Noise attenuation of pedestal fan by modifying blade profile design

Abstract

TIlis th esis investigates the reduction of aeroJ ynamic noise in a pedestal fan by modifying the blade pro fil e, dra\\ing inspiration from owl wing characteristics and incorporating trailing edge serrations. • The study involves experimental measurements of SOU Ill] pressure levels in an anecho ic chamber us ing a sound level meter and computational fluid dynamics (eFD) and Acoustic simulati ons to validate the results. TIle experimental setup involves testing the original fan blade confi guration to obta in base line sound pressure levels. Measurements are conJuctcd in an anechoic chamber to minimize ex tern a l noise interference. • Subsequently, CFD simulations are performed to predict the aerodynamic noise generated by the existing blade profile. TIle results of the simulations are compared with experimental data to va lidate the accuracy of the computational model. • Experimental measurements of sound pressure levels are then conducted for the modified blade profile in the anechoic chamber. It was observed experimentally that the sound pressure level was reduced by 4 dB compared to the original blade profile. This reduction in noise validates the effectiveness of the trailing edge serrations in reducing aerodynamic noise. Although CFD simulations were not conducted for the modified blade profile, the experimental results provide valuable insight into the noise reduction achieved through design modification. This research contributes to the understanding of aerodynamic noise reduction in pedestal fans and provides a practical approach to design modification for noise reduction while maintaining or improving fan performance. The val idated experimental data serve as a basis for future optimizations and design iterations in fan engineering. An anemometer is employed to measure the flow rate, providing insights into the airflow performance. It was observed that the trailing edge serrations not only contribute to noise reduction but also enhance airflow performance.