Preliminary investigation of oil boom failure by critical accumulation

The use of a barrier in the form of a floating boom to contain an oil slick faces four modes of failure; they are: drainage failure, droplet entrainment, splash-over and critical accumulation. Drainage, entrainment, and splash-over failure are well known, but critical accumulation has only recently been identified by Delvigne (1985, 1989) from experiments at the Delft Hydraulics Laboratory. Delvigne describes critical accumulation as an unstable reduction of the oil slick to a small length resulting in the entire slick passing beneath the barrier independent of barrier draft. Failure occurs when a highly viscous oil is exposed to a relative oil-water flow whereby the shear stress at the oil-water interface deforms and contracts the slick. The commercially available code Fluent 4.3 has recently been obtained by researchers at the University of Calgary with the intention of studying the containment of highly viscous oils and in particular the failure mode of critical accumulation