Wind Tunnel Acoustic Imaging and Noise Source Localization Solution
Overview
Wind tunnel customers are expanding beyond traditional measurements such as lift, drag, pressure, and flow-field analysis into aeroacoustic testing. They not only want to verify whether aerodynamic performance targets are met, but also understand where noise originates, which frequency bands dominate, which components contribute most, and whether design modifications truly reduce noise.
The SonoDAQ Low-Speed Wind Tunnel Acoustic Imaging Solution is designed for applications including automotive wind noise, UAV rotors, aerospace components, wind turbine blades, and ventilation equipment. It provides a complete workflow covering acoustic field acquisition, synchronized recording, spectral analysis, sound source localization, and report generation.
High-Precision Multi-Channel Synchronous Acquisition
Acoustic imaging with large microphone arrays places stringent requirements on channel consistency and phase coherence. SonoDAQ utilizes PTP (Precision Time Protocol) as a unified time reference, supporting synchronized multi-channel acquisition and multi-device expansion, ensuring that all acquisition channels are precisely aligned on the same time axis.
With synchronization accuracy better than 100 ns, the system provides a stable and reliable foundation for sound source localization, phase analysis, and array-based acoustic imaging.
Intuitive Acoustic Imaging and Source Localization
Unlike conventional wind tunnel testing, which focuses primarily on aerodynamic performance indicators such as lift, drag, and pressure distribution, this solution introduces acoustic imaging capabilities.
Noise sources are displayed as acoustic heat maps overlaid on live camera images, enabling engineers to visualize exactly where noise is generated. Users can quickly determine not only how loud the noise is, but also where it comes from.
This visualized localization approach improves troubleshooting efficiency and provides direct evidence for noise reduction, structural optimization, and design comparison studies.
Irregular Array Geometry
The system adopts an irregular microphone array layout, reducing the risk of spatial aliasing commonly associated with regular arrays. This design minimizes sidelobes and grating lobes that can negatively affect localization accuracy.
Compared with regular arrays, irregular configurations improve the distinguishability of the main lobe in acoustic maps, making primary noise sources easier to identify.
In complex low-speed wind tunnel acoustic environments, this design enhances the stability and reliability of sound source localization results, providing a stronger basis for subsequent noise analysis and optimization.
Synchronized Recording of Multiple Physical Quantities
The modular acquisition architecture supports flexible integration of various sensor types, including:
• Acoustic sensors
• Vibration sensors
• Wind speed sensors
• Rotational speed sensors
• Attitude angle sensors
• Temperature and humidity sensors
• Barometric pressure sensors
This enables synchronized acquisition and unified recording of acoustic signals together with wind tunnel operating conditions.
Each acoustic measurement can be directly associated with specific test conditions and operating parameters, facilitating result reproduction, multi-condition comparison, root-cause analysis, and optimization validation.
Wideband Acquisition with High Dynamic Range
The system supports a frequency range from 1 Hz to 100 kHz, covering applications ranging from low-frequency structural vibration measurements to high-frequency acoustic detail analysis.
Suitable applications include:
• Wind noise analysis
• Tonal noise and whistling detection
• Abnormal noise diagnostics
• Structural response testing
• High-bandwidth signal analysis
Leveraging a 32-bit ADC architecture combined with Quad-ADC Fusion Technology, the system achieves a dynamic range of up to 170 dB, enabling accurate capture of both extremely weak signals and high sound pressure level events within the same measurement platform.
OpenTest Integrated Analysis Software
OpenTest consolidates all major analysis functions within a single software environment, including:
• Real-time waveform monitoring
• FFT spectrum analysis
• 1/3-octave analysis
• SPL trend monitoring
• Sound source localization
• Acoustic heat map visualization
• Operating condition correlation
This integrated workflow helps engineers complete the entire process from monitoring and analysis to result interpretation.
The software also supports chart export and automated report generation, connecting data acquisition, acoustic imaging, analysis, and reporting into a unified engineering delivery workflow.
Scalable Platform Architecture
Phase 1: 24-48 Channels
Small-scale validation platform for verifying wind tunnel environments, array configurations, and initial acoustic imaging performance.
Phase 2: 64-128 Channels
Project-level deployment supporting routine testing activities, including spectral analysis, source localization, operating-condition comparisons, and report generation.
Phase 3: 256+ Channels
Large-scale acoustic imaging platform for institutional aeroacoustic testing capability development, enabling standardized workflows, templates, and test databases.
Typical 120-Channel Acoustic Imaging Configuration
A typical 120-channel system consists of:
• Measurement microphones
• Acoustic calibrator
• Custom array frame
• SonoDAQ Pro
• IED input modules
• OpenTest software
Together, these components form a complete platform covering calibration, acoustic acquisition, synchronized recording, sound source localization, and report generation.
The configuration is well suited for:
• Low-speed wind tunnel aeroacoustic testing
• Vehicle and component noise source localization
• Multi-condition comparative acoustic analysis
• Engineering validation and optimization studies
System Devices
CRY3203-S01 Free-Field Microphone Set, 1/2", 50mV/Pa
CRY5820 SonoDAQ Pro
CRY5011 IEPE Analog In - IED
CRY3018 Sound Calibrator
OpenTest
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Get in touch
If you are interested or have questions about our products, book a demo and we will be glad to show how it works, which solutions it can take part of and discuss how it might fit your needs and organization.
