Detection of Structural Vibration-Induced Noises with Modal Analysis in Diesel Generators

Diesel generators are one of the most common used energy sources for maintaining the continuity of electrical energy. Diesel generators cause high noises during their operation. There are many methods of eliminating the noise problems that diesel generators generate during energy production. However, these methods show differences according to the type of noise source. In this study, the problem of noise was emphasized that it is caused by structural vibrations of diesel generators. Therefore, the method of coherence function, which is an analytical method, was used for the detection of noise caused by structural vibrations. A test software and user interface was developed to perform sound and vibration measurement and analysis with using coherence function. The coherence analysis of sound and vibration data was made by performing various tests and measurements with the developed test software. In the coherence tests of diesel generator, the vibration frequencies that cause high noise at the measurement points were determined. In order to verify the coherence tests, the computer-aided 3D solid model of diesel generator used in the tests was created. Computer-aided modal analysis of the diesel generator was performed by using this model. The modal analysis was performed at the vibration measurement points and the frequencies that cause high noise. Coherence test results and modal analysis results were compared. It was seen that the results of the coherence measurement and the results of the computer-aided modal analysis supported each other. As a result of these studies, it was shown by computer-aided modal analysis that the high noise occurring in diesel generators can be determined by the coherence tests.  Cite this article as: Olmez U, Bayhan N, Dogan H, Uysal M. Detection of Structural Vibration-Induced Noises with Modal Analysis in Diesel Generators. Electrica, 2019; 19(1): 72-84.