Author:
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 78
Book Description
Wall-pressure Fluctuations and Pressure-velocity Correlations in Turbulent Boundary Layer [with List of References]
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.
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 Turbulent Boundary Layers
Author: John S. Serafini
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 63
Book Description
Pressure fluctuations of a turbulent layer along a plane boundary were investigated. All measurements were made at a nominal free-stream Mach number of 0.6 and an average Reynolds number per foot of 3.45 x 10 to the 6th power in a wind-tunnel facility specially designed for the purpose. The pressure fluctuations were measured with miniature pressure transducers and the velocity fluctuations with hot-wire anemometers. The rootmean-square magnitudes of the wall-pressure fluctuations agree with the Lilley-Hodgson theoretical results, whereas the mean-square spectra do not agree, except over a small range of frequencies. Measurements of the correlations of the wall-pressure fluctuations 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. (Author).
Publisher:
ISBN:
Category : Turbulent boundary layer
Languages : en
Pages : 63
Book Description
Pressure fluctuations of a turbulent layer along a plane boundary were investigated. All measurements were made at a nominal free-stream Mach number of 0.6 and an average Reynolds number per foot of 3.45 x 10 to the 6th power in a wind-tunnel facility specially designed for the purpose. The pressure fluctuations were measured with miniature pressure transducers and the velocity fluctuations with hot-wire anemometers. The rootmean-square magnitudes of the wall-pressure fluctuations agree with the Lilley-Hodgson theoretical results, whereas the mean-square spectra do not agree, except over a small range of frequencies. Measurements of the correlations of the wall-pressure fluctuations 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. (Author).
On the Generation of Wall Pressure Fluctuations for Turbulent Boundary Layers Over Rough Walls
Author: Thomas E. Burton
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 63
Book Description
The study of pressure-velocity correlation in turbulent flow was extended to turbulent boundary layer flow over a roughened wall in the absence of a longitudinal pressure gradient. The results obtained are qualitatively similar to those previously measured over smooth walls. A theory is presented to partially explain the behavior of the measured correlations in both the smooth-wall and rough-wall cases.
Publisher:
ISBN:
Category : Fluid dynamics
Languages : en
Pages : 63
Book Description
The study of pressure-velocity correlation in turbulent flow was extended to turbulent boundary layer flow over a roughened wall in the absence of a longitudinal pressure gradient. The results obtained are qualitatively similar to those previously measured over smooth walls. A theory is presented to partially explain the behavior of the measured correlations in both the smooth-wall and rough-wall cases.
Measurements of the Correlation Between the Fluctuating Velocities and the Fluctuating Wall Pressure in a Thick Turbulent Boundary Layer
Wall-pressure Fluctuations and Pressure-velocity Correlation in Turbulent Boundary Layers
Measurements of the Fluctuating Pressure at the Wall Beneath a Thick Turbulent Boundary Layer
Author: W. W. Willmarth, C. E. Wooldridge
Publisher:
ISBN:
Category :
Languages : en
Pages : 60
Book Description
Publisher:
ISBN:
Category :
Languages : en
Pages : 60
Book Description
Measurements of the Corelation Between the Fluctuating Velocities and the Fluctuating Wall Pressure in a Thick Turbulent Boundary Layer
Surface Pressure Fluctuations Near an Axisymmetric Stagnation Point
Author: Richard D. Marshall
Publisher:
ISBN:
Category : Pressure
Languages : en
Pages : 76
Book Description
Surface pressure fluctuations on a circular disk placed normal to a turbulent air stream were investigated. Turbulence intensities of approximately 10% were produced by a coarse grid installed at the test-section entrance. The turbulent field in the neighborhood of the disk was homogeneous and nearly isotropic. Experimental results indicate that existing linear theories which do not consider distortion of the flow fail to predict the nature of surface pressure fluctuations on a bluff body. Only for wavelengths which are large compared to the body do these theories yield satisfactory results. A strong attenuation of the high frequency components occurs as the flow stagnates. This is accompanied by a transfer of energy from short to long wavelengths. The opposite effect is observed as the flow attains a radial direction and approaches the edge of the disk. A neutral wavelength which undergoes little change in energy was observed. Integral scales of surface pressure fluctuations are much larger than the lateral integral scale of the free-stream turbulence. (Author).
Publisher:
ISBN:
Category : Pressure
Languages : en
Pages : 76
Book Description
Surface pressure fluctuations on a circular disk placed normal to a turbulent air stream were investigated. Turbulence intensities of approximately 10% were produced by a coarse grid installed at the test-section entrance. The turbulent field in the neighborhood of the disk was homogeneous and nearly isotropic. Experimental results indicate that existing linear theories which do not consider distortion of the flow fail to predict the nature of surface pressure fluctuations on a bluff body. Only for wavelengths which are large compared to the body do these theories yield satisfactory results. A strong attenuation of the high frequency components occurs as the flow stagnates. This is accompanied by a transfer of energy from short to long wavelengths. The opposite effect is observed as the flow attains a radial direction and approaches the edge of the disk. A neutral wavelength which undergoes little change in energy was observed. Integral scales of surface pressure fluctuations are much larger than the lateral integral scale of the free-stream turbulence. (Author).