Wall Shear Stress and Differential Pressure in Large-Diameter Horizontal Multiphase Pipelines

Abstract

When a slug is formed a mixing vortex is created which contains pulses of bubbles which are shot toward the bottom of the pipe where they may impact and collapse. Bubble collapse creates high localized pressure, temperature, and wall shear stress, which cause a reduction in corrosion inhibitor efficiency. The average wall shear stress can be calculated using a conventional equation. However, using a conventional equation will not give the fluctuations in wall shear stress, which can be significant for slug flow conditions. Wall shear stress instruments are generally not accurate for fluids other than water, therefore, it would be beneficial to develop a relationship between the fluctuations in wall shear stress and the fluctuations in differential pressure. A differential pressure transducer, which can be used with any fluid, can be used to measure the fluctuations in differential pressure and then translate those values to fluctuations in wall shear stress. This study shows that wall shear stress fluctuations are related to differential pressure fluctuations to the 1.16 power. [S0195-0738(00)00604-X]