Challenge
Test mid-size payload for launch on a SpaceX Falcon 9 Heavy launch vehicle. Test in ISO8 class clean room. Save customer time vs. prior DFAN tests. Solve previously noted issues with vertical diffusivity presented by vertical line arrays.
Approach
- Design NEUTRON System configuration to support covering all surfaces of test article in diffuse uniform field.
- Provide both horizontal and vertical diffusivity via uncorrelated drives to individual NEUTRON devices. Response monitoring microphones placed in field to qualify non-control positions via customer analysis.
- All-in-one design of NEUTRON enables same test article to utilize 25-50% less devices than concert sound system approach, saving significant setup time.
- System is ISO8-capable, implement ARS cleanliness procedure at warehouse (clean and wrap, clean trailer, wipedown and sticky mats onsite, all ARS supporting infrastructure (amplifiers, racks, etc.) all clean-room-ready by design).
Results
Test performed successfully and to specification, ARS met all acoustic requirements with regard to level, accuracy, and required tolerances. Saved 1.5 days to schedule vs. previous vendors. QA reported zero contamination issues with NEUTRON System during test while following ARS+Customer SOP. Flight hardware responded as expected to diffuse acoustic field and results correlated strongly to customer FEM simulations. ARS delivered all raw, unprocessed time history files from control and monitoring microphones for additional study by customer analysis team.
Specifications
DUT Size: 6ft x 6ft x 8ft
System Size: 24 NEUTRON’s in 6×4 configuration
Spectrum: SpaceX Falcon9 Heavy MPE +3dB (138.6dB OASPL)
Duration: 60 Seconds
Location: Confidential
Post-processed test result data: 1/3Oct Freq. Resp. | PSD Freq. Resp. | Mic-to-Mic Coherence
