OPERTATING AND ACOUSTIC CHARACTERISTICS OF CENTRIFUGAL FANS WITH INCLINED BLADES

Abstract

Considering the large use of fans today for various purposes, it is very important that the fans run in an economical operation regime. The economical operation of the fan implies high fan efficiency, above 90% of the maximum fan efficiency. The geometry of the fan impeller, particularly geometry of the fan blades, and also impeller dimensions, such as impeller width, affects the size of the flow area of the fan, and therefore operating characteristics of the fan. The optimal performance of a fan should also provide the best acoustic characteristics, which can be as important as its performance curves, and it can be a limiting factor for their application. However, the main issue is the impossibility of determining a more accurate estimation of the fan noise level during the fan designing process. With the development of CFD techniques it is now possible to determine fan performance curves and acoustic parameters, and to use numerical results in order to optimize its geometric parameters. In this analysis, the numerical investigation of three similar, but different centrifugal fans, which operate with a similar range of air flow rates, was performed using Ansys CFX 19.0. The obtained numerical results were analyzed in the paper.