Anechoic Chamber Testing Infrastructure
Lead test engineer for Whisper Aero's anechoic chamber facility. Instrumented and commissioned a full testing infrastructure from scratch, designed custom test fixtures, and conducted acoustic, thrust, modal, and thermal testing to inform product development.
Skills
Project Overview
As the lead test engineer for Whisper Aero’s anechoic chamber, I took a newly constructed but completely uninstrumented chamber and built it into a production-ready testing facility supporting R&D for ultra-quiet electric propulsor development.
When I arrived, the chamber existed as an empty room with acoustic foam. No mounts, no instrumentation, no DAQ systems, no procedures. Over the course of my internship, I designed, built, and commissioned a modular testing infrastructure capable of acoustic, mechanical, and thermal characterization across multiple test configurations.
The Challenge
Whisper Aero needed a functional test cell to validate the acoustic performance and mechanical characteristics of their consumer electric leaf blower product—but lacked the infrastructure and personnel to operate it.
My role: Serve as the sole test engineer responsible for:
- Instrumentation and data acquisition system integration
- Custom test fixture design and fabrication
- Test procedure development and execution
- Space setup (workstations, equipment, safety systems)
- Data collection, analysis, and reporting to design teams
- Conducting test readiness reviews with engineering stakeholders
PC workbenches and test gear shelving; power supply & DAQ racks; anechoic chamber housed in shipping container
Instrumentation & DAQ Systems
I implemented a comprehensive data acquisition system to support multi-physics testing:
Hardware Integration
Data Acquisition
MBBM VAD PAK MKII DAQ system with custom channel configurations for each test type
Acoustic Instrumentation
5-microphone arrays (377A06 w/ TEDS) for spatial sound pressure level mapping
Mechanical Sensors
Tri-axial accelerometers (356A01), load cells, and tachometers (LT2) for thrust and vibration analysis
Motor Control
In-house PWM motor control system and APD HV Pro motor controller for precise RPM regulation
Electrical & Control Systems
- Power supply rack supporting up to 50V / 20A
- PWM control at ~20 kHz for smooth motor operation
- Sample rates up to ~96 kHz for high-fidelity acoustic capture
- Cable management system for rapid test changeovers
Custom Test Fixtures
I designed and fabricated 5+ unique test fixtures for component and system-level validation:
Free-Free Motor Mount
Engineered a suspension system using precision string mounting to hold BLDC motors in a free-free boundary condition, eliminating structural coupling and enabling pure acoustic and vibrational characterization.
This setup was critical for isolating motor acoustic signatures from mounting structure resonances, enabling accurate motor downselection.
BLDC motor suspended via string in free-free configuration for acoustic testing
Rigid test stand CAD for ANSI-compliant thrust and acoustic measurements
Rigid Blower Test Stand
Precision-engineered test stand designed for structural stability and repeatable test setups, enabling ANSI/OBEI-compliant thrust and acoustic measurements.
Features secure mounting, precise sensor alignment, and operational safety features for high-speed testing cycles.
360° Rotating Blower Stand
Designed an automated rotating test stand enabling full 360° acoustic mapping of the leaf blower propulsor while maintaining secure mounting and precise angular positioning.
This fixture enabled full-directional ANSI acoustic measurements, capturing off-axis sound radiation patterns critical for real-world user experience characterization.
Adjustable 360° rotating stand for full-direction ANSI acoustic measurements
All fixtures were designed in SolidWorks and fabricated using 3D printing, 80/20 aluminum extrusion, and custom CNC-machined metal components.
Testing Campaigns
I conducted comprehensive multi-physics testing across four key areas:
1. Acoustic Characterization
COTS Motor Downselection
Tested 20+ commercial off-the-shelf (COTS) motors to identify the quietest candidates for R&D propulsor integration.
- Measured sound pressure levels across a wide dynamic range with low chamber floor noise
- Analyzed engine order frequencies and tonal content at various operating speeds
- Analyzed propeller passing frequency (PPF) and blade passing frequency (BPF) tonal content
- Delivered ranked acoustic performance data to inform motor procurement
Propulsor & Fan Design Testing
Conducted acoustic validation of fan blade geometries and full propulsor assemblies for the handheld leaf blower product.
Test results directly informed final product design decisions, enabling Whisper to achieve their ultra-quiet performance targets.
2. Thrust Testing (ANSI/OBEI Standards)
Performed standardized thrust measurements using calibrated load cells in accordance with ANSI/OBEI standards for electric leaf blowers:
- Measured thrust across the full operating envelope
- Validated fan efficiency and thrust-to-power ratios
- Ensured rotor balance within specified tolerances
3. Modal Testing
Conducted experimental modal analysis using tri-axial accelerometers to:
- Identify structural resonant modes of propulsor assemblies
- Characterize vibration transmission paths
- Inform structural design changes to avoid resonances in the operating RPM range
4. Thermal Testing
Evaluated thermal performance of propulsor assemblies under sustained operation to ensure safe operating temperatures and validate thermal management strategies.
Facility Ownership & Operations
Beyond testing, I was responsible for the entire test facility:
Infrastructure Setup:
- Purchased and assembled workstations, desks, shelving, and lighting
- Configured PC workstations and monitors for real-time data visualization
- Built power supply racks and organized DAQ equipment
- Implemented safety systems (E-stop, containment features)
- Established cable management and rapid changeover procedures
Test Procedures:
- Developed standardized experimental procedures for repeatability
- Conducted test readiness reviews with Whisper engineers
- Managed test schedules and delivered results to design teams
Impact & Outcomes
Delivered a Production-Ready Test Facility
- ✓Transformed an empty chamber into a fully operational, multi-physics testing facility in ~5 months
- ✓Conducted 20+ motor acoustic tests, directly informing R&D motor selection
- ✓Test data informed critical design decisions for Whisper’s consumer leaf blower product
- ✓Established modular, standards-compliant testing infrastructure enabling rapid iteration
- ✓Delivered repeatable test procedures and data analysis pipelines for continued use
This project showcased my ability to independently scope, design, build, and operate complex test infrastructure—translating engineering requirements into actionable test plans and delivering high-quality data to support product development.