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Showing 1 to 4 of 4 for “"short duct"”.
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Development and Initial Evaluation of an Acoustic Apparatus Used For Testing of Farfield Noise Emitted by a Propeller in a Short Duct
… of acoustic emissions by a propeller in a short duct. An apparatus was designed based on a combination of acoustic principles and a desire to be able apply the knowledge gained to a practical application such as an ultralight aircraft in an effort to reduce the overall noise levels emitted. …
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Development of a compact sound source for the active control of turbofan inlet noise
… The sound source was fitted in an experimental duct representative of an aircraft engine inlet, and the interior and exterior sound pressure levels generated by the source were measured. The effects of excitation voltage, excitation frequency, duct length, and downstream termination of the duct …
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Compact Integrated Active-Passive Approach for Axial Fan Noise Control
… involved the installation of an axial fan into a short duct with both passive and active noise control functions. First, a systematic methodology for the analytical modeling of finite-length ducts with multiple discontinuities was formulated. The procedure involved the modeling of a duct as a …
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Active Control Of Noise Radiated From Personal Computers
… noise control technique based on folded lined ducts, integrating microphones and speakers, that were added to the PC air inlet and outlet. While the ducts were effective above 1000Hz, the use of a MIMO adaptive feedforward digital controller lead to significant noise reduction at the ducts …