CFD Analysis and Design Effects in a Radial Pump Impeller

摘要

The direct flow analysis in hydraulic turbomachines using Computational Fluid Dynamic (CFD) methods can provide a quite illuminating picture of the developed flow field and its detailed characteristics. A numerical model for the simulation of the 3-dimensional turbulent flow in centrifugal pump impellers is developed in the present work, solving the Reynolds Averaged Navier Stokes equations with the control volume approach and on Cartesian grids. The latter can be constructed by a very fast and fully automated algorithm, whereas an effective numerical technique for solving the partially filled grid cells that are formed on the irregular boundaries of the computational domain is also incorporated. The computations for the steady flow field in a particular impeller are presented and analyzed, and the characteristic performance curves are constructed. The impeller geometry is represented by a number of controllable design variables, providing the capability of modifying the impeller shape and testing different configurations. This technique, combined with the automated grid generation algorithm facilitates the investigation and assessment of the effects of impeller design on its hydrodynamic behaviour. The results of such parametric studies conducted in the present work show that a remarkable gain in hydraulic efficiency may be achieved by optimizing the impeller geometry.