Overview: The control of particlate flows is of great practical importance in the gas processing sector. The formation and accumulation of black powder in pipelines, for example, may be very harmful for hydrocarbon transportation installations, e.g. valves and metering installations. In general, solid particles affect the flow performance of gas pipelines and may lead to severe corrosion and degradation of the pipe integrity. Similarly, promising oil extraction techniques such as hydraulic fracturing involve transporting sand, into rock fractures to keep them open and facilitate oil flow.
The challenge: Gas processing and transport operators are indeed heavily investing in computer-based predictive strategies to anticipate hypothetical black-powder slug formation and develop fast and efficient removal techniques to operate in time. Of interest is to determine the effects of varying different operational parameters on the critical mass flow rate of gas that can evacuate a bed of particles to avoid slug formation, and wash out the pipes.
TransAT Solution: Because of the strong interactions between the fluid carrier phase and the solid particles, be it black powder or sand, advanced numerical methods are often needed for this class of flows: Lagrangian particle tracking including four-way coupling instead of average Euler-Euler formulations, Large-Eddy Simulation (LES) or V-LES instead of RANS, and transient rather than steady-state simulations. The models should account for the complete physical mechanisms in play, including particle-fluid/turbulence interactions, particle-wall-particle interactions, particle settling and packing, concentration effects, agglomeration, etc. All model ingredients are present in TransAT 5.1.1.