1 / 16

Advanced Videogrammetry for Aeroelastic Deformation Measurements at NASA Wind Tunnels

Explore the state-of-the-art videogrammetry technique used for aeroelastic deformation measurements in NASA wind tunnels, including components, dynamics up to 1000 Hz, video processing, calibration, facilities, and future applications. See the latest advancements and challenges faced in aerodynamics research.

earlt
Download Presentation

Advanced Videogrammetry for Aeroelastic Deformation Measurements at NASA Wind Tunnels

An Image/Link below is provided (as is) to download presentation Download Policy: Content on the Website is provided to you AS IS for your information and personal use and may not be sold / licensed / shared on other websites without getting consent from its author. Content is provided to you AS IS for your information and personal use only. Download presentation by click this link. While downloading, if for some reason you are not able to download a presentation, the publisher may have deleted the file from their server. During download, if you can't get a presentation, the file might be deleted by the publisher.

E N D

Presentation Transcript

  1. MODEL DEFORMATION MEASUREMENTS AT NASA WIND TUNNELS USING VIDEOGRAMMETRY

  2. AEROELASTIC DEFORMATION MEASUREMENTS STATE-OF-THE-ART twist due to aero loads main wing element • CURRENT CHALLENGES • Components (high lift) • flap, gap, and overhang • Dynamics: up to 1000 Hz

  3. WHAT IS VIDEOGRAMMETRY • Photogrammetry + video image processing • Extraction of 2D or 3D info from 2D image data • 1 camera  3D rigid body or 2D deformation • (1D must be known for 2D deformation) • 2 or more cameras  3D deformation

  4. 2.5 m VIDEOGRAMMETRIC TECHNIQUE(VMD) NTF test section • Optical targets • Single-camera photogrammetry X, Z computed with Y known • video-rate CCD camera • Frame grabber • Auto target location or tracking • 3-step calibration procedure Looking downstream (+X) Z Y

  5. RETROREFLECTIVE TARGETS

  6. 1 2 3 4 5 6 7 Z Flow X POLISHED PAINT TARGETSNational Transonic Facility Semispan POLISHED PAINT TECHNIQUE • 0.0005 inch (1/2 mil) thickness • Feathered edges (no abrupt steps) • 10 inch surface roughness • Precision templates Full-span

  7. CALIBRATION (1) image plane corrections (2) coordinate system (3) Wind-off polars for angle and X,Z

  8. FACILITIES • National Transonic Facility • Transonic Dynamics Tunnel • 16-Ft Transonic Wind Tunnel • Unitary Plan Wind Tunnel • Ames 12-Ft Pressure Tunnel Deformation measurements made from subsonic to supersonic - high lift, cruise, onset of buffet

  9. NATIONAL TRANSONIC FACILITY(NTF) • Cryogenic • High Re  high Q • Last 9 tests: deformation

  10. -5 1 2 3 4 5 6 7 Z 24 Flow X VECTOR DISPLACEMENTS

  11. CHANGE IN GAP AND OVERHANG DUE TOAERODYNAMIC LOADING

  12. DYNAMIC DEFORMATION OF SEMISPAN MODEL Transonic Dynamics Tunnel Dq, deg Time, sec Inboard f = 10.6 Hz Power Outboard f = 10.6 Hz Power f, Hz

  13. DEFORMATION CONTOURS DZ, inch h = 1 h = 0 D t, sec 0.000 0.017 0.034 0.050 0.067

  14. DZ, inch 0 . 0 8 0 . 0 6 0 . 0 4 0 . 0 2 0 - 0 . 0 2 - 0 . 0 4 - 0 . 0 6 - 0 . 0 8 MICRO AIR VEHICLEDEFORMATION CONTOURS

  15. 867 FRAMES/SEC DATA ACQUIREDBASIC AERODYNAMIC RESEARCH TUNNEL

  16. CONCLUDING REMARKS • Videogrammetry useful for static and dynamic aeroelastic measurements in wind tunnels • Single-camera, single-view technique is workhorse • Useful for a number of tests at NASA facilities • National Transonic Facility (last 9 customer tests) • 16-Ft Transonic Wind Tunnel • Transonic Dynamics Tunnel • Unitary Plan Wind Tunnel • Ames 12-Ft Pressure Tunnel • Future efforts • Dynamic measurements up to 1000 Hz • Micro air vehicles • Ultralight and inflatable large space structures • Robustness with and without targets

More Related