Lighthill’s Analogy Applied to an Automotive Turbocharger Compressor
* Präsentierender Autor
Zusammenfassung:Due to improvements regarding electric engine injection, the noise generated by a combustion engine has been significantly decreased over the last years. Consequently, a major remaining noise source is the turbocharger. A direct numerical simulation resolving both the vortical flow structures and the propagating acoustic waves is computational too demanding. Therefore, a hybrid aeroacoustics method, considering Lightill’s analogy, is applied for coupling the flow and the acoustic field. In doing so, the compressible flow simulation is restricted to the relevant domain of the flow, where Lighthill’s source terms are computed and then propagated by the wave equation to the whole acoustic domain. Thereby, the influence of all three parts of Lighthill’s tensor are investigated: (1) the Reynolds stress term, (2) the excess term and the (3) viscosity term. The investigation will be performed both in time and frequency domain, and in addition their propagation via the wave equation will be analyzed.