Studies on the elbow corrosion associated with the wall-wetting process in stratified and wave flows

The flow-induced corrosion in gas-liquid flow usually occurs in the petrochemical and transportation industries, which has become a hot topic, especially for the elbow system. In this paper, a series of simulations using the VOF method and SST k-omega turbulence models were carried out to investigate the temporal and spatial distributions of the water wetting process in the elbow system. Combined with experiments, the relationship between the dynamic hydrophilic process and the corrosion mechanism was revealed. The results show that there is a stratified flow in the pipe at low speed. Wetness is always present in the inner wall of the elbow, and the corrosion rate reduces as the axial angle increases. As the velocity increases, the flow pattern changes to wave flow. Part of the water in the inner wall is entrained into the gas phase and thrown out onto the outer wall to form the water wetting. The location of maximum wall shear stress is transferred to outer wall, causing an increment of corrosion rate. The corrosion rate of the outer wall increases with the axial angle.