CFD Analysis of Impeller Trimming

• Main Authors: Šlachtič Dušan, Knížat Branislav, Olšiak Róbert
• Format: Article
• Language: English
• Published: EDP Sciences 2020-01-01
• Series: MATEC Web of Conferences
• Online Access: https://www.matec-conferences.org/articles/matecconf/pdf/2020/24/matecconf_aenmfme2020_02009.pdf

Impeller trimming is a key impeller modification. It allows the best efficiency point (BEP) to be moved towards the region of lower flowrate and height, thus optimizing pump performance for specific piping systems. The paper deals with prediction of trimming results using CFD methods. Experience shows that modification of the BEP position depends on the trimming method as well as on the pump type and its specific speed. The analysed pump is of diagonal type with a specific speed of nb = 0.168. Its impeller is of a 4-blade design and a spiral casing is used as a volute. Seven cases of trimming are presented (including a non-trimmed original version). The paper compares CFD obtained data and data measured on an experimental stand. Additionally, the approach to CFD analysis, as well as the use of a turbulence model and characteristics of internal pump volume meshing are described.