Aircraft Rotor Noise Control via Phase Beamforming
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Solution Overview
Problem
Aircraft propellers, fans, and rotors generate significant acoustic radiation, leading to noise pollution and operational restrictions, with existing solutions failing to effectively manage this issue as a collective source of noise.
Innovation Solution
A system and method that utilize a central noise controller to regulate the frequency content and phase of rotor systems, employing beamforming techniques to control the directionality and acoustic behavior of the noise emitted, allowing for real-time tuning to reduce annoyance and detectability.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Power
If rotor systems operate at high power to generate thrust, then propulsion performance is improved, but acoustic radiation and noise pollution increase
Solution Approach 1:
The patent divides the rotor system into multiple independently controllable rotor units, each with adjustable frequency content and phase. This segmentation allows individual rotors to be tuned to create destructive interference patterns that cancel acoustic radiation while maintaining collective thrust generation.
Solution Approach 2:
The noise controller dynamically adjusts operational parameters including frequency content and phase of each rotor system based on commanded flight settings. By changing these parameters in real-time, the system optimizes the balance between thrust generation and acoustic radiation control.
2Object-generated harmful factors
If noise control measures are implemented to reduce acoustic radiation, then noise pollution is reduced, but device complexity increases
Solution Approach 1:
The noise controller serves multiple functions: it manages thrust generation, controls acoustic radiation, and adapts to different flight conditions all through a single integrated system. This multi-functionality reduces the need for separate dedicated noise control devices.
Solution Approach 2:
The system incorporates feedback mechanisms where the noise controller receives information about commanded flight settings and adjusts rotor operations accordingly. This feedback loop enables automatic noise control without requiring complex manual intervention or additional sensing infrastructure.
3Object-generated harmful factors
If individual rotor control is implemented to manage acoustic radiation, then directionality of noise is controlled, but control system complexity increases
Solution Approach 1:
The patent combines individual rotor control with aggregate noise management in a unified control approach. By merging the control of frequency content and phase across all rotors under a single noise controller, the system achieves directionality control without requiring separate complex control systems for each rotor.
Applied Scientific Principles
This section explains which scientific principles are used to turn an abstract innovation direction into a practical engineering solution.
Function Achieved in This Case
Effectively manages aggregate noise from rotor systems, reducing perceptibility and annoyance without compromising thrust, enabling aircraft to operate in noise-sensitive areas while maintaining primary flight functions.
Implementation Method 1
Aircraft propellers, fans, and rotors generate significant acoustic radiation
Implementation Method 2
employing beamforming techniques to control the directionality and acoustic behavior of the noise emitted
Data Source
Figure 1
Figure 2a~2b
Figure 2c
AI summary
Disclosed is a system for controlling acoustic radiation from an aircraft. The system comprising a plurality of rotor systems (one or more) and a noise controller configured to regulate acoustic radiation from the plurality of rotor systems. The noise controller can be configured to regulate a commanded flight setting from the flight control system and to output a regulated flight setting to the plurality of rotor systems. Based on the regulated flight setting, the plurality of rotor systems are configured to generate, individually and in aggregate, acoustic radiation having a target acoustic behavior. The target acoustic behavior may be achieved using beamforming techniques to, for example, change the directionality of acoustic radiation from the plurality of rotor systems, or otherwise tune the acoustic radiation to reduce detectability and/or annoyance.