| タイトル | Boundary Layer Measurements in a Supersonic Wind Tunnel Using Doppler Global Velocimetry |
| 本文（外部サイト） | http://hdl.handle.net/2060/20100026024 |
| 著者（英） | Cavone, Angelo A.; Lee, Joseph W.; Meyers, James F. |
| 著者所属（英） | NASA Langley Research Center |
| 発行日 | 2010-07-05 |
| 言語 | eng |
| 内容記述 | A modified Doppler Global Velocimeter (DGV) was developed to measure the velocity within the boundary layer above a flat plate in a supersonic flow. Classic laser velocimetry (LV) approaches could not be used since the model surface was composed of a glass-ceramic insulator in support of heat-transfer measurements. Since surface flare limited the use of external LV techniques and windows placed in the model would change the heat transfer characteristics of the flat plate, a novel approach was developed. The input laser beam was divided into nine equal power beams and each transmitted through optical fibers to a small cavity within the model. The beams were then directed through 1.6-mm diameter orifices to form a series of orthogonal beams emitted from the model and aligned with the tunnel centerline to approximate a laser light sheet. Scattered light from 0.1-micron diameter water condensation ice crystals was collected by four 5-mm diameter lenses and transmitted by their respective optical fiber bundles to terminate at the image plane of a standard two-camera DGV receiver. Flow measurements were made over a range from 0.5-mm above the surface to the freestream at Mach 3.51 in steady state and heat pulse injected flows. This technique provides a unique option for measuring boundary layers in supersonic flows where seeding the flow is problematic or where the experimental apparatus does not provide the optical access required by other techniques. |
| NASA分類 | Aerodynamics |
| レポートNO | NF1676L-10718 |
| 権利 | Copyright, Distribution as joint owner in the copyright |
