Numerical simulation of slugging of stagnant liquid at a V-shaped elbow in a pipeline

Numerical simulation of slugging of a stagnant liquid at a V-shaped elbow in a hilly-terrain pipeline is carried out using a three-dimensional two-fluid model. The free surface treatment for the interfacial area density is employed to describe the interaction between the phases. Comparisons with experimental data show that this numerical model is able to simulate slug development from static puddle. The onset of slugging is also predictable with reasonable accuracy. The mechanism of the onset of slugging is discussed based on the numerical predictions. The predictions make it clear that the pressure drop of gas flow at the V-shaped elbow induces the difference in the liquid level between upstream and downstream regions of the V-shaped elbow, which is the major trigger of the onset of slugging of stagnant liquid at the V-shaped elbow.