Investigations of turbulent flows in a tubular pump and structural stresses of its impeller

Based on Navier-Stokes equations and RNG k-ε turbulence model, numerical simulation was carried out to investigate turbulent flows in tubular pumps and structural stresses of its impeller using commercial software of ANSYS Workbench. Firstly, the calculated velocity and pressure distributions in tubular pumps show that the whole flow pattern is uniform except for that in the region in the front of the pier in the discharge passage. The predicted spiral streamlines in the front of the discharge passage indicate that there exists an unrecovered velocity circulation. The computed reasonable distributions of the static pressure show the minimum happens at inlet edges on the suction surfaces of the blades which probably causes cavitations. One-way fluid-structure interaction method was then employed to make a further static structural analysis of the impeller, and the predicted stresses and deformations of the blades show that the maximal equivalent stress exists in the joint between the blades and the hub on pressure surfaces of the impeller, the maximum of total deformations of the blades increases as the radius increases. The maximal exists near the impeller rim at the inlet and outlet edges. The calculated results will provide references for further design and research of tubular pumps.