The Internal Flow Field and Overall Performance of a Centrifugal Fan Impeller: Experiment and Prediction

Abstract

Analytical and experimental procedures for determining the detailed internal flow behavior in the impeller of a centrifugal fan are presented. Predicted and measured values of both the detailed flow fields and overall performance of the impeller are shown to be in good agreement. The analytical procedures are based on a finite element method to predict the inviscid flow field, coupled to a semi-empirical determination of pressure losses in the impeller based on boundary layer calculations. The experimental work used to validate these predictions uses extensive surface pressure taps in the rotating impeller as well as information from inlet and discharge velocity traverses to determine overall performance. The purpose of this work is the development of accurate and reliable analytical tools for the design of air and gas moving equipment with improved performance and efficiency for the power utility market and heavy industrial applications.