Investigation of Unsteady Flow in a Submersible Tubular Pumping System

To better understand the workings of submersible tubular pumping system and to enable future improvements, the pressure fluctuation and unsteady flow characteristics due to the complex rotor-stator interactions need to be properly delineated. High-frequency pressure measurements coupled with CFD simulations have been invoked in this study to elucidate the unsteady flow in different components of a submersible tubular pumping system at different discharges. The focus is on the impeller and guide vane, where the unsteady interaction is the strongest. The pressure pulsation distributions of different characteristic cross sections such as impeller exit, middle of guide vane, and exit of guide vane were quantified. In addition, the flow characteristics and the turbulent kinetic energy inside the impeller, guide vane, and bulb unit were obtained at the different time steps. The results show that the pressure pulsation frequency obtained by simulation was in agreement with the experimental results, including the critical points around the impeller and the guide vanes. The complementary two-prong approach is thus proven to be a powerful duo in researching and advancing a convoluted pumping system.