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Background oriented schlieren applied to study shock spacing in a screeching circular jet
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Zaman, Khairul B. M. Q. Clem, Michelle M. Fagan, Amy F. |
| Copyright Year | 2012 |
| Description | Background oriented schlieren (BOS) is a recent development of the schlieren and shadowgraph methods. The BOS technique has the ability to provide visualizations of the density gradient in both the axial and radial directions. The resultant magnitude of the density gradients allows for comparison with shadowgraph images. This paper first compares data obtained by the BOS and shadowgraph techniques at identical conditions in a free jet. The patterns and spacing of the shock trains obtained by the two techniques are found to be consistent with one another. This provides confidence in the shock spacing measurement by the BOS technique. Due to its simpler setup, BOS is then applied to investigate the shock spacing associated with the screech phenomenon, especially during stage jumps. Screech frequencies from a 37.6 mm convergent nozzle, as a function of jet Mach number (M(sub j)), are shown to exhibit various stages. As many as eight stages are identified with the present nozzle over the range 1.0 < M(sub j) <1.7. BOS images are acquired at various screech conditions and the shock spacing is examined as a function of M(sub j). |
| File Size | 1545800 |
| Page Count | 12 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20120003980 |
| Archival Resource Key | ark:/13960/t9s22zr85 |
| Language | English |
| Publisher Date | 2012-01-09 |
| Access Restriction | Open |
| Subject Keyword | Fluid Mechanics And Thermodynamics Free Jets Sound Waves Screech Tones Refraction Shadowgraph Photography Gradients Spacing Convergent Nozzles Ntrs Nasa Technical Reports Server (ntrs) Nasa Technical Reports Server Aerodynamics Aircraft Aerospace Engineering Aerospace Aeronautic Space Science |
| Content Type | Text |
| Resource Type | Article |
