Fluctuation Measurements in Supersonic Turbulent Boundary Layers

Fluctuation Measurements in Supersonic Turbulent Boundary Layers PDF Author: Alan. L. Kistler
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 62

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Fluctuation Measurements in Supersonic Turbulent Boundary Layers

Fluctuation Measurements in Supersonic Turbulent Boundary Layers PDF Author: Alan. L. Kistler
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 62

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A Review of Turbulence Measurements in Compressible Flow

A Review of Turbulence Measurements in Compressible Flow PDF Author: Virgil A. Sandborn
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 168

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ACOUSTIC MEASUREMENTS IN SUPERSONIC TRANSITIONAL BOUNDARY LAYERS.

ACOUSTIC MEASUREMENTS IN SUPERSONIC TRANSITIONAL BOUNDARY LAYERS. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 35

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Surface 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.

Measurements of the Surface Pressure Fluctuations in a Turbulent Boundary Layer in Air at Supersonic Speeds

Measurements of the Surface Pressure Fluctuations in a Turbulent Boundary Layer in Air at Supersonic Speeds PDF Author: D.J.M. Williams
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Fundamental Aspects of the Structure of Supersonic Turbulent Boundary

Fundamental Aspects of the Structure of Supersonic Turbulent Boundary PDF Author: Jonathan H. Watmuff
Publisher:
ISBN:
Category :
Languages : en
Pages : 41

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Measurements 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.

Turbulent Shear Layers in Supersonic Flow

Turbulent Shear Layers in Supersonic Flow PDF Author: Alexander J. Smits
Publisher: Springer Science & Business Media
ISBN: 0387263055
Category : Science
Languages : en
Pages : 418

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Book Description
A 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.

ACOUSTIC MEASUREMENTS IN SUPERSONIC TRANSITIONAL BOUNDARY LAYERS.

ACOUSTIC MEASUREMENTS IN SUPERSONIC TRANSITIONAL BOUNDARY LAYERS. PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 0

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Book Description
Surface 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.

Measurements in the Turbulent Boundary Layer at Constant Pressure in Subsonic and Supersonic Flow. Part II. Laser-Doppler Velocity Measurements

Measurements in the Turbulent Boundary Layer at Constant Pressure in Subsonic and Supersonic Flow. Part II. Laser-Doppler Velocity Measurements PDF Author: Paul E. Dimotakis
Publisher:
ISBN:
Category :
Languages : en
Pages : 89

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Experiments have been carried out using laser-Doppler velocimetry in conjunction with Pitot and surface-friction instrumentation for the measurement of the mean flow, the velocity fluctuations, and the Reynolds stresses in turbulent boundary layers at constant pressure in subsonic and supersonic flows. Part I of this work was a detailed analysis of the mean flow as observed using Pitot-tube, Preston-tube, and floating-element balance instrumentation. The present work (Part II) is a description of both the mean and the fluctuating components of the flow, and of the Reynolds stress as observed using a dual forward-scattering laser-Doppler velocimenter. A detailed description of the instrument, and of the data analysis techniques, have been included in order to fully document the data. A detailed comparison is made between the laser-Doppler results and those presented in Part I, and an assessment is made of the ability of the laser-Doppler velocimeter to measure the details of the flows involved.

Compressible Turbulence Measurements in a Supersonic Boundary Layer Including Favorable Pressure Gradient Effects

Compressible Turbulence Measurements in a Supersonic Boundary Layer Including Favorable Pressure Gradient Effects PDF Author:
Publisher:
ISBN:
Category :
Languages : en
Pages : 115

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The 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.

Investigation of Supersonic Boundary Layer Transition and Turbulent Structure

Investigation of Supersonic Boundary Layer Transition and Turbulent Structure PDF Author: Alexander J. Smits
Publisher:
ISBN:
Category : Rayleigh scattering
Languages : en
Pages : 40

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