System and method for suppression of unwanted noise in ground test facilities
AssigneeThe United States of America as represented by the Administrator of the National Aeronautics and Space Administration
InventorsKhairul B. M. Q. Zaman, Michelle M. Clem, Amy F. Fagan
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Abstract
Systems and methods for the suppression of unwanted noise from a jet discharging into a duct are disclosed herein. The unwanted noise may be in the form of excited duct modes or howl due to super resonance. A damper member is used to reduce acoustic velocity perturbations at the velocity anti-node, associated with the half-wave resonance of the duct, weakening the resonance condition and reducing the amplitudes of the spectral peaks.
Claims20
A system that suppresses unwanted noise and howl in a test facility comprising:
- jet engine exhaust created within an engine test facility;
- an airflow duct having an inlet to take in the jet engine exhaust and an outlet;
- a diffuser connected to the outlet for routing the jet engine exhaust from the engine test facility;
- and
- at least one damper member engaged with the airflow duct to suppress unwanted noise and howl created within the airflow duct.
A method for suppressing unwanted jet engine exhaust noise and howl in a test facility comprising:
- routing the jet engine exhaust through an airflow duct having an inlet and an outlet;
- routing the jet engine exhaust from the outlet to a diffuser;
- and
- engaging at least one damper member with the airflow duct, wherein the at least one damper member suppresses a portion of the jet engine exhaust noise and howl.
Dependencies are inferred from the claim text.