Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781792670725
Category :
Languages : en
Pages : 30
Book Description
A review is given of the nature, present status, and capabilities of two laser spectroscopic methods for the simultaneous measurement of temperature, density, and their fluctuations owing to turbulence in high speed wind tunnel flows. One method is based on the two frequency excitation of nitric oxide seeded into a nitrogen flow, using tunable dye lasers. The second, more recent method relies on the excitation of oxygen in air flows using a tunable, ArF excimer laser. Signal are obtained from both the laser induced fluorescence and from Raman scattering of the same laser pulse. Measurements are demonstrated in the turbulent boundary layer of a Mach-2 channel flow. Mckenzie, Robert L. and Fletcher, Douglas G. Ames Research Center NASA-TM-103928, A-92076, NAS 1.15:103928 RTOP 505-59-40...
Laser-Spectroscopic Measurement Techniques for Hypersonic, Turbulent Wind Tunnel Flows
Author: National Aeronautics and Space Adm Nasa
Publisher: Independently Published
ISBN: 9781792670725
Category :
Languages : en
Pages : 30
Book Description
A review is given of the nature, present status, and capabilities of two laser spectroscopic methods for the simultaneous measurement of temperature, density, and their fluctuations owing to turbulence in high speed wind tunnel flows. One method is based on the two frequency excitation of nitric oxide seeded into a nitrogen flow, using tunable dye lasers. The second, more recent method relies on the excitation of oxygen in air flows using a tunable, ArF excimer laser. Signal are obtained from both the laser induced fluorescence and from Raman scattering of the same laser pulse. Measurements are demonstrated in the turbulent boundary layer of a Mach-2 channel flow. Mckenzie, Robert L. and Fletcher, Douglas G. Ames Research Center NASA-TM-103928, A-92076, NAS 1.15:103928 RTOP 505-59-40...
Publisher: Independently Published
ISBN: 9781792670725
Category :
Languages : en
Pages : 30
Book Description
A review is given of the nature, present status, and capabilities of two laser spectroscopic methods for the simultaneous measurement of temperature, density, and their fluctuations owing to turbulence in high speed wind tunnel flows. One method is based on the two frequency excitation of nitric oxide seeded into a nitrogen flow, using tunable dye lasers. The second, more recent method relies on the excitation of oxygen in air flows using a tunable, ArF excimer laser. Signal are obtained from both the laser induced fluorescence and from Raman scattering of the same laser pulse. Measurements are demonstrated in the turbulent boundary layer of a Mach-2 channel flow. Mckenzie, Robert L. and Fletcher, Douglas G. Ames Research Center NASA-TM-103928, A-92076, NAS 1.15:103928 RTOP 505-59-40...
Laser-spectroscopic Measurement Techniques for Hypersonic, Turbulent Wind Tunnel Flows
Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 18
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 18
Book Description
New Trends in Instrumentation for Hypersonic Research
Author: A. Boutier
Publisher: Springer Science & Business Media
ISBN: 9401118280
Category : Science
Languages : en
Pages : 612
Book Description
Because of the growing interest in hypersonic flows, the AGARD Fluid Dynamics Panel initiated a sub-working group on instrumentation for hypersonics in 1989. This sub-group, chaired by J. WENDT (VKI -Belgium), was composed of: A. BOUTIER (ONERA -France), K. BUTEFISCH (DLR -Germany), R. CATTOLICA (SANDIA Lab. -USA), V. CLINE (AEDC -USA), A. GIRARD (ONERA -France), R. McKENZIE (NASA Ames -USA), S. OCHELTREE (NASA Langley -USA) and G. SMEETS (ISL -Franco-German Inst.). As a result of several meetings, the idea came to organize this workshop, 27th April - 1st May 1992, on "New Trends in Instrumentation for Hypersonic Research", at Le Fauga-Mauzac ONERA center, in France, where the new hot-shot arc-heated facility F4, as well as a new conference building, were recently completed. This workshop has been organized in close connection with the AGARD FDP Symposium to be held in Torino 4 - 8 May 1992 on "Theoretical and Experimental Methods in Hypersonic Flows": the main conclusions and ideas expressed by the papers and during the discussions of this workshop are reported in session 7 and have been presented in Torino in a special Instrumentation session. As chairman of this workshop, I express many thanks to the Organizing Committee composed of Karl BUTEFISCH, Andre GIRARD, Stewart OCHELTREE and John WENDT for their very constructive help, leading to a meeting that was recognized to be very fruitful for all the participants.
Publisher: Springer Science & Business Media
ISBN: 9401118280
Category : Science
Languages : en
Pages : 612
Book Description
Because of the growing interest in hypersonic flows, the AGARD Fluid Dynamics Panel initiated a sub-working group on instrumentation for hypersonics in 1989. This sub-group, chaired by J. WENDT (VKI -Belgium), was composed of: A. BOUTIER (ONERA -France), K. BUTEFISCH (DLR -Germany), R. CATTOLICA (SANDIA Lab. -USA), V. CLINE (AEDC -USA), A. GIRARD (ONERA -France), R. McKENZIE (NASA Ames -USA), S. OCHELTREE (NASA Langley -USA) and G. SMEETS (ISL -Franco-German Inst.). As a result of several meetings, the idea came to organize this workshop, 27th April - 1st May 1992, on "New Trends in Instrumentation for Hypersonic Research", at Le Fauga-Mauzac ONERA center, in France, where the new hot-shot arc-heated facility F4, as well as a new conference building, were recently completed. This workshop has been organized in close connection with the AGARD FDP Symposium to be held in Torino 4 - 8 May 1992 on "Theoretical and Experimental Methods in Hypersonic Flows": the main conclusions and ideas expressed by the papers and during the discussions of this workshop are reported in session 7 and have been presented in Torino in a special Instrumentation session. As chairman of this workshop, I express many thanks to the Organizing Committee composed of Karl BUTEFISCH, Andre GIRARD, Stewart OCHELTREE and John WENDT for their very constructive help, leading to a meeting that was recognized to be very fruitful for all the participants.
Measurement Techniques for Hypersonic Flows
Author:
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 420
Book Description
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 420
Book Description
Scientific and Technical Aerospace Reports
Author:
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704
Book Description
Publisher:
ISBN:
Category : Aeronautics
Languages : en
Pages : 704
Book Description
A Method for Measuring Temperatures and Densities in Hypersonic Wind Tunnel Air Flows Using Laser-induced O2 Fluorescence
Author: Gabriel Laufer
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Turbulence Measurements in High-speed Wind Tunnels Using Focusing Laser Differential Interferometry
Author: Matthew Fulghum
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Characterization of freestream disturbances and their effect on laminar boundary layer transition is of great importance in high-speed wind tunnel testing, where significant differences between the behavior of scale-model and free-flight transition have long been noted. However, the methods traditionally used to perform this characterization in low-speed flows present significant difficulties when applied to supersonic and especially hypersonic wind tunnels. The design and theory of a focusing laser differential interferometer (FLDI) instrument, originally invented by Smeets at the Institut Saint-Louis in the 1970s and used recently by Parziale in the CalTech T5 shock tunnel, is presented. It is a relatively-simple, non-imaging common-path interferometer for measuring refractive signals from transition and turbulence, and it has a unique ability to look through facility windows, ignore sidewall boundary-layers and vibration, and concentrate only on the refractive signal near a pair of sharp beam foci in the core flow. The instrument's low cost and ease of implementation make it a promising alternative to traditional hot-wire anemometry and particle-based methods for turbulence characterization. Benchtop experiments using a turbulent supersonic air jet demonstrate its focusing ability, frequency response, unwanted signal rejection, and ease of use. The instrument is used to optically interrogate the flow in the Penn State University Supersonic Wind Tunnel and USAF AEDC Hypervelocity Tunnel 9 for measurement of the overall intensity and spectra of freestream disturbances. Precise characterization of the strength and spectral content of the disturbances provides insight into their nature and potential effect upon boundary layer transition. A special feature of the FLDI instrument used here is the replacement of traditional fixed Wollaston prisms with variable Sanderson prisms for laser-beam separation and recombination.
Publisher:
ISBN:
Category :
Languages : en
Pages :
Book Description
Characterization of freestream disturbances and their effect on laminar boundary layer transition is of great importance in high-speed wind tunnel testing, where significant differences between the behavior of scale-model and free-flight transition have long been noted. However, the methods traditionally used to perform this characterization in low-speed flows present significant difficulties when applied to supersonic and especially hypersonic wind tunnels. The design and theory of a focusing laser differential interferometer (FLDI) instrument, originally invented by Smeets at the Institut Saint-Louis in the 1970s and used recently by Parziale in the CalTech T5 shock tunnel, is presented. It is a relatively-simple, non-imaging common-path interferometer for measuring refractive signals from transition and turbulence, and it has a unique ability to look through facility windows, ignore sidewall boundary-layers and vibration, and concentrate only on the refractive signal near a pair of sharp beam foci in the core flow. The instrument's low cost and ease of implementation make it a promising alternative to traditional hot-wire anemometry and particle-based methods for turbulence characterization. Benchtop experiments using a turbulent supersonic air jet demonstrate its focusing ability, frequency response, unwanted signal rejection, and ease of use. The instrument is used to optically interrogate the flow in the Penn State University Supersonic Wind Tunnel and USAF AEDC Hypervelocity Tunnel 9 for measurement of the overall intensity and spectra of freestream disturbances. Precise characterization of the strength and spectral content of the disturbances provides insight into their nature and potential effect upon boundary layer transition. A special feature of the FLDI instrument used here is the replacement of traditional fixed Wollaston prisms with variable Sanderson prisms for laser-beam separation and recombination.
Monthly Catalog of United States Government Publications
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 846
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 846
Book Description
Monthly Catalogue, United States Public Documents
Author:
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1388
Book Description
Publisher:
ISBN:
Category : Government publications
Languages : en
Pages : 1388
Book Description
Three Dimensional Diagnostic Techniques
Author: J. C. F. Wang
Publisher:
ISBN:
Category : Air flow
Languages : en
Pages : 58
Book Description
The report describes a study of 3-D diagnostic techniques for measurements of flow velocity in the test section of a hypersonic wind tunnel. A successful on-site demonstration using a laser velocimeter system is discussed in detail. The close agreement between the LV and theoretical results demonstrates the feasibility of employing this technique in supersonic or hypersonic flow situations. Some technical experiences and considerations concerning the LV system as well as a few improvements for further development are also reported. (Modified author abstract).
Publisher:
ISBN:
Category : Air flow
Languages : en
Pages : 58
Book Description
The report describes a study of 3-D diagnostic techniques for measurements of flow velocity in the test section of a hypersonic wind tunnel. A successful on-site demonstration using a laser velocimeter system is discussed in detail. The close agreement between the LV and theoretical results demonstrates the feasibility of employing this technique in supersonic or hypersonic flow situations. Some technical experiences and considerations concerning the LV system as well as a few improvements for further development are also reported. (Modified author abstract).