Numerical simulation and experimental study of the influence of pump sump design parameters on vortex formation

The pump sump is a critical component of a pump station, and poor flow conditions often result in vortices that can adversely affect pump performance. This paper employs the shear-stress transport k–ω model to conduct numerical simulations of different dimensional schemes for open-type pump sump, and utilizes high-speed photography to visualize vortex morphologies. The study analyzes the flow field characteristics and vortex morphologies of each scheme, concluding that the velocity-weighted average angles at the bell mouth inlet and outlet cross section decrease as the bell mouth diameter increases. At a design flow rate of 35 L/s, the values of the inlet and outlet sections have decreased by 3.19° and 1.57° from scheme 1 to scheme 3, respectively. The swirl angle at the inlet cross section of the bell mouth is generally larger than that at the outlet. At a design flow rate of 35 L/s, the swirl angles at the inlet and outlet cross sections of the bell mouth in scheme 3 are 8.04° and 1.49° higher than those in scheme 1, respectively. Reducing the submergence depth to a certain extent can suppress the formation of suction vortices. Changes in sidewall distance have a minor effect on the formation of sidewall vortices. Reducing the clearance height increases the rotational intensity of floor-attached vortices, while reducing the backwall distance leads to uneven velocity distribution, making it easier for backwall vortices to form.