Download or read book On the Generation of Wall Pressure Fluctuations for Turbulent Boundary Layers Over Rough Walls written by Thomas E. Burton and published by . This book was released on 1971 with total page 63 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Turbulent Boundary Layer Wall Pressure Fluctuations on Smooth and Rough Walls written by William K. Blake and published by . This book was released on 1969 with total page 105 pages. Available in PDF, EPUB and Kindle. Book excerpt: Turbulent boundary layer wall pressure measurements were made with 'pinhole' microphones three times smaller (relative to boundary layer thickness) than microphones used in earlier work. The improved high frequency resolution permitted examination of the influence of high frequency eddies on smooth wall pressure statistics. It was found that the space-time decay rate is considerably higher than previously reported. Measurements of cross-spectral density made with 5 Hz band width filters disclosed low phase speeds at low frequency and small separation. Measurements were repeated on rough walls and parallels were drawn from knowledge of a smooth wall boundary layer structure to propose a structure for a rough wall boundary layer. The effect of independently varying roughness height and separation on the large and small scale turbulence structure was deduced from the measurements. It was found that roughness separation affected the very large scale structure, whereas the roughness height influenced the medium and very small scale turbulence. (Author).
Download or read book Wall Pressure Fluctuations at Smooth and Rough Surfaces Under Turbulent Boundary Layers with Favorable and Adverse Pressure Gradients written by Thomas E. Burton and published by . This book was released on 1973 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluctuating wall pressures under turbulent boundary layers with favorable gradients were measured at both smooth and rough walls. Wall pressure intensity was found to vary in proportion to mean wall shear stress between no- gradient and favorable-gradient flows. Adverse gradient boundary layers were studied over smooth and rough walls. These flows were not self-preserving, and results are presented as functions of longitudinal position. Pressure intensities were concentrated into a comparatively narrow band of frequencies. Pressure statistics are discussed.
Download or read book Wall pressure Fluctuations and Pressure velocity Correlations in a Turbulent Boundary Layer written by John S. Serafini and published by . This book was released on 1963 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Turbulent Boundary Layer Wall Pressure Statistics on Smooth and Rough Walls written by William K. Blake and published by . This book was released on 1969 with total page 210 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Bursts and Pressure Fluctuations in Turbulent Boundary Layers written by Peter Bradshaw and published by . This book was released on 1986 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: Surface pressure fluctuations below turbulent boundary layers were studied, in part, because they can be regarded as 'footprints' of passing turbulent eddies. The pressure fluctuations are formally described by a Poisson equation, implying that the pressure fluctuation at a given point is mathematically represented by the integral of a 'source' term over the whole flow field, with a weighting inversely proportional to the distance of the source from the given point. In turbulent boundary layers, fluctuations were made in a low-speed constant pressure the high-frequency part of the wall pressure fluctuations is generated mainly within the inner layer - say, the first 20% of the boundary layer thickness - and the low-frequency part is generated mainly in the outer layer. Measurements of velocity and surface-pressure turbulent boundary layer well downstream of an extensive region of wall roughness. The turbulence near the wall was representative of a smooth-wall flow, while that in the outer layer was typical of the upper stream rough-wall flow. Comparison with previous measurements on an entirely smooth wall illustrates the relative contributions of the inner and outer layers to the surface pressure fluctuations. Further work has been done to compare the VITA (Variable ge) conditional-sampling algorithm withuctuations were more advanced algorithms. Keywords: Turbulent boundary layer, Noise measurement, Statistical analysis, Surface roughness, and VITA algorithm.
Download or read book Wall pressure Fluctuations in a Turbulent Boundary Layer written by John S. Serafini and published by . This book was released on 1962 with total page 122 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Fluctuating Properties of Turbulent Boundary Layers for Mach Numbers Up to 9 written by William D. Harvey and published by . This book was released on 1969 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: Fluctuating properties of turbulent boundary layers for Mach numbers up to 9.
Download or read book WALL PRESSURE FLUCTUATIONS BENEATH AN AXIALLY SUMMERTRIC TURBULEN BOUNDARY LAYER ON A CYLINDER written by CHI-SHENG YANG, WILLIAM W. WILLMARTH and published by . This book was released on 1969 with total page 114 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Pressure Fluctuations in Turbulent Boundary Layers written by M. V. Lowson and published by . This book was released on 1965 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wall pressure Fluctuations and Pressure velocity Correlations in Turbulent Boundary Layer with List of References written by and published by . This book was released on 1963 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Sensitivity to Mean Flow Parameters of the Low Wavenumber Content of the Wall Pressure Under a Turbulent Boundary Layer written by J. E Cole (III.) and published by . This book was released on 1985 with total page 45 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this study is to examine the sensitivity of the low wavenumber portion of the wall pressure field under a turbulent boundary layer to both flow and wall conditions. The analytical procedure makes use of a method for calculating the broadband correlation function of the wall pressure field in which the specific flow characteristics enter through profiles of the mean velocity shear and turbulence intensity across the boundary layer. The basic assumption used to extend the results of this procedure to narrowband frequency characteristics is that there is a range of large spatial separations in which Strouhal scaling is not important. Several specific boundary layers are considered including flows on smooth and rough walls and in zero, favorable, and adverse pressure gradients. Results are presented for the point pressure, the spatial correlation function, and the low wavenumber spectral level. Keywords: GHR(General Hydromechanics Research) program; Wall pressure fluctuations; Low Wavenumber.
Download or read book Predicting Turbulent Boundary Layer Wall Pressure Fluctuations in Adverse Pressure Gradients written by Frank J. Aldrich and published by . This book was released on 2005 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wall Pressure Fluctuations in a Turbulent Boundary Layer written by William W. Willmarth and published by . This book was released on 1956 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Analysis of Turbulent Boundary Layers written by Tuncer Cebeci and published by Elsevier. This book was released on 2012-12-02 with total page 423 pages. Available in PDF, EPUB and Kindle. Book excerpt: Analysis of Turbulent Boundary Layers focuses on turbulent flows meeting the requirements for the boundary-layer or thin-shear-layer approximations. Its approach is devising relatively fundamental, and often subtle, empirical engineering correlations, which are then introduced into various forms of describing equations for final solution. After introducing the topic on turbulence, the book examines the conservation equations for compressible turbulent flows, boundary-layer equations, and general behavior of turbulent boundary layers. The latter chapters describe the CS method for calculating two-dimensional and axisymmetric laminar and turbulent boundary layers. This book will be useful to readers who have advanced knowledge in fluid mechanics, especially to engineers who study the important problems of design.
Download or read book Wall Pressure Fluctuations Associated with Subsonic Turbulent Boundary Layer Flow written by Maxwell Kenneth Bull and published by . This book was released on 1963 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Wall Pressure Fluctuations Induced by Turbulent Boundary Layer Flow with Pressure Gradients written by Nan Hu and published by . This book was released on 2018 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
