Abstract
In this paper a new methodology is presented for applying measured accelerations and forces as excitation on a structural finite element model in order to perform a forced frequency response analysis. The computed vibration constitutes the excitation for an acoustic boundary element analysis. The new developments presented in this paper are associated with: the equivalent force method that can prescribe the acceleration at certain parts of the structure; the integration within a single process of test data that define the excitation, with the vibration analysis, and the acoustic prediction; the utilization of the new technology in simulating the noise radiated from a running engine and determining the effects of design changes. Numerical results for noise radiated from a running engine are compared to test data for a baseline design. The effect of two structural design modifications on the radiated noise is computed, and conclusions are deduced.
Highlights
The objective of this work is to simulate numerically the noise radiated from a running engine, and identifyN
The computation of the structural vibration by the equivalent force method is integrated within an acoustic boundary element analysis process
Vibration test data, structural finite element analysis, and acoustic boundary element noise computations are combined into an integrated simulation process
Summary
The objective of this work is to simulate numerically the noise radiated from a running engine, and identify. N. Vlahopoulos et al / Development of an equivalent force method measurement locations when they are applied on the structural finite element model. The computation of the structural vibration by the equivalent force method is integrated within an acoustic boundary element analysis process. Vibration test data, structural finite element analysis, and acoustic boundary element noise computations are combined into an integrated simulation process. The equivalent force method computes the structural vibration based on: the normal modes and natural frequencies of the structure; the prescribed acceleration and pressure loads; and the structural damping. Since the equivalent force method is integrated within a noise prediction process, there is no need for an external transfer of data. The development, utilization, application, and validation of this approach to simulating the noise radiated from the block of an operating diesel engine are presented
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