3-D Turbulent Flow Calculation Within A Centrifugal Pump Volute

The development of science and technology appeals to the improvement of fluid machinery's performance. Traditional design method is not enough to satisfy the need. It is necessary to adopt modern design theories and methods. First of all, designers will have to master its internal fluid characteristics.In this paper, 3-D turbulent flow in the centrifugal pump volute has been simulated. The results have exhibited the main flow phenomenon within a volute. The main work is outlined hereinafter:1. A brief description of the fluid machinery development, turbulence and Computational Fluid Dynamics (CFD) in the engineering is introduced.2. By using piecewise simulation, the physical grid generation of a volute is made. The volute is separated into three parts.3. By solving Possion equation, the automotive generation of 3-D Body-Fitted Coordinate (BFC) grid system is completed with its density controlled by the distribution functions P, Q, R.4. A transformation of governing equations in the Cartesian coordinate system to their counterparts in the random curvilinear coordinate system is performed. The discretion of equations is carried out with the Finite Volume Method (FVM). To eliminate pressure oscillations, variables are stored in a staggered grid system.5. On the basis of the SIMPLE algorithm, pressure-correction equation is derived to coupling the continuity equation and the momentum equations. The Gauss-Seidel line-by-line iterative method and the TDMA are applied to solving the discrete algebraic equations, and the relative error is utilized as the convergence criterion.6. The solving domain for a volute is determined and proper boundary conditions are introduced.7. A program to calculate the internal flow of a volute in th??main mentioned above is designed, and the calculating results are displayed visually.8. The results exhibit the main flow characteristics within the volute: Along the flow path of the volute, the flow velocity becomes smaller, and it diminishes evidently at the exit. When the discharge decreases, the pressure increases. From the thirteenth section to the thirty-third section, backflow appears near the outer wall of the volute; and it becomes more evident to the exit. On the thirty-ninth section, there is backflow on one side of the volute, and a uniform flow on the other. The simulation results shows good agreement with the experimental flow features in the volute, which validates the turbulent model used and solving process taken. The presented result provides a theoretical basis to the improvement of the hydraulic theory of volute design.