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Quiet and efficient fans for spacecraft cabin ventilation


Scope Title:

Quietand Efficient Fans for Spacecraft VentilationSystems


Using NASA’s Spacecraft CabinVentilation Fan as a baseline, improvements to maximize fan efficiencyand operational life while minimizing noise, weight, and size aresought. NASA’s Spacecraft Cabin Ventilation Fan isdescribed in a set of reports publicly available on the NASA TechnicalReport Server and is tobe used as the baseline to show improvements in measuredperformance (same or better efficiency) and noise emissions (atleast a 5 dB improvement from the 66 dB Overall SoundPressure Level, measured at 2-ft distance from inlet of the fan, asdescribed in Ref. [8]), at the same design point, bycomparison. Thisfan was intended for use with air at a pressure of 14.7 psi at 70°F. At design point conditions, the design goal flowrate was 150.3 cfm and the design goal total pressure rise was 3.64inches of water. At the design point, this fan had anefficiency of 75% and produced an overall sound pressure level (OASPL)of 66 dB, measured 2 ft from the inlet. Other design goals forthe fan are summarized in Table 1 of NASA Conference Report20230003262, “A Study of Preliminary Design Method for LowNoise Fans,” The geometry and solid model filesfor this fan, to be used for development of abaseline fan for this solicitation, are provided as supplementary materials forthis NASA Technical Memorandum: “Highlights of AeroacousticTests of a Metal Spacecraft Cabin Ventilation Fan Prototype,”NASA TM 20220012622, 2022, SeeReferences for further information.Although thedesign point of this fan is 14.7 psia, testing at 8.2 psia should alsobe performed to characterize and understand extensibility tovehicles and habitats of the cislunar and Mars transitarchitecture. If successful, infusion has high probability,regardless of NASA exploration architecture, and into commercialspace.

Expected TRL or TRL Range at completion of theProject: 3 to 4

Primary TechnologyTaxonomy:

  • Level 1 06Human Health, Life Support, and HabitationSystems
  • Level 2 06.1 EnvironmentalControl & Life Support Systems (ECLSS) and HabitationSystems

DesiredDeliverables of Phase I and PhaseII:

  • Prototype
  • Analysis

DesiredDeliverables Description:

PhaseI deliverables would consist of a fan design (for the samedesign point as the baseline fan) with relevant aerodynamic andacoustic predictions and mechanical, electrical,and thermal analyses.  

Phase II deliverables would consist of a workingprototype fan and measurements with comparisons topredicted aerodynamic and acoustic performance from Phase 1, andalso comparisons of measurements andpredictions to the published aerodynamic and acousticperformance of NASA’s Spacecraft Cabin VentilationFan (the baseline for this SBIR project); see References.Measurement comparisons tothe baseline(with air at apressure of 14.7 psi and temperature of 70°F) should show improvements inmeasured performance (same or better efficiency) and noiseemissions (at least 5 dB improvement from the 66 dBOverall Sound Pressure Level, measured at 2-ft distance from inlet ofthe fan, described in the Sutliff paper, Ref. [8]), at the samedesign point. This fan isintended for use with air at a pressure of 14.7 psi; however,aerodynamic and acoustic testing at 8.2 psia is alsoto be performed and reported to characterize and understandextensibility to vehicles and habitats of the cis-lunar andMars transit architecture.

State of the Art and CriticalGaps:

Current cabin ventilation fans, withduct-borne sound power levels of 80 dB, are too loud andrequire a significant amount of noise controls to meet crew-cabinacoustic requirements.  

Development of prime mover ventilation fans that produceduct-borne sound power levels <70 dB without acoustic treatment,is desired in order to meet crew-cabin acoustic requirements.

For this SBIR project, the figure of merit willbe that the measurement comparisonsto baselineshould show improvements in measured performance (same orbetter efficiency) and noise emissions (at least5 dB improvement from the 66 dB Overall Sound PressureLevel, measured at 2-ft distance from inlet of the fan, as described inRef. [8]), at the same design point.


Relevance / ScienceTraceability:

All NASA and commercial spaceflight vehicle programs would benefit from thistechnology. These include ISS, Orion, Gateway, Human LandingSystem (HLS), and Commercial LEO Destination Program (CLDP),including Commercial Destination Free-flyer (CDFF) and CommercialDestination ISS (CDISS) programs.  This technology can also beused for lunar and Mars surface habitats, as well as the Mars TransferVehicle, and Lunar/Mars Pressurized Rovers.  Successfuloperations from 14.7 psia to 8.2 psia, in explorationatmospheres, would provide extensibility to vehicles andhabitats of the cislunar and Mars transitarchitecture. If successful, infusion has high probability,regardless of NASA exploration architecture and into commercialspace.

[1] Stephens, D., Goodman, J., Buehrle, R.,Mirhashemi, A., Koch, L., Shook, T., Sutliff, D., Allen, C., Matty, C.,“Highlights of Aeroacoustic Tests of a MetalSpacecraft Cabin Ventilation Fan Prototype,” NASA-TM-2022-0012622, 2022,

[2] Tweedt, D. L.,“Aerodynamic Design and Computational Analysis of aSpaceflight Vehicle Cabin Ventilation Fan,”NASA   CR-2010-216329, 2010,

[3] Allen, C., “QuietSpacecraft Cabin Ventilation Fan Development: Motivation andContext,” 2023,

[4] Koch,L. D., “A Study of Preliminary Design Methods for Low NoiseFans,” 2023,

[5] Mirhashemi, A., “QuietSpacecraft Cabin Ventilation Fan: Wake Measurements Results,”2023,

[6] Stephens, D., Goodman, J., Shook,T.,Koch, L., “Quiet Spacecraft Cabin Ventilation Fan:Vibration Measurements Results,” 2023,

[7] Stephens, D., Koch, L. D.,“Quiet Spacecraft Cabin Ventilation Fan: AerodynamicMeasurements Results,” 2023,

[8] Sutliff, D., “QuietSpacecraft Cabin Ventilation Fan: Acoustic MeasurementsResults,” 2023,

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