A novel numerical method is applied to calculate radiation properties and sound transmission loss of periodic structures typical of an aircraft fuselage. The concept rests on that an accurate Statistical Energy Analysis (SEA) representation of the structure is determined from a small FE model consisting of one or a few cells of the periodic structure. The FE model can be kept small and computationally efficient, allowing for parametric studies of the effect of design changes. A typical aluminum aircraft panel is analyzed with the periodic concept, and the resulting sound transmission loss is found to correlate well to those measured. Furthermore, the concept has been extended to allow for turbulent boundary layer excitation and a numerical validation is presented where radiated sound powers are benchmarked to those from a full FE model. Finally, a parametric study is made, displaying the effects of frame spacing for diffuse and boundary layer excitation. The calculation results show that with boundary layer excitation a reduced frame spacing will increase sound radiation into the interior, predominantly in a mid-frequency regime, whereas for a diffuse field excitation a reduced frame spacing results in reduced radiation.
Analysis of sound transmission through aircraft fuselages excited by turbulent boundary layer or diffuse acoustic pressure fields
2009
9 Seiten, 6 Bilder, 1 Tabelle, 20 Quellen
Aufsatz (Konferenz)
Englisch
On Sound Transmission through Boundary Layers of Aircraft Fuselages and Engine Ducts
British Library Online Contents | 1996
|On Sound Transmission through Boundary Layers of Aircraft Fuselages and Engine Ducts
British Library Conference Proceedings | 1996
|