Download or read book Doppler Global Velocimetry Development of a Flight Research Instrumentation System for Application to Non Intrusive Measurements of the Flow Fiel written by National Aeronautics and Space Adm Nasa and published by Independently Published. This book was released on 2018-10-27 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doppler Global Velocimetry (DGV) is a new diagnostic tool that offers potential for flow field measurements in flight by acquiring three-component velocity data in near real-time during flight maneuvers. The feasibility of implementation of a flight DGV system aboard NASA's High-Angle-of-Attack Research Vehicle (HARV) was addressed in this work by identifying the essential characteristics of a flight measurement system and by performing calibration and error tests. Results from this work were: an outline that establishes a preliminary basis for system configurations by analyzing measurement errors, installation issues, and operating requirements; measurement of the accuracy of the DGV technique using a laboratory breadboard DGV system based on a frequency-doubled Nd: YAG laser and iodine Absorption Line Filter (ALF), which showed excellent agreement between the DGV data and pilot measurements on a laminar flow jet with velocities of up to 150 m/sec; a survey of DGV system components and technologies that are relevant to the design of a flight measurement system, including a survey of cameras for the next generation DGV receivers; an assessment of the candidate lasers and absorption line filters for the flight system, resulting in a near-term recommendation of Nd: host lasers and an iodine ALF for both flight and wind tunnel applications. Komine, Hiroshi and Brosnan, Stephen J. and Long, William H. and Stappaerts, Eddy A. Unspecified Center...
Download or read book Doppler Global Velocimetry Development of a Flight Research Instrumentation System for Application to Non intrusive Measurements of the Flow Field written by and published by . This book was released on 1994 with total page 110 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Doppler Global Velocimetry written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 56 pages. Available in PDF, EPUB and Kindle. Book excerpt: Doppler Global Velocimetry (DGV) is a new diagnostic tool that offers potential for flow field measurements in flight by acquiring three-component velocity data in near real-time during flight maneuvers. The feasibility of implementation of a flight DGV system aboard NASA's High-Angle-of-Attack Research Vehicle (HARV) was addressed in this work by identifying the essential characteristics of a flight measurement system and by performing calibration and error tests. Results from this work were: an outline that establishes a preliminary basis for system configurations by analyzing measurement errors, installation issues, and operating requirements; measurement of the accuracy of the DGV technique using a laboratory breadboard DGV system based on a frequency-doubled Nd: YAG laser and iodine Absorption Line Filter (ALF), which showed excellent agreement between the DGV data and pilot measurements on a laminar flow jet with velocities of up to 150 m/sec; a survey of DGV system components and technologies that are relevant to the design of a flight measurement system, including a survey of cameras for the next generation DGV receivers; an assessment of the candidate lasers and absorption line filters for the flight system, resulting in a near-term recommendation of Nd: host lasers and an iodine ALF for both flight and wind tunnel applications. Komine, Hiroshi and Brosnan, Stephen J. and Long, William H. and Stappaerts, Eddy A. Unspecified Center...
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Monthly Catalog of United States Government Publications written by and published by . This book was released on 1994 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Aeronautical Enginnering A Cumulative Index to a Continuing Bibliography supplement 312 written by and published by . This book was released on 1994 with total page 392 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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Download or read book Monthly Catalogue United States Public Documents written by and published by . This book was released on 1994-12 with total page 950 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Laser Techniques Applied to Fluid Mechanics written by R.J. Adrian and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 624 pages. Available in PDF, EPUB and Kindle. Book excerpt: In the tradition of its predecessors, this volume comprises a selection of the best papers presented at the Ninth International Symposium on Applications of Laser Techniques to Fluid Mechanics, held in Lisbon in July 2000. The papers reflect the state-of-the-art in laser applications of laser techniques in fluid mechanics describing novel ideas for instrumentation, instrumentation developments, results of measurements of wall-bounded flows, free flows and flames and flow and combustion in engines. The papers demonstrate the continuing interest in the development of an understanding of new methodologies and implementation in terms of new instrumentation.
Download or read book 30th Aerospace Sciences Meeting and Exhibit 92 0001 92 0030 written by and published by . This book was released on 1992 with total page 460 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1963 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Langley Scientific and Technical Information Output 1994 Volume 1 written by and published by . This book was released on 1995 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Development of a Doppler Global Velocimeter for Whole Field Velocity Measurement and Its Image Processing Schemes Using Single Camera written by Yong Zheng and published by . This book was released on 2015 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: In this study, the development of a Doppler Global Velocimetry (DGV) system using single high speed camera including both hardware and data reduction software is described. DGV is an emerging technique for whole field velocity measurement based upon the Doppler frequency shift of the light scattered by the seeded particles in the flow field. Determination of the Doppler shift is achieved by applying a frequency-to-intensity image conversion in the form of an Absorption Line Filter (ALF) cell containing iodine vapor inside the cell. The Doppler frequency shift of the light scattered by the moving seed particles is then employed to calculate the velocity of the moving particles. Using light sheet generated by applying a set of optics and the laser source and imaging optics, the DGV measures the global velocity of a two-dimensional section of the seeded jet flow. Based upon the DGV system first developed by C. Gaharan [1] in 1996, this study describes a simplified optical system and corresponding data reduction code developments in Matlab. A new laser light source, single lens imaging optical system and a single high speed camera (Phantom V711, Vision Research Inc.) are the main modifications on the hardware. For the previous DGV system developed by C. Gaharan [1], two separate cameras were required for simultaneously recording ALF and REF images of the flow field, while the simplified imaging optical system in this study is able to record both the ALF and REF images on the same screen, which makes applying a single camera adequate to capture the data images required for data reduction and speed calculation without having to sync the capturing operation between separate cameras. An integrated LabView code and a Matlab data reduction code were developed to perform the functions of spatial calibration, intensity calibration, ALF cell calibration, speed calibration and velocity calculation. The system is tested by measuring the surface speed across a 99.06 mm diameter white disc rotating at varied speed from 6000 rpm to 18000 rpm under selected transmission ratios of the ALF cell, as well as a 12.7mm diameter free-expansion turbulent jet operating at a primary Mach number of 0.15. In the DGV system, telecentric lens is applied between the test plane area and the imaging optical system to eliminate the image distortions on the edge area of the lens. In this study, 0.16X Techspec Silver Series Telecentric Lens and 0.06X Gold Series Telecentric Lens are respectively applied, the 0.06X telecentric allows over 6.25 times the light of 0.16X telecentric lens to be collected and recorded by the high speed Phantom camera, corresponding difference resulting from this two telecentric lens is quantified. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/155058
Download or read book Government Reports Announcements Index written by and published by . This book was released on 1996 with total page 634 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Doppler Global Velocimetry written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-17 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: A new measurement technique is being developed by NASA to measure off-surface flow fields. This method, Doppler global velocimetry, will allow quantification of complex three-dimensional flow fields at video camera rates. The entire flow field structure within a selected plane is measured simultaneously rather than by scanned, point-by-point measurements using conventional laser velocimetry. To assess the capability of this new technique, velocity measurements of the vortical flow field above a thin 75-degree delta wing were made in the NASA Langley Basic Aerodynamics Research Tunnel. The operation of the system is described along with the techniques developed to process the output images. The results are then compared with similar measurements obtained using a three component laser velocimeter. Meyers, James F. Langley Research Center ...
Download or read book Doppler Global Velocimeter Development for the Large Wind Tunnels at Ames Research Center written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-06 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Development of an optical, laser-based flow-field measurement technique for large wind tunnels is described. The technique uses laser sheet illumination and charged coupled device detectors to rapidly measure flow-field velocity distributions over large planar regions of the flow. Sample measurements are presented that illustrate the capability of the technique. An analysis of measurement uncertainty, which focuses on the random component of uncertainty, shows that precision uncertainty is not dependent on the measured velocity magnitude. For a single-image measurement, the analysis predicts a precision uncertainty of +/-5 m/s. When multiple images are averaged, this uncertainty is shown to decrease. For an average of 100 images, for example, the analysis shows that a precision uncertainty of +/-0.5 m/s can be expected. Sample applications show that vectors aligned with an orthogonal coordinate system are difficult to measure directly. An algebraic transformation is presented which converts measured vectors to the desired orthogonal components. Uncertainty propagation is then used to show how the uncertainty propagates from the direct measurements to the orthogonal components. For a typical forward-scatter viewing geometry, the propagation analysis predicts precision uncertainties of +/-4, +/-7, and +/-6 m/s, respectively, for the U, V, and W components at 68% confidence. Reinath, Michael S. Ames Research Center...
Download or read book NASA SP written by and published by . This book was released on 1993 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt:
