Download or read book Turbulent Wall Pressure Fluctuations in Terms of Spectral Densities Calculated from Discrete and Continuous Orr Sommerfeld Eigenfunctions written by R. Ted Anderson and published by . This book was released on 1986 with total page 316 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Structure of Turbulence and Drag Reduction written by Albert Gyr and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 617 pages. Available in PDF, EPUB and Kindle. Book excerpt: In 1976 a similar titled IUTAM Symposium (Structure of Turbulence and Drag Reduction) was held in Washington . However, the progress made during the last thirteen years as weil as the much promising current research desired a second one this year. In Washington drag reduction by additives and by direct manipulation of the walls (compliant walls and heated surfaces) were discussed. In the meantime it became evident that drag reduction also occurs when turbulence is influenced by geometrical means, e.g. by influencing the pressure distribution by the shape of the body (airfoils) or by the introduction of streamwise perturbances on a body (riblets). In the recent years turbulence research has seen increasing attention being focused on the investigation of coherent structures, mainly in Newtonian fluids. We all know that these structures are a significant feature of turbulent flows, playing an important role in the energy balance in such flows. However their place in turbulence theories as weil as the factors influencing their development are still poorly understood. Consequently, the investigation of phenomena in which the properties of coherent structures are alte red provides a promising means of improving our understanding of turbulent flows in general.
Download or read book 1988 International Symposium on Flow Induced Vibration and Noise Acoustic phenomena and interaction in shear flows over compliant and vibrating surfaces written by M. P. Paidoussis and published by . This book was released on 1988 with total page 176 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book INIS Atomindex written by and published by . This book was released on 1987 with total page 480 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Dissertation Abstracts International written by and published by . This book was released on 1987 with total page 644 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Index to American Doctoral Dissertations written by and published by . This book was released on 1986 with total page 606 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Wall Pressure Fluctuations New Model for Off Axis Cross Spectral Density written by and published by . This book was released on 1996 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Comprehensive Dissertation Index written by and published by . This book was released on 1989 with total page 1016 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Theoretical Estimate of Turbulent Wall Pressure Fluctuations on a Compliant Boundary written by Frank M. White and published by . This book was released on 1966 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: A theoretical estimate is attempted for the effect of a compliant coating on turbulent boundary layer wall pressure fluctuations. The basic derivation shows that the problem reduces to one of finding the distribution in the wall plane of two correlations involving the wall pressure and its normal derivative. Exact expressions are derived for two-dimensional traveling wave pressure/velocity admittance of an isotropic elastic coating. These admittances are combined with some reasonable assumptions about the form of the pressure cross spectral density to yield approximate expressions for the two desired pressure/derivative correlations. Finally, two surface integrals of these correlations result in the wall pressure function in the presence of the compliant boundary. The calculations indicate that the compliant wall increases the mean square wall pressure at low speeds and decreases the pressure fluctuations at high speeds. Unfortunately, the reduction at high speeds probably cannot be achieved in practice because of the related mechanical problem of static divergence of the coating. (Author).
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 Temporal and Spectral Features of Wall Pressure Fluctuations Beneath a Turbulent Boundary Layer written by Carolyn Ceder Karangelen and published by . This book was released on 1991 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Effects of Pressure Gradients on Turbulent Boundary layer Wall pressure Fluctuations written by Howard Hubert Schloemer and published by . This book was released on 1966 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The low-turbulence subsonic wind tunnel was significantly modified so that turbulent boundary-layer pressure fluctuation measurements could be made with adequate signal-to-noise ratio over a wide frequency range. Measurements were made in a mild adverse and a mild favorable pressure gradient with natural transition occurring in the boundary layer. To make certain that the facility was operating correctly and to establish a basis for comparison, the zero-pressure gradient case was investigated. For this case, the spectral density, magnitude of the normalized longitudinal and lateral cross-spectral density functions, and convection velocity as a function of longitudinal separation and frequency were in excellent agreement with other experimenters. When comparison is made to the zero-pressure gradient in the same non-dimensionalized frequency band and at similar non-dimensionalized longitudinal spacings, the convection velocity ratio is higher in the favorable and lower in the adverse pressure gradients, primarily due to the change in shape of the mean velocity profile. The effect of an adverse pressure gradient on the non-dimensionalized spectral density is to increase the low-frequency content without influencing the high-frequency portion appreciably, when compared to the zero-pressure gradient case. (Author).
Download or read book Calculation of Turbulent Boundary Layer Wall Pressure Spectra written by and published by . This book was released on 1993 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study is an investigation into the suitability of various wavevector-frequency models of turbulent boundary layer wall pressure fluctuations for the prediction of experimental measurements of turbulent boundary layer wall pressure spectra. Three separate models of the wavevector- frequency spectrum proposed by D.M. Chase in 1980 and 1987 are evaluated. The wavevector-frequency spectral models are integrated numerically using a formulation for the point wall pressure spectrum (based on the work of Uberoi and Kovasznay). The representation of the wall pressure spectrum used accounts for the effect of a finite sized transducer on the measured wall pressure spectrum. By accounting for the area averaging effect of finite sized transducers on the measured turbulent boundary layer wall pressure spectra, it was possible to use Chase's rigorous formulations for the wavevector-frequency spectrum instead of the point pressure spectrum representations which assume an infinitely small measurement sensor. Results from the numerical integrations are compared to recent experimental data to determine which model of the wavevector- frequency spectrum most accurately predicts measured turbulent boundary layer wall pressure spectra. Data from experiments using fluids with a wide range of physical properties (air, water, and glycerine) are used for comparison purposes. Using the selected model, new empirical constants are established for use in the model for each fluid under consideration. Justification for use of the new empirical constants is given, and current limitations of the wavevector- frequency models are discussed.
Download or read book Simulation of Turbulent Wall Pressure written by Robert L. Ash and published by . This book was released on 1978 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Turbulent Boundary Layer Wall Pressure Fluctuations on an Axisymmetric Body written by H. V. L. Patrick and published by . This book was released on 1977 with total page 37 pages. Available in PDF, EPUB and Kindle. Book excerpt: A buoyancy propelled, fin-stabilized vehicle with a favorable pressure gradient over a major portion of its length was tested at Lake Pend Oreille, Idaho. Turbulent boundary layer wall-pressure fluctuations were measured at numerous locations of the body. In the region of favorable pressure gradient, the normalized wall-pressure spectral density was found to be similar to that on a flat plate. Transition from laminar to turbulent boundary layer flow occurred on the 30-inch-maximum diameter vehicle at transition-length Reynolds numbers as large as 9.2 million. (Author).
Download or read book Statistical Approach to Wall Turbulence written by Sedat Tardu and published by John Wiley & Sons. This book was released on 2013-02-07 with total page 234 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wall turbulence is encountered in many technological applications as well as in the atmosphere, and a detailed understanding leading to its management would have considerable beneficial consequences in many areas. A lot of inspired work by experimenters, theoreticians, engineers and mathematicians has been accomplished over recent decades on this important topic and Statistical Approach to Wall Turbulence provides an updated and integrated view on the progress made in this area. Wall turbulence is a complex phenomenon that has several industrial applications, such as in aerodynamics, turbomachinery, geophysical flows, internal engines, etc. Several books exist on fluid turbulence, but Statistical Approach to Wall Turbulence is original in the sense that it focuses solely on the turbulent flows bounded by solid boundaries. The book covers the different physical aspects of wall turbulence, beginning with classical phenomenological aspects before advancing to recent research in the effects of the Reynolds numbers, near wall coherent structures, and wall turbulent transport process. This book would be of interest to postgraduate and undergraduate students in mechanical, chemical, and aerospace engineering, as well as researchers in aerodynamics, combustion, and all applications of wall turbulence.
