Numerical Prediction and Verification of Noise Radiation Characteristics of Diesel Engine Block 2019-01-1591

To assess contribution of structure-borne noise from the engine, it is critical to characterize dynamic and vibro-acoustic properties of the engine components and assembly. In this paper, a component level study of a three-cylinder diesel engine block is presented. Virtual analysis was done to predict natural frequencies and mode shapes of the engine block at the first step. Then, these results were used to decide the optimum test location and an experimental modal test was conducted on the engine block. The initial virtual model was correlated with test using natural frequencies and mode shapes. Then, the virtual model was updated with damping derived from experimental modal test to match vibration frequency response functions. Further, the virtual model was used for prediction of vibro-acoustic transfer functions. The vibro-acoustic transfer functions were also obtained from test. The results of transfer function were correlated with test. In future, we plan to use this approach for prediction of vibration and vibro-acoustic transfer functions for sub-assembly and eventually entire engine assembly to be able to use the models to predict the structure-borne noise from the engine.