Numerical evaluation of hydraulic performance of a laboratory-scale Archimedes screw pump

Archimedes screw pump (ASP) is a type of positive displacement pump for transporting water from lower to upper incline elevations. It is a simple and robust pump widely used for irrigation, flood mitigation, and in wastewater treatment plants. Although ASPs have been used for centuries, there is a lack of literature related to the optimal hydraulic performance and elucidating the underlying flow mechanisms. This study focuses on numerically evaluating ASP hydraulic performance across various rotational speeds and inclination angles. Experiments have also been performed on a laboratory-scale ASP with three flights, a length of 1500 mm, and an outer diameter of 300 mm for CFD validation. A computational fluid dynamics (CFD) model was developed to replicate the experimental setup, performed using the k-ε turbulence model with sliding mesh and the volume of fluid (VOF) method, which is suitable for liquid flow modeling involving combined free surface flow and rotational motion. The CFD model of ASP was simulated under various rotational speeds (25, 50, 75, and 100 rpm) and inclination angles (20°, 25°, and 30°). The results showed that flow rate and torque increase when rotational speed increases for all inclination angles. A maximum efficiency of 94.4% was obtained at 50 rpm and an inclination angle of 30°. These findings provide a useful reference for identifying optimal hydraulic performance of ASP using a CFD-based framework.