Author: M. K. Bull
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 34
Book Description
The results of measurements of various statistical properties of the fluctuating wall-pressure field associated with turbulent subsonic boundary layer flow in conditions covering a range of values of boundary layer thickness and flow speed are given. The measured quantities include overall rms pressures, frequency spectra, and longitudinal and lateral space-time correlations in both broad and narrow frequency bands. Some experimental values of space-time correlation between wall-pressure fluctuations and turbulent velocity fluctautions at various positions in the boundary layer are also presented. These experimental results and some of their implications on the structure of the wallpressure field and the nature of its convection and decay are discussed. (Author).
Properties of the Fluctuating Wall Pressure Field of a Turbulent Boundary Layer
Author: M. K. Bull
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 34
Book Description
The results of measurements of various statistical properties of the fluctuating wall-pressure field associated with turbulent subsonic boundary layer flow in conditions covering a range of values of boundary layer thickness and flow speed are given. The measured quantities include overall rms pressures, frequency spectra, and longitudinal and lateral space-time correlations in both broad and narrow frequency bands. Some experimental values of space-time correlation between wall-pressure fluctuations and turbulent velocity fluctautions at various positions in the boundary layer are also presented. These experimental results and some of their implications on the structure of the wallpressure field and the nature of its convection and decay are discussed. (Author).
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 34
Book Description
The results of measurements of various statistical properties of the fluctuating wall-pressure field associated with turbulent subsonic boundary layer flow in conditions covering a range of values of boundary layer thickness and flow speed are given. The measured quantities include overall rms pressures, frequency spectra, and longitudinal and lateral space-time correlations in both broad and narrow frequency bands. Some experimental values of space-time correlation between wall-pressure fluctuations and turbulent velocity fluctautions at various positions in the boundary layer are also presented. These experimental results and some of their implications on the structure of the wallpressure field and the nature of its convection and decay are discussed. (Author).
Pressure Fluctuations in Turbulent Boundary Layers
Author: M. V. Lowson
Publisher:
ISBN:
Category : Atmospheric pressure
Languages : en
Pages : 36
Book Description
Publisher:
ISBN:
Category : Atmospheric pressure
Languages : en
Pages : 36
Book Description
Wall-pressure Fluctuations and Pressure-velocity Correlations in a Turbulent Boundary Layer
Author: John S. Serafini
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 88
Book Description
This experimental study was carried out at a free-stream Mach number of 0.6 and a Reynolds number per foot of 3.45 x 106. The magnitudes of the wall-pressure fluctuations agree with the Lilley-Hodgson theoretical results. Space-time correlations of the wall-pressure fluctuations generally agree with Willmarth's results for longitudinal separation distances. The convection velocity of the fluctuations is found to increase with increasing separation distances, and its significance is explained. Measurements with the longitudinal component of the velocity fluctuations indicate that the contributions to the wall-pressure fluctuations are from two regions, an inner region near the wall and an outer region linked with the intermittency.
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 88
Book Description
This experimental study was carried out at a free-stream Mach number of 0.6 and a Reynolds number per foot of 3.45 x 106. The magnitudes of the wall-pressure fluctuations agree with the Lilley-Hodgson theoretical results. Space-time correlations of the wall-pressure fluctuations generally agree with Willmarth's results for longitudinal separation distances. The convection velocity of the fluctuations is found to increase with increasing separation distances, and its significance is explained. Measurements with the longitudinal component of the velocity fluctuations indicate that the contributions to the wall-pressure fluctuations are from two regions, an inner region near the wall and an outer region linked with the intermittency.
Simulation of Turbulent Boundary Layer Wall Pressure Fluctuations
Author: Robert L. Ash
Publisher:
ISBN:
Category : Monte Carlo method
Languages : en
Pages : 54
Book Description
A Monte Carlo simulation of an unsteady, two-dimensional wall pressure field has been developed. The simulation has been evaluated in terms of the statistical properties measured in a variety of turbulent boundary layer experiments and the results are generally in good agreement. Since identifical pressure histories can be created using simulations, it has been possible to investigate the influence of receiver area (or 'microphone' size) on the statistical measurements of identical pressure histories. Based on these simulations, it was possible to conclude that the root mean square pressure levels increase in a quasi linear manner as the receiver size decreases. The trend is in substantial agreement with the experiments of Bull and Thomas, but the threshold of the diameter effect and the magnitude of the r.m.s. increase may be controlled by flow phenomena that are either ignored or improperly simulated. The power spectra are insensitive to receiver size in the energy containing frequency interval. Two-point correlations first show higher correlations with decreasing receiver size, then show poorer correlations as the receiver size becomes small enough to sense fine scale phenomena. The authors believe this simulation computer program can be valuable in studying the response of complex or non-linear structures to quasi-random wall pressure fields. The ability to adjust resolution and simulated flow conditions arbitrarily make it a flexible tool in the analyzing and designing fluid-structural systems.
Publisher:
ISBN:
Category : Monte Carlo method
Languages : en
Pages : 54
Book Description
A Monte Carlo simulation of an unsteady, two-dimensional wall pressure field has been developed. The simulation has been evaluated in terms of the statistical properties measured in a variety of turbulent boundary layer experiments and the results are generally in good agreement. Since identifical pressure histories can be created using simulations, it has been possible to investigate the influence of receiver area (or 'microphone' size) on the statistical measurements of identical pressure histories. Based on these simulations, it was possible to conclude that the root mean square pressure levels increase in a quasi linear manner as the receiver size decreases. The trend is in substantial agreement with the experiments of Bull and Thomas, but the threshold of the diameter effect and the magnitude of the r.m.s. increase may be controlled by flow phenomena that are either ignored or improperly simulated. The power spectra are insensitive to receiver size in the energy containing frequency interval. Two-point correlations first show higher correlations with decreasing receiver size, then show poorer correlations as the receiver size becomes small enough to sense fine scale phenomena. The authors believe this simulation computer program can be valuable in studying the response of complex or non-linear structures to quasi-random wall pressure fields. The ability to adjust resolution and simulated flow conditions arbitrarily make it a flexible tool in the analyzing and designing fluid-structural systems.
The Structure of Turbulent Shear Flow
Author: A. A. R. Townsend
Publisher: Cambridge University Press
ISBN: 9780521298193
Category : Mathematics
Languages : en
Pages : 450
Book Description
Develops a physical theory from the mass of experimental results, with revisions to reflect advances of recent years.
Publisher: Cambridge University Press
ISBN: 9780521298193
Category : Mathematics
Languages : en
Pages : 450
Book Description
Develops a physical theory from the mass of experimental results, with revisions to reflect advances of recent years.
Some Measurements of Longitudinal Space-time Correlations of Wall Pressure Fluctuations in Turbulent Pipe Flow
Author: William Anton Von Winkle
Publisher:
ISBN:
Category : Fluid flow
Languages : en
Pages : 242
Book Description
Measurements made on some of the characteristics of the turbulent pressure field at the wall of a cylindrical pipe yielded root-mean-square pressure levels, power spectra, longitudinal space-time correlations, and convection velocity over a limited range of Reynolds number. The root-mean-square pressure levels were proportional to the dynamic pressure and when nondimensionalized by use of the dynamic pressure were observed to be independent of the Reynolds number and approximately equal to 0.008 over the Reynolds number range examined. The measurements indicate the existence of an apparent downstrea c nvection of the pressure field at a rate which is approximately the mean discharge velocity of the pipe flow. The pressure field in addition to being convected was also dispersed. Estimates of the scale of the turbulence were obtained. A limited statistical analysis of the pressure time history indicates that the amplitude variation is Gaussian. (Author).
Publisher:
ISBN:
Category : Fluid flow
Languages : en
Pages : 242
Book Description
Measurements made on some of the characteristics of the turbulent pressure field at the wall of a cylindrical pipe yielded root-mean-square pressure levels, power spectra, longitudinal space-time correlations, and convection velocity over a limited range of Reynolds number. The root-mean-square pressure levels were proportional to the dynamic pressure and when nondimensionalized by use of the dynamic pressure were observed to be independent of the Reynolds number and approximately equal to 0.008 over the Reynolds number range examined. The measurements indicate the existence of an apparent downstrea c nvection of the pressure field at a rate which is approximately the mean discharge velocity of the pipe flow. The pressure field in addition to being convected was also dispersed. Estimates of the scale of the turbulence were obtained. A limited statistical analysis of the pressure time history indicates that the amplitude variation is Gaussian. (Author).
Temporal and Spectral Features of Wall Pressure Fluctuations Beneath a Turbulent Boundary Layer
Author: Carolyn Ceder Karangelen
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 420
Book Description
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 420
Book Description
Fluctuation Measurements in Supersonic Turbulent Boundary Layers
Author: Alan. L. Kistler
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 62
Book Description
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 62
Book Description
Boundary-Layer Theory
Author: Hermann Schlichting (Deceased)
Publisher: Springer
ISBN: 366252919X
Category : Technology & Engineering
Languages : en
Pages : 814
Book Description
This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics). The new edition features an updated reference list and over 100 additional changes throughout the book, reflecting the latest advances on the subject.
Publisher: Springer
ISBN: 366252919X
Category : Technology & Engineering
Languages : en
Pages : 814
Book Description
This new edition of the near-legendary textbook by Schlichting and revised by Gersten presents a comprehensive overview of boundary-layer theory and its application to all areas of fluid mechanics, with particular emphasis on the flow past bodies (e.g. aircraft aerodynamics). The new edition features an updated reference list and over 100 additional changes throughout the book, reflecting the latest advances on the subject.
Fluctuating Properties of Turbulent Boundary Layers for Mach Numbers Up to 9
Author: William D. Harvey
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 60
Book Description
Fluctuating properties of turbulent boundary layers for Mach numbers up to 9.
Publisher:
ISBN:
Category : Aerodynamics, Hypersonic
Languages : en
Pages : 60
Book Description
Fluctuating properties of turbulent boundary layers for Mach numbers up to 9.