of baffles will have a greater impact on the pressure, velocity and turbulent kinetic energy of the flow field, and the change of turbulent kinetic energy and velocity is more than 10%. The baffle with Witonzinsky curve is found to superior in increasing turbulence kinetic energy and pressure. In addition, an orifice in the disc of jet cylinder contributes to reduce the pressure near the jet end and the loss of turbulent kinetic energy.