Development of a Computational Fluid Dynamics Model for Archimedes Screw Pumps

Archimedes screw pumps (ASPs) have been used for land drainage, irrigation, and conveyance of mixed media for millennia. Due to their simple, robust design, modern ASPs are commonly used for land drainage and reclamation, as well as flood management and wastewater conveyance. In a climate-impacted future, the development of improved water management technologies is integral; however, design methods for ASPs are not well documented in the published literature. The design of screw pumps seems largely empirical. The leading text in screw pump design was compiled by Nagel in 1968, which predominantly sourced models and material from a Dutch paper by Muysken in 1932. The text uses many simplifications and empirical models based on undocumented experiments. So, there is a need to introduce more data and design insight to the literature to evaluate previous models and develop more in-depth models to predict screw pump performance more accurately. Gathering data from operating screw pumps can be difficult, particularly since characterizing a wide range of operating conditions and screw geometries is desired for modeling purposes; both are conditions that cannot be easily changed in an operating pumping station. So, a Computational Fluid Dynamic (CFD) model was developed to allow for simulation of any screw geometry or operating configuration. The model used OpenFOAM 8 to simulate the two-phase, immiscible flow of water and air through a dynamically mesh, full-scale Archimedes screw pump. A mesh-sensitivity study, and an evaluation study that compared simulated data to previously collected laboratory experiments, demonstrated that the simulation was an accurate approximation of screw pump performance. Once the model was deemed appropriate, it was used to collect data across a wide range of operating conditions and two scale-sized screw pumps.