Experimental investigation on noise radiation characteristics of pulse detonation turbine engine

The noise radiation characteristics of two-phase pulse detonation combustor and pulse detonation turbine engine were investigated under different operating frequencies utilizing gasoline as fuel and air as oxidizer. The sound pressure data of noise radiation were presented for both single-pulse detonation combustor tube and pulse detonation turbine engine. The experimental results implied that the peak sound pressure level of PDTE exit with inner diameter being 60 mm was about 157 dB under the operating frequencies which varied from 5 Hz to 25 Hz, while the peak sound pressure level of single-pulse detonation combustor tube exit was about 170 dB under the same condition. The far-field jet-noise measurements of the pulse detonation turbine engine showed that radial turbine interacting with the pulse detonation combustor could decrease the peak sound pressure level of pulse detonation combustor with the maximum acoustic attenuation being approximately 14.2 dB for the current test conditions, which could be contributed to the energy extraction by the radial turbine from the pulse detonation combustor exhaust flow. The sound pressure level of both pulse detonation combustor and pulse detonation turbine engine exit was function of directivity angle from the exhaust centerline. In all the experiments, the equivalence ratio of gasoline/air mixture and the fill fraction were 1.2 and 1.0, respectively.