Impeller shape optimization considering start-up operation performance of mixed flow pump with semi-open casing

Mixed flow pumps play a crucial role in fluid transportation by integrating centrifugal and axial flow principles to achieve high flow rates and moderate head conditions. However, their efficiency and hydraulic stability can be compromised by challenges such as impeller blade misalignment, vortex formation, hump characteristics, and transient instabilities during start-up. One of the most effective ways to optimize pump performance is through the use of advanced computational techniques that refine impeller design, particularly blade angles, to enhance efficiency and suppress undesirable flow phenomena. Computational Fluid Dynamics (CFD), Response Surface Modeling (RSM), and Multi-Objective Genetic Algorithm (MOGA) are integrated to obtain the optimal impeller design. The optimal impeller design showed better performance and hump characteristics from start-up to design rotational speed.