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Investigation of dispersion-relation-preserving scheme and spectral analysis methods for acoustic waves
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Vanel, Florence O. Baysal, Oktay |
| Copyright Year | 1995 |
| Description | Important characteristics of the aeroacoustic wave propagation are mostly encoded in their dispersion relations. Hence, a computational aeroacoustic (CAA) algorithm, which reasonably preserves these relations, was investigated. It was derived using an optimization procedure to ensure, that the numerical derivatives preserved the wave number and angular frequency of the differential terms in the linearized, 2-D Euler equations. Then, simulations were performed to validate the scheme and a compatible set of discretized boundary conditions. The computational results were found to agree favorably with the exact solutions. The boundary conditions were transparent to the outgoing waves, except when the disturbance source was close to a boundary. The time-domain data generated by such CAA solutions were often intractable until their spectra was analyzed. Therefore, the relative merits of three different methods were included in the study. For simple, periodic waves, the periodogram method produced better estimates of the steep-sloped spectra than the Blackman-Tukey method. Also, for this problem, the Hanning window was more effective when used with the weighted-overlapped-segment-averaging and Blackman-Tukey methods gave better results than the periodogram method. Finally, it was demonstrated that the representation of time domain-data was significantly dependent on the particular spectral analysis method employed. |
| File Size | 143528 |
| Page Count | 1 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19960008582 |
| Archival Resource Key | ark:/13960/t6vx5905j |
| Language | English |
| Publisher Date | 1995-01-01 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Sound Waves Computational Fluid Dynamics Average Two Dimensional Models Boundary Conditions Spectral Methods Wave Dispersion Wave Propagation Algorithms Differential Equations Euler Equations of Motion Angular Distribution Linear Equations Discrete Functions Reliability Weighting Functions Aeroacoustics Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Technical Report |
