| Summary: | 碩士 === 中華大學 === 機械與航太工程研究所 === 93 === In this study, a thrust-vectoring micro jet engine was analyzed and the horizontal pendulum response was used to validate the engine model. The critical oscillation angle and time delay to the stable operation were used to determine the optimal combination of PID parameters. The proportional controller of 2, integration controller of 1.5, and derivative controller of 1.5 were used to the current system. The critical oscillation angle of 1.8°, steady-state error of 0.05°, and oscillation period of 0.56sec was found in the test. The results are very close to the numerical simulation. Where the critical oscillation angle of 1.7°, steady-state error of 0°and oscillation period of 0.6sec. The current system provides a minimal oscillation angle of 1.6°for, vectoring angle setting at 5°. Smaller than 3°setting angle of the thrust-vectoring nozzle, the pendulum system can not converge. Wider the setting angle of the thrust-vectoring nozzle, the system can converge at various location of the engine. Smaller the setting angle of the thrust-vectoring nozzle, the system can converge at a very narrow location of the engine. A low speed wind tunnel was used to study the parameters that affect the bandwidth of the thrust-vectoring nozzle. Namely the setting angle of the thrust-vectoring nozzle, the length of the deflector , and the air speed of the nozzle. The performance of the nozzle showed that a smaller setting angle of the thrust-vectoring angle has a larger bandwidth. An optimal length for the deflector should be used to avoid a larger reverse flow in the nozzle. The air speed that match the dynamic motion of the deflector provide the highest bandwidth of the system.
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