NASA LogoNTRSNTRS - NASA Technical Reports ServerSearchmore_vertCollectionsAboutNewsHelpLogin Back to ResultsGeneration of Performance Model for the Aeolian Wind Tunnel (AWT) Rotor at Reduced PressureThe NASA Jet Propulsion Laboratory (JPL) designed the Mars Helicopter (MH) in collaboration with AeroVironment Inc., NASA Ames Research Center, and NASA Langley Research Center to explore the possibility of a vertical takeoff and landing (VTOL) Unmanned Aerial Vehicle (UAV) for flight on Mars. A 40-inch-diameter Aeolian Wind Tunnel (AWT) rotor, roughly approximating the proposed MH design by JPL, was tested in forward flight at Mars atmospheric pressure at the NASA Ames Planetary Aeolian Laboratory (PAL) in support of MH research efforts. This report describes the generation of the rotor model used to correlate with that experimental effort as reported by Ament and Koning. The 40-inch-diameter rotor was 3D-scanned and transformed into an airfoil deck. The scanned rotor airfoil sections are analyzed using C81 Generator (C81Gen) to generate the sectional aerodynamic coefficients for comprehensive analyses. A mid-fidelity computational fluid dynamics (CFD) simulation using Rotorcraft CFD (RotCFD) is pursued to efficiently estimate rotor hover and forward flight performance. Simulations at two pressures, 7 mbar (approximate Martian atmospheric pressure) and 1018 mbar (1 atmosphere), are performed to gain an understanding of the performance differences and Reynolds number effects observed. Experimental 1-atmosphere thrust for single- and dual-rotor isolated hover cases correlate well with the modeled rotor. Performance results at reduced pressure (7 mbar) show a drastic decrease in lift for equivalent RPMs tested at 1 atmosphere. Although this is primarily due to pressure reduction, Reynolds number effects also contribute to this decrease, as airfoil lift and drag coefficients are affected when compared with 1-atmosphere results. Further, simulated rotor power coefficient shows drastic increases at reduced pressures, attributed to laminar boundary layer separation, as described in Koning et al. for the MH rotor analysis. PAL experimental Martian Surface Wind Tunnel (MARSWIT) results are presented in the paper by Ament and Koning. The very low Reynolds number range is currently not well understood and presents various challenges for both experimentation and simulation.Document ID20180008699Acquisition SourceAmes Research CenterDocument TypeContractor Report (CR)AuthorsKoning, Witold J. F.*(Science and Technology Corp. Moffett Field, CA, United States)*Date AcquiredDecember 20, 2018Publication DateDecember 10, 2018Subject CategoryAeronautics (General)Report/Patent NumberARC-E-DAA-TN50404NASA/CR-2018ý219737Funding Number(s)CONTRACT_GRANT: NNA16BD60CDistribution LimitsPublicCopyrightPublic Use Permitted.Available DownloadsNameType20180008699.pdfSTIcloud_downloadcontent_copyvisibilityRelated RecordsThere are no records associated with this record.visibility_offNo Preview Available
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