Rotating machinery noise and vibration study

Abstract

A project has been set up and implemented at the School of Mechanical and Production Engineering for the study of rotating machinery noise and vibration. The aim of the project is to allow students to analyse the vibratory displacement, velocity and acceleration spectra when the machine is running at certain speeds, to compare and correlate the noise and vibration signals and to determine the characteristic frequencies of various rotating machine components.

This paper describes the experimental setup, the kind of results that have been obtained and the conclusions drawn. It is found that the frequency spectra for the machine running at 240 rev/min and 480 rev/min contain many characteristic component frequencies which centre at these two machine running frequencies. These are due to the unbalance and misalignment of the shaft. The frequency spectrum due to noise at the same machine frequencies did not produce identical spectrum as that due to vibration. However, it is observed that when the vibration level is increased, the noise level also increases.