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Damped windows for aircraft interior noise control
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Buehrle, Ralph D. Klos, Jacob Gibbs, Gary P. |
| Copyright Year | 2004 |
| Description | Windows are a significant path for structure-borne and air-borne noise transmission into aircraft. To improve the acoustical performance, damped windows were fabricated using two or three layers of plexiglas with transparent viscoelastic damping material sandwiched between the layers. In this paper, numerical and experimental results are used to evaluate the acoustic benefits of damped windows. Tests were performed in the Structural Acoustic Loads and Transmission Facility at NASA Langley Research Center to measure the transmission loss for diffuse acoustic excitation and radiated sound power for point force excitation. Comparisons between uniform and damped plexiglas windows showed increased transmission loss of 6 dB at the first natural frequency, 6 dB at coincidence, and 4.5 dB over a 50 to 4k Hz range. Radiated sound power was reduced up to 7 dB at the lower natural frequencies and 3.7 dB over a 1000 Hz bandwidth. Numerical models are presented for the prediction of radiated sound power for point force excitation and transmission loss for diffuse acoustic excitation. Radiated sound power and transmission loss predictions are in good agreement with experimental data. A parametric study is presented that evaluates the optimum configuration of the damped plexiglas windows for reducing the radiated sound power. |
| File Size | 1579536 |
| Page Count | 12 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20040086707 |
| Archival Resource Key | ark:/13960/t0sr3tx53 |
| Language | English |
| Publisher Date | 2004-01-01 |
| Access Restriction | Open |
| Subject Keyword | Aircraft Design, Testing And Performance Fabrication Acoustic Excitation Resonant Frequencies Sound Transmission Acoustic Fatigue Aircraft Noise Aircraft Compartments Polymethyl Methacrylate Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
