Design and optimization of contra-rotating fans

Abstract

Axial contra-rotating fans can be one solution for compact, efficient, powerful air movement technology especially if the speed of each impeller can be controlled independently. No additional bladed stator is required. And this special fan concept has potential for better acoustic behavior. Nonetheless the design of contra-rotating fans is a challenging task since performance and acoustic depended on various geometric parameters as well as of their matching. Virtual methods including automatic optimization within the design process allow to create and to simulate a large number different designs in very short time at low cost compared to experimental investigations.