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Validation of an adaptive combustion instability control method for gas-turbine engines
| Content Provider | NASA Technical Reports Server (NTRS) |
|---|---|
| Author | Kopasakis, George Chang, Clarence T. DeLaat, John C. |
| Copyright Year | 2004 |
| Description | This paper describes ongoing testing of an adaptive control method to suppress high frequency thermo-acoustic instabilities like those found in lean-burning, low emission combustors that are being developed for future aircraft gas turbine engines. The method called Adaptive Sliding Phasor Averaged Control, was previously tested in an experimental rig designed to simulate a combustor with an instability of about 530 Hz. Results published earlier, and briefly presented here, demonstrated that this method was effective in suppressing the instability. Because this test rig did not exhibit a well pronounced instability, a question remained regarding the effectiveness of the control methodology when applied to a more coherent instability. To answer this question, a modified combustor rig was assembled at the NASA Glenn Research Center in Cleveland, Ohio. The modified rig exhibited a more coherent, higher amplitude instability, but at a lower frequency of about 315 Hz. Test results show that this control method successfully reduced the instability pressure of the lower frequency test rig. In addition, due to a certain phenomena discovered and reported earlier, the so called Intra-Harmonic Coupling, a dramatic suppression of the instability was achieved by focusing control on the second harmonic of the instability. These results and their implications are discussed, as well as a hypothesis describing the mechanism of intra-harmonic coupling. |
| File Size | 425491 |
| Page Count | 16 |
| File Format | |
| Alternate Webpage(s) | http://archive.org/details/NASA_NTRS_Archive_20040171931 |
| Archival Resource Key | ark:/13960/t3sv2jg8w |
| Language | English |
| Publisher Date | 2004-10-01 |
| Access Restriction | Open |
| Subject Keyword | Aeronautics (general) Thermal Instability Combustion Stability Pressure Oscillations Gas Turbine Engines Acoustic Instability Acoustic Frequencies Adaptive Control 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 |
