Noise Computation of a Turbo-Engine Jet Exhaust Based on LES and Lighthill's Acoustic Analogy.

Författare: Mihaescu, M, Szasz, R.Z., Fuchs, L.F.
Dokumenttyp: Artikel
Tillstånd: Publicerad
Tidskrift: Proceedings of ASME Turbo Expo 2004.
Volym: 5   1723-1731
År: 2004


Increasing noise regulations at urban airports force jet engine manufactures to develop and build more quiet engines. Over recent years, a significant reduction in fan and mechanical noise has been achieved. However, the jet exhaust is the principal source of noise. The acoustical field that is generated by a turbo-engine jet exhaust running near the ground level is considered. The full equations of motion for compressible and unsteady flows describe both flow field and sound generation. The flow variables are decomposed into semi-compressible components and inviscid, irrotational acoustical components. The turbulent flow and mixing are computed using Large Eddy Simulation (LES). The radiated acoustical field is computed using the Lighthill's acoustic analogy with acoustic sources provided by instantaneous LES data.