Abstract
The Rotating Cage is a standardized methodology for investigating the corrosion of metals under flowing conditions. As such, it can be used as a comparative method, for screening inhibitors or identifying the differences in the corrosion-inhibitory properties of different crude oils, as well as simulating flowing pipeline hydrodynamics. It is a complimentary technique to the rotating cylinder electrode and jet impingement method. Whilst it does not permit in situ measurements, it has a distinct advantage over other methods: whilst average corrosion rates are determined through mass loss, the relatively large surface area of the specimens permits statistical analysis of localized corrosion phenomena, monitored through techniques such as laser profilometry.
In this article, we seek to build upon earlier work, both experimental and theoretical, in order to better understand the fluid dynamics of the rotating cage method. Computational fluid dynamics (CFD) simulations were used to conduct a parametric study that investigated the dependence of the wall shear stress as a function of several variables, including: rotational velocity, temperature, fluid viscosity and density, for the standardized rotating cage test equipment. The wall shear stress is commonly used to relate experimental test conditions to flowing pipelines, thus the current study confirms the value of the rotating cage method in simulating pipeline flow.