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Atmospheric effects on the risetime and waveshape of sonic booms
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Bass, Henry E. Boulanger, Patrice Raspet, Richard |
| Copyright Year | 1994 |
| Description | Accurate prediction of human response to sonic booms from proposed HSCT aircraft depends on a knowledge of the waveshape and risetime of the boom at the ground. In previous work, we have developed a numerical technique to predict the combined effects of molecular absorption and finite wave distortion on the sonic boom as it propagates from the aircraft to the top of the turbulent boundary layer. We have more recently developed a scattering center based model to calculate the effects of turbulence on the sonic boom waveform as it propagates through this boundary layer. Calculations have been performed using single scales of turbulence and compared to measurements at Edwards AFB in the late 1960's. A model of the atmosphere involving two scales each for convective and mechanical turbulence has been developed and fit to meteorological data collected during JAPE 2. Scattering calculations employing this model underpredict the number of unperturbed waveforms. In order to develop a more realistic model of the atmosphere, the JAPE 2 meteorological data has been fit to a von Karman spectrum. Results of scattering using this multi-scale model will be presented. The combination of finite wave effects with turbulent scattering predictions includes the principal effects of the atmosphere on the sonic boom from the HSCT. |
| File Size | 696801 |
| Page Count | 14 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19950008472 |
| Archival Resource Key | ark:/13960/t7hq8vw71 |
| Language | English |
| Publisher Date | 1994-10-01 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Wave Diffraction Atmospheric Effects Atmospheric Turbulence Meteorological Parameters Acoustic Scattering Turbulent Boundary Layer Waveforms Shock Wave Interaction Turbulence Effects Sonic Booms Supersonic Transports Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
