Noise Analysis of Small-size Pulse-jet Engine

Based on theoretical analysis of acoustic structure, the corresponding acoustic model of the pulse-jet engine was established. Pertinence measurement and near-field measurement were set up to test the noise. It was shown that the exhaust noise was the main noise-composition, secondly the intake noise. The combustion noise was much weaker. Simultaneously, the exhaust noise and intake noise had the one-way directivity property, namely that the noise intensity of exhaust noise, along the axial direction of exhaust tube, and the intake noise, along the axial direction of carburetor intake valve, were the highest. The noise intensity got weakened when the axial direction was offset. The more deflection angle, the more weakened. Especially it was outstanding on exhaust outlet. It was beneficial for the further study of low-noise pulse-jet engine.