Fluctuation Measurements in Supersonic Turbulent Boundary Layers
Author: Alan. L. Kistler
Publisher:
Published: 1958
Total Pages: 62
ISBN-13:
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Author: Alan. L. Kistler
Publisher:
Published: 1958
Total Pages: 62
ISBN-13:
DOWNLOAD EBOOKAuthor: Virgil A. Sandborn
Publisher:
Published: 1974
Total Pages: 168
ISBN-13:
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Publisher:
Published: 1969
Total Pages: 0
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DOWNLOAD EBOOKSurface pressure fluctuations associated with transitional and turbulent boundary-layer flows on a sharp, slender cone at supersonic Mach numbers were experimentally investigated in a 40- by 40-in. supersonic wind tunnel using a flush-mounted 0.25-in.-diam microphone. The results at Mach numbers 3 and 4 demonstrate the feasibility of locating microphones onboard wind tunnel test models to measure overall pressure fluctuations and power spectral distributions in transitional and fully developed turbulent flows. Transition Reynolds numbers determined using a surface microphone are compared with two other established methods of detection. Selected boundary-layer pressure fluctuation characteristics (power spectral density and root-mean-square values) and transition profiles are presented. Methods of data acquisition and analysis are discussed.
Author:
Publisher:
Published: 1969
Total Pages: 35
ISBN-13:
DOWNLOAD EBOOKSurface pressure fluctuations associated with transitional and turbulent boundary-layer flows on a sharp, slender cone at supersonic Mach numbers were experimentally investigated in a 40- by 40-in. supersonic wind tunnel using a flush-mounted 0.25-in.-diam microphone. The results at Mach numbers 3 and 4 demonstrate the feasibility of locating microphones onboard wind tunnel test models to measure overall pressure fluctuations and power spectral distributions in transitional and fully developed turbulent flows. Transition Reynolds numbers determined using a surface microphone are compared with two other established methods of detection. Selected boundary-layer pressure fluctuation characteristics (power spectral density and root-mean-square values) and transition profiles are presented. Methods of data acquisition and analysis are discussed.
Author: Alexander J. Smits
Publisher: Springer Science & Business Media
Published: 2006-05-11
Total Pages: 418
ISBN-13: 0387263055
DOWNLOAD EBOOKA good understanding of turbulent compressible flows is essential to the design and operation of high-speed vehicles. Such flows occur, for example, in the external flow over the surfaces of supersonic aircraft, and in the internal flow through the engines. Our ability to predict the aerodynamic lift, drag, propulsion and maneuverability of high-speed vehicles is crucially dependent on our knowledge of turbulent shear layers, and our understanding of their behavior in the presence of shock waves and regions of changing pressure. Turbulent Shear Layers in Supersonic Flow provides a comprehensive introduction to the field, and helps provide a basis for future work in this area. Wherever possible we use the available experimental work, and the results from numerical simulations to illustrate and develop a physical understanding of turbulent compressible flows.
Author: Jonathan H. Watmuff
Publisher:
Published: 1987
Total Pages: 41
ISBN-13:
DOWNLOAD EBOOKMeasurements of structure angle in a supersonic turbulent boundary layer with zero and adverse pressure gradients are presented. Conditionally sampled measurements of u, v, and uv are presented along with quadrant analysis of the turbulent fluctuations. The latter suggests ambiguities associated with the interpretation of VITA measurements. Preliminary results of experiments on artificially generated hairpin vortices are also discussed. Measurements indicate a high degree of similarity between the signatures of these hairpin structures and ensemble averaged events in the turbulent boundary layer. Keywords: Turbulence, Boundary layer, Supersonic Flow.
Author: D.J.M. Williams
Publisher:
Published: 1960
Total Pages:
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DOWNLOAD EBOOKAuthor: W. V. Speaker
Publisher:
Published: 1966
Total Pages: 164
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Publisher:
Published: 1994
Total Pages: 115
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DOWNLOAD EBOOKThe effect of a favorable pressure gradient on the turbulent flow structure in a Mach 2.9 boundary layer (Re/m approx. 1.5 x 10(exp 7)) is investigated experimentally. Conventional flow and hot film measurements of turbulent fluctuation properties have been made upstream of and along an expansion ramp. Upstream measurements were taken in a zero pressure gradient boundary layer 44 cm from the nozzle throat in a 6.35 cm square test section. Measurements are obtained in the boundary layer, above the expansion ramp, 71.5 cm from the nozzle throat. Mean flow and turbulent flow characteristics are measured in all three dimensions. Comparisons are made between data obtained using single and multiple-overheat cross-wire anemometry as well as conventional mean flow probes. Conventional flow measurements were taken using a Pitot probe and a 10 degree cone static probe. Flow visualization was conducted via imaging techniques (Schlieren and shadowgraph photographs). Results suggest that compressibility effects, as seen through the density fluctuations in the Reynolds shear stress are roughly 10% relative to the mean velocity and are large relative to the velocity fluctuations. This is also observed in the total Reynolds shear stress; compressibility accounts for 50 - 75% of the total shear. This is particularly true in the favorable pressure gradient region, where though the peak fluctuation intensities are diminished, the streamwise component of the mean flow is larger, hence the contribution of the compressibility term is significant in the Reynolds shear.
Author: Alexander J. Smits
Publisher:
Published: 1990
Total Pages: 40
ISBN-13:
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