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Showing 1 to 9 of 9 for “"DGV"”.
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Development and Testing of the Virginia Tech Doppler Global Velocimeter (DGV)
… The Virginia Tech Doppler Global Velocimeter (DGV) system was designed for use in the Virginia Tech Stability Wind Tunnel as a tool for investigating complex three-dimensional separated flow regions. The systems was designed for robustness, ease of use, and for acquisition of low uncertainty …
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Refinement and Verification of the Virginia Tech Doppler Global Velocimeter (DGV)
… referred to as Doppler Global Velocimetry (DGV). Several hardware components in the system were modified and new hardware was added. Significant improvements were made to the procedures used in acquiring DGV data as well as the procedures used in reducing the acquired DGV data. Though …
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Doppler global velocimetry measurements in a wing flow field with tip blowing
A two-component Doppler global velocimetry (DGV) system has been developed, improved, and tested. DGV is a non-intrusive optical velocity measurement technique. DGV measures the Doppler shift of the frequency of the light scattered by seed particles at a specific location. The velocity of the …
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Measurements of Scalar Convection Velocity in Heated and Unheated High-Speed Jets
… Time-resolved Doppler global velocimetry (TR-DGV) from regions of the jet known to produce high levels of acoustic radiation. Past experiments in studying convection velocity are reviewed based on the technique for obtaining the velocities. To add to these experiments, the current work …
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Molecular biological studies of Southern African isolates of maize streak virus
… at the genomic leve 1. A fourth geminivirus (DGV) which infects the grass Digitaria sanguinalis, was compared to known isolates of MSV in order to confirm its identification as an MSV strain: DGV was only distantly serologically related to Southern African MSVs, and is probably a distinct …
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Investigation of Noise Sources in Three-Stream Jets using Turbulence Characteristics
… A Time-Resolved Doppler Global Velocimetry (TR-DGV) Instrument was applied to the Nozzle Acoustic Test Rig (NATR) at NASA's Aero-Acoustic Propulsion Lab (AAPL) to measure convection velocity. Particle image velocimetry (PIV) measurements provided mean velocity and turbulence intensity. Eddy …
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Advanced Instrumentation and Measurements Techniques for Near Surface Flows
… A new variant of Doppler global velocimetry (DGV) known as cross-correlation DGV is developed to measure boundary layer profiles on a wind turbine blade airfoil in the large scale Virginia Tech Stability Wind Tunnel. The instrument provides mean velocity vectors with reduced sensitivity to …
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Turbulence Statistics and Eddy Convection in Heated Supersonic Jets
… the time-resolved Doppler global velocimetry (TR-DGV) measurement technique, statistics of three-component velocity measurements, full Reynolds stress tensors and spectra along the stream-wise direction in a cold, supersonic jet at exit Mach number Mj = 1.4 (design Mach number Md = 1.65) are …
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The Effect of Thermal Non-Uniformity on Coherent Structures in Supersonic Free Jets
… Time-Resolved Doppler Global Velocimetry (TR-DGV) with a sampling frequency of 50 kHz is used to collect flow velocity data that is resolved in both time and space. The experiments for data collection were performed on a heated supersonic jet at the Virginia Tech Advanced Propulsion and Power …