TRANSITION TO SLUG FLOW IN HORIZONTAL PIPES

The transition to slug flow in horizontal pipelines is reviewed. Experimental observations of the interface prior to slugging and of the effect of physical properties and pipe diameter on the transition are described. Theoretical progress in understanding the initiation of slugging through a stability analysis is summarized. Theories are classified by whether they invoke a long-wave assumption and whether they include viscous and nonlinear effects. Despite considerable progress, a general theory for predicting the initiation of slugging for arbitrary fluids in pipelines of varying size and pressure is far from being realized.