Abstract：The RNG k-ε turbulence model and SIMPLEC algorithm are used to simulate the steady, three dimensional, internal flow field in a bulb tubular pump with up and downstream flow passages. Subsequently, the static stress in the impeller structure is analyzed numerically on ANSYS Workbench by means of sequential coupling method. The results show that the predicted performance curves of the pump are basically in agreement with the measurements. Additionally, the static pressure on the blade pressure side is higher than that on the suction side as a whole, and the low pressure appears on the blade leading edge near the impeller tip, where cavitation may be apt to occur. Impeller strength is mainly affected by centrifugal force and fluid pressure, also the peak equivalent stress and peak total displacement caused from both the centrifugal force and fluid pressure are far less than those generated by each of them. The peak equivalent stress rises with increasing flow rate, but the peak total displacement has one minimum at a flow rate. The peak equivalent stress occurs at the blade root near the blade trailing edge. The deformation of the impeller structure becomes more dominated with increasing radius, and the peak deformation appears on the blade tailing edge near the impeller tip. The results show that the impeller strength meets the requirement for operation. The presented results can provide a reference for analysis of stress characteristic of bulb tubular pump impeller.
