Design of Centrifugal Fan with Flexible Blades to Extend the Effective Operating Range in Various Speeds and Mass Flows Based on Numerical Analysis and Statistical Computation

Abstract

This paper presents research on raising the efficiency and pressure of centrifugal fans at different speed ranges. This problem is related to the incompatibility of the fan characteristics with the speed conditions of the impeller and flow conditions of the installation when the centrifugal fans are operated, which decreases efficiency and raises energy consumption. In this research, a novel concept of regulating the blade parameters of centrifugal fans was given. The basis of this study is that a change in the blade angles and impeller outer diameter at different speeds significantly affects the power and the pressure rise of the fan. The scientific basis of this idea, which is using flexible blades for the fan, is aimed at providing high flow rates at relatively low running speeds, relatively low power requirements, and high efficiency when the fan operates in high-speed regions. Therefore, the design of the fan uses variable angles of the impeller blades by linking each blade to two springs. It enables adjustment to change the inlet and outlet blade angle of the impeller, which allows extending the range of operating parameters in accordance with the impeller speed. The flow simulation tests (CFD) of the novel method demonstrated the feasibility of adjusting the blade parameters and confirmed the benefits of this solution. The results of the research are given on the basis of the numerical analysis method and statistical computation method.

Keywords

• flexible fan blade
• adjustable fan blade
• centrifugal fan
• efficiency
• impeller