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Shape optimization of pressure gradient microphones
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Norum, T. D. Seiner, J. M. |
| Copyright Year | 1977 |
| Description | Recently developed finite element computer programs were utilized to investigate the influence of the shape of a body on its scattering field with the aim of determining the optimal shape for a Pressure Gradient Microphone (PGM). Circular cylinders of various aspect ratios were evaluated to choose the length to diameter ratio best suited for a dual element PGM application. Alterations of the basic cylindrical shape by rounding the edges and recessing at the centerline were also studied. It was found that for a + or - 1 db deviation from a linear pressure gradient response, a circular cylinder of aspect ratio near 0.5 was most suitable, yielding a useful upper frequency corresponding to ka = 1.8. The maximum increase in this upper frequency limit obtained through a number of shape alterations was only about 20 percent. An initial experimental evaluation of a single element cylindrical PGM of aspect ratio 0.18 utilizing a piezoresistive type sensor was also performed and is compared to the analytical results. |
| File Size | 5699432 |
| Page Count | 28 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_19780005909 |
| Archival Resource Key | ark:/13960/t91883f7t |
| Language | English |
| Publisher Date | 1977-12-01 |
| Access Restriction | Open |
| Subject Keyword | Acoustics Electroacoustic Transducers Audio Equipment Electronic Equipment Optimization Microphones Pressure Gradients Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |