Pipeline Active Noise Control Engineering And Applied Research

Ducts not only deliver mass but transmite information, which play an important role in industries and agricultures. Duct noise almost exists every field and effects people's life. With increasing attention to the environmental problem, especially to the noise, active control of duct noise is becoming a very challenging research task. In this thesis, the design of the active control system and algorithm are studied systematically.Firstly, introduce the duct sound field including the factor influencing duct noise control. Based on the adaptive active noise control and its arithmetic, the basic theory and the system realization of the adaptive active duct noise control are introduced.Secondly, ground on the duct noise control, the Delayed-LMS algorithm, which is actulized easily, is brought forward, then the simulation on PC is achieved. It is shown from the computer simulation that for the single frequency noise, there will be a good effect when choosing the suitable parameters; but for the narrowband noise, the effect will become worse with increasement of the bandwidth. This result is helpful to analyze the parameters influencing ANC.Finally, the experimental research of the duct noise active control is accomplished. It is shown that the experimental results are in good agreement with the simulation results, which verifies the reliability of the active control of noise in duct.