Computational Fluid Dynamics Modeling of a Commercial Diving Incident

Abstract

A commercial diver using surface-supplied air was “jetting” a trench, which was using high-pressure water via an industrial “jetting hose” connected to a pressure-compensated tool to cut trenches in silty sea bottoms. This tool used high-pressure water pumped from the tender boat down to the diver. It was reported that man-made objects in the area cut the jetting hose, resulting in uncontrolled diver movement and subsequent injury. There were no direct witnesses available. The subsequent forensic engineering investigation used traditional calculations, laboratory testing, ergonomics, biomechanics, and computational fluid dynamics (CFDs) to determine the limits of the physics involved in order to assess the feasibility of the reported scenario. Specifically, CFD modeled the mass flow exiting the tool’s two ends and the cut in the hose as well as modeled the diver’s flow resistance while propelled through the water. The results indicated the applicable physics precluded the events as described.