Mojtaba Tahani - Faculty of New Sciences and Technologies, University of Teheran, Tehran, Iran
Vahid Pourheidari - Department of Mechanical Engineering, West Tehran Branch, Islamic Azad University, Tehran, Iran.

Centrifugal pumps are designed and tested by manufacturers in order to pumping water as operant fluid. However, in many cases these pumps are used to translate other fluids which they have higher viscosity than water. When a viscous fluid is pumped by a centrifugal pump, the performance is decreased in comparison to service with water. Many experimental investigations have been performed to study the effects of viscosity on the performance of centrifugal pump as well as the flow pattern through it. According to the high cost and required time for empirical studies, using computational fluid dynamic have been prevailed to predict the characteristics of oil centrifugal pump in last years. In this research study, numerical simulation has been used to study the influence of the fluid viscosity on the pump performance. In the steady state case, governing equations have been discretized and solved by implementation of finite volume method and high resolution algorithm, respectively. In addition, the k-ω SST model has been used to describe the turbulent flows. The pressure and velocity distributions on the impeller have been considered to analyze operational features of the oil centrifugal pump. In order to illustrate the negative impact of viscosity, the operational curves of pump have been plotted. In addition, the correction factors that are obtained from numerical solution have been compared with corresponding factors of American Hydraulic Institute.

Centrifugal pump, viscosity, turbulent flow, computational fluid dynamic, simulation, numerical modeling, correction factor