Cavitation Performance Enhancement of a Centrifugal Pump Impeller Based on Taguchi's Orthogonal Optimization

Abstract

This study is related to the cavitation performance enhancement of a centrifugal pump impeller using the orthogonal method. Preventing cavitation is essential to maintain the long-term desired performance of the pumps and energy efficiency. It is considered that the main parameters affecting cavitation are the inlet blade and wrap angles. Furthermore, these angles are defined as optimization parameters at both the shroud and hub. The twisted structure of the vanes causes the mentioned angles to have different values on the hub and shroud surfaces. Two different orthogonal schemes have been established, and the results have been successfully validated against each other after verifying the numerical results with the experiments. By implementing the second orthogonal optimization with reduced parameter variation steps, additional enhancement in cavitation performance is attained. In order to assess the cavitation performance of the designs, two-phase and three-dimensional computational fluid dynamics simulations are carried out. Additionally, cavitation tests are conducted numerically by gradually decreasing the inlet pressure of the working fluid, as described in the literature. As a result, a significant cavitation performance enhancement is achieved with a 19.3% decrease in the cavitation number of the pump at its best efficiency point. The study is significant because it provides a detailed investigation of the inlet blade and wrap angles at both the hub and shroud of the pump. Shear stress transport k-omega turbulence and Zwart-Gerber-Belamri cavitation models are implemented within the numerical study.