This study aims to analyze water flow through a centrifugal pump with straight radial blades double-acting impeller using computational fluid dynamics (CFD). The impeller analyzed was designed with the following conditions: a volume flow rate of 33.5 m3/h, head of 100 m, rotational speed of 2,950 rpm, and specific speed of 9. The first stage began with calculations for various dimensions of double-acting isolated impeller and impeller-collector assembly, followed by three-dimensional drawing and domain specification. In the second stage, grids for the isolated impeller and impellercollector assembly were generated. In the third stage, the initial conditions and boundary conditions were specified. Finally, the water flow through the isolated impeller and impeller-collector assembly was analyzed using the CFX 13 code to predict the water flow state. A fluid dynamic analysis of the isolated impeller and impeller-collector assembly reveals that the Q-H curve rises continuously toward shutoff as the flow rate is reduced. The results indicate that the total head rise of the isolated impeller is approximately 98.8 m for a 65 mm impeller inlet width and 99.89 m for a 70 mm impeller inlet width. This may be due to reduced circulation between blade passages of impeller. Similar to the isolated impeller, the Q-H curve of the impeller-collector assembly also rises continuously toward shutoff as the flow rate is reduced. The total head rise is reduced to approximately 98 m because of losses in the collector. Concerning the flow in the impeller-collector assembly when Q / Q design is or less than 1.0, the pressure distribution is high at the tongue of collector. Concerning the velocity distribution when Q / Q design is more or less than 1.0, there is circulation or a vortex at the top of the collector.
KAEWNAI, SUTHEP and Wongwises, Somchai
"ANALYSIS OF FLOW THROUGH A DOUBLE-ACTING IMPELLER WITH A STRAIGHT RADIAL BLADES USING CFD,"
International Journal of Applied Research in Mechanical Engineering: Vol. 2:
4, Article 7.
Available at: https://www.interscience.in/ijarme/vol2/iss4/7