Wind-shielded Acoustic Sensor Asymmetric Housing
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Solution Overview
Problem
Acoustic sensors in windy environments face limitations due to wind-induced noise, particularly from disturbances caused by the sensor's aerodynamics and complex velocity and pressure fluctuations, with existing solutions offering only limited immunity and not being rugged enough for various applications.
Innovation Solution
A wind-shielded acoustic sensor with a microphone housing featuring an aerodynamic cross-section that redirects fluid flow, includes sound ports to capture and mix sound signals and wind-related pressure fluctuations, and has deformable regions to reduce wind noise through uncorrelated averaging, allowing for effective noise reduction.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Object-affected harmful factors
If conventional aerodynamic designs are used to reduce wind noise, then wind noise is reduced for a given wind direction, but performance is negated when winds alter their course
Solution Approach 1:
The windscreen is designed with asymmetric geometry featuring a rounded front surface and a flat rear surface, creating a asymmetric profile that performs optimally across multiple wind directions. This asymmetric shape allows the sensor to maintain low-noise performance regardless of whether wind approaches from the front, side, or rear, resolving the contradiction between directional optimization and adaptability.
Solution Approach 2:
The windscreen incorporates a rounded front surface that smoothly curves to guide wind flow around the sensor housing. This curved geometry prevents sharp edges that would create turbulence and noise, while the combination of the rounded front and flat rear creates an asymmetric profile that adapts to various wind directions, maintaining performance consistency.
2Object-affected harmful factors
If porous materials like open cell foam are used to reduce wind-induced noise, then some immunity to wind fluctuations is achieved, but the solution is not sufficiently rugged for many applications
Solution Approach 1:
The windscreen is constructed from a thin, flexible membrane material that can deform elastically in response to wind pressure fluctuations. This flexible shell design allows the structure to adapt to varying wind conditions without breaking or deforming permanently, providing both noise reduction through deformation and the ruggedness needed for field applications. The flexibility enables the membrane to return to its original shape after deformation, maintaining structural integrity.
Solution Approach 2:
The windscreen material is specifically selected for its elastic properties, where the deformation parameter changes in response to wind pressure. The material's elasticity allows it to dynamically adjust its shape based on wind conditions, providing noise reduction through controlled deformation while maintaining the structural ruggedness required for outdoor applications. The elastic parameter enables reversible deformation that protects the sensor without compromising strength.
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
The solution significantly reduces wind noise, enabling the detection of acoustic signals with improved immunity to wind-induced fluctuations, making it suitable for rugged applications in windy conditions.
Implementation Method 1
The acoustic sensor has a microphone housing that employs an aerodynamic cross-section operative to redirect the bulk fluid flow around the sensing elements while causing minimal disturbance to the fluid flow
Implementation Method 2
The housing includes sufficiently thin and pliable regions that will deform subject to wind. The deformation of the housing regions and the sound ports allow sounds, including the acoustic signals and wind-related, random-like pressure fluctuations, to transmit through the housing and enter the cavity enclosed by the housing
Implementation Method 3
The sound ports bring the detected signal and pressure fluctuations into a central mixing cavity, which serves to remove the random-like pressure fluctuations through a process of uncorrelated averaging and intensify the detected signal
Data Source
AI summary
A wind-shielded acoustic sensor, having a microphone and a housing of the microphone. The housing has a streamlined, continuous profile about a latitudinal axis and a longitudinal axis thereof, such that wind-induced noise can be reduced. A plurality of uniformly spaced sound ports are formed along a plurality of circumferences centered about a longitudinal axis thereof. At least one region of the housing is sufficiently thin and pliable such that deformation will occur while subjected to wind. Thereby, both acoustic signals and wind-related random-like pressure fluctuations are transmitted into the cavity enclosed by the housing.