(249f) Design of a Low Shear Hydrofoil through the Use of Computational Fluid Dynamics and Multi-Objective Design Optimization

Todays product development cycle requires even shorter turnaround times, and even lower costs. At the same time, quality should not suffer; on the contrary, companies need to improve their products in order to stay competitive. In many industries, the use of design optimization software is fast becoming the only way to achieve these apparently conflicting goals. The project of chemical processes and equipments is a task that demands a significant experimental support and a great number of prototypes and tests. Aiming at reducing the development time, ANSYS-CFX tools have been successfully coupled to modeFRONTIER so as to lead to the optimal design solution of a high efficiency impeller for low viscosity flow-controlled applications. The performance analysis of the impeller shape was performed with SST (Shear-Stress Transport) with streamline curvature turbulence model, combining advantages from k-e and k-w model, ensuring proper relation between turbulent stress and turbulent kinetic energy and allowing accurate and robust prediction of the impeller blade flow separation. Multiple Frames of Reference and the Frozen Rotor frame change model were used in order to investigate the rotor/stator interaction for the mixing vessel. A robust stochastic algorithm was used in the automatic multi-objective constrained shape design process that had 7 design variables, 2 nonlinear constraints, and 2 objectives. Simultaneous increases of the pumping and increases in the mixing homogeneity were achieved using this method.