Research Article
Investigation on Acoustic Properties of Thruster Chamber with Coaxial Injectors and Plenum Chamber
Table 4
Eigenfrequency, power amplitude, and damping rate of acoustic modes in the Model B chamber.
| | Length of the injector () | 0 | 2.2 | 3.2 | 4.4 | 6.2 | 7.8 | 10 |
| Resonator’s tuning frequency (, Hz) | — | 3750 | 2578 | 1875 | 1330 | 1057 | 825 | 1L acoustic mode | Eigenfrequency (Hz) | 985 | 944 | 853 | — | — | — | 1126 | Amplitude (kPa) | 0.76 | 1.1 | 1.1 | — | — | — | 0.58 | Damping factor | 11.8% | 11.2% | 17.3% | — | — | — | 11.5% | 2T acoustic mode | Eigenfrequency (Hz) | 3771 | 3777 | 3791 | 3798 | 3798 | 3842 | 3567 | Amplitude (kPa) | 1.17 | 0.72 | 1.1 | 1.15 | 0.31 | 0.57 | 1.18 | Damping factor | 3.4% | 3.5% | 2.5% | 2.1% | — | 3.5% | 2.1% | 1L2T acoustic mode | Eigenfrequency (Hz) | 3961 | 4155 | 4076 | 3988 | 4178 | 4049 | 4131 | Amplitude (kPa) | 0.58 | 1.1 | 1.65 | 0.65 | 0.8 | 0.89 | 0.61 | Damping factor | 8.2% | 2.4% | 2.4% | 3.2% | 4.3% | 2.0% | 3.4% | 2L2T acoustic mode | Eigenfrequency (Hz) | 4461 | 4626 | — | 4368 | 4558 | — | 4507 | Amplitude (kPa) | 0.31 | 0.8 | — | 0.33 | 0.49 | — | 0.44 | Damping factor | 3.2% | 3.7% | — | 1.9% | 4.6% | — | 2.0% | Unidentified frequency peak | Eigenfrequency (Hz) | — | — | — | — | 3323 | — | — | Amplitude (kPa) | — | — | — | — | 0.59 | — | — | Damping factor | — | — | — | — | 5.3% | — | — |
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