Download or read book Effect of Pressure Gradients on Plate Response and Radiation in a Supersonic Turbulent Boundary Layer written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: Using the model developed by the author for zero-pressure gradient turbulent boundary layers, results are obtained for adverse and favorable pressure gradients. It is shown that when a flexible plate is located in an adverse pressure gradient area, it vibrates more than if it were in a favorable pressure gradient one. Therefore the noise generated by the plate in an adverse pressure gradient is much greater than that due to the plate in a favorable pressure gradient. The effects of Reynolds number and boundary layer thickness are also analyzed and found to have the same effect in both adverse and favorable pressure gradient cases. Increasing the Reynolds number is found to increase the loading on the plate and therefore acoustic radiation. An increase in boundary layer thickness is found to decrease the level of the high frequencies and therefore the response and radiation at these frequencies. The results are in good qualitative agreement with experimental measurements. Frendi, Abdelkader Langley Research Center NAS1-19700; NAS1-96014; RTOP 537-06-37-20...

Download or read book Effect of Pressure Gradients on Plate Response and Radiation in a Supersonic Turbulent Boundary Layer written by and published by . This book was released on 1997 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effects of an Adverse Pressure Gradient on the Behavior of a Flat Plate Supersonic Turbulent Boundary Layer written by E.M. Fernando and published by . This book was released on 1987 with total page 12 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Supersonic Turbulent Boundary Layer in an Adverse Pressure Gradient written by Emerick Manley Fernando and published by . This book was released on 1988 with total page 246 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Anomalous Effects of Pressure Gradient on Supersonic Turbulent Boundary Layers written by P. Bradshaw and published by . This book was released on 1972 with total page 13 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Pressure Gradient Effects on Supersonic Boundary Layer Turbulence written by A. J. Laderman and published by . This book was released on 1979 with total page 182 pages. Available in PDF, EPUB and Kindle. Book excerpt: Measurements of mean flow profiles at several streamwise locations in a supersonic turbulent boundary layer growing under a continuous adverse pressure gradient are reported. Tests were performed at a freestream Mach number of 3, for an adiabatic wall, using two curved ramps designed to produce constant pressure gradient flows. The velocity profile data, when transformed to incompressible coordinates, are in good agreement with Coles universal 'wall-wake' velocity profile and they indicate that the boundary layer is in local equilibrium and essentially independent of upstream history. In addition, the Coles wake parameters and Clauser shape factors, characterizing the transformed profiles, are in accord with the results of low speed correlations of adverse pressure gradient flows. The turbulent transport terms were extracted from the mean flow field data and indicate that for a given ramp, the profile of turbulent shear stress normalized by the wall shear, versus distance from the surface, normalized by the local boundary thickness, is severely distored by the pressure gradient although it is apparently insensitive to local conditions.

Download or read book Measurements of a Supersonic Favorable pressure gradient Turbulent Boundary Layer with Heat Transfer written by Robert L. P. Voisinet and published by . This book was released on 1973 with total page 144 pages. Available in PDF, EPUB and Kindle. Book excerpt: The results of a detailed experimental investigation of the compressible turbulent boundary layer in a favorable-pressure-gradient flow are presented for zero, moderate and severe heat-transfer conditions. The studies were conducted on a flat nozzle wall at momentum thickness Reynolds numbers from 6,700 to 56,000 and at three wall-to-adiabatic-wall temperature ratios. An attempt was made to hold values of Clauser's pressure-gradient parameter constant. Complete profile measurements were taken with Pitot pressure probes and conical-equilibrium and fine-wire temperature probes. (Modified author abstract).

Download or read book Supersonic Turbulent Boundary layer Flows with Mass Injection Through Slots And or Porous Walls written by Alvin L. Murray and published by . This book was released on 1975 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: An implicit finite-difference method was used to solve the compressible boundary-layer equations, and to study the effects of mass transfer through porous plates, slots, and a combination of the two. The effects of the external pressure field were also included by using a global pressure interaction scheme. Two different eddy viscosity models were used for the slot and slot-porous combination cases: one was a two-layer model with inner and outer laws, and the other was a multi-layer model with as many as five separate layers. Results of the present method were compared with experimental data at a Mach number of 2.8. Comparisons of the skin friction reduction and Mach number profiles gave good to excellent agreement. Pressure interaction had little effect on the slot injection skin friction but increased the skin friction of the porous and slot-porous combination markedly.

Download or read book Turbulent Shear Layers in Supersonic Flow written by Alexander J. Smits and published by Springer Science & Business Media. This book was released on 2006-05-11 with total page 418 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.

Download or read book Fundamental Aspects of the Structure of Supersonic Turbulent Boundary Layers written by Alexander J. Smits and published by . This book was released on 1988 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Investigation of Supersonic Turbulent Boundary layer Separation on a Compression Ramp by an Integral Method written by and published by . This book was released on 1977 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Supersonic Turbulent Boundary Layer Growth Over Cooled Walls in Adverse Pressure Gradients written by C. E. KEPLER and published by . This book was released on 1962 with total page 94 pages. Available in PDF, EPUB and Kindle. Book excerpt: The characteristics of supersonic turbulent boundary layers on cooled surfaces having adverse pressure gradients were investigated to provide design information for hypersonic inlets. Tests were conducted at Mach numbers of 3 and 6 with values of wall temperature as low as 30% of the adiabatic recovery temperature. The adverse pressure gradients were generated by two-dimensional model including a circular-arc surface, an isentropic-compression surface, and an oblique shock generator. Velocity and temperature profiles through the boundary layer were obtained and the integral boundary layer parameters were evaluated along the surface. An analytical investigation was also conducted to provide a basis for evaluating the experimental results. It was found that cooled, turbulent boundary layers in adverse pressure gradients are thinner and less distorted than uncooled boundary layers, that the ratio of Stanton number to skin-friction coefficient is higher than the flat-plate value, and t at the total amount of heat removed is greater than that predicted by integrating local heat-transfer rates based on flat-plate conditions al ng the surface. (Author).

Download or read book Approximate Turbulent Boundary layer Development in Plane Compressible Flow Along Thermally Insulated Surfaces with Application to Supersonic tunnel Contour Correction written by Maurice Tucker and published by . This book was released on 1950 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt: As an application of the method, the contour correction of supersonic nozzles for the effects of boundary-layer development is discussed from the requirement of continuity of mass flow and from the requirement of expansion- and shock-wave elimination.

Download or read book Investigation of a Supersonic Turbulent Boundary Layer in an Adverse Pressure Gradient written by Eva Dillner Fields and published by . This book was released on 1977 with total page 252 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Numerical Simulation of Supersonic Turbulent Boundary Layer Flow Under the Influence of Mild Pressure Gradients written by Eric Thomas Fick and published by . This book was released on 1995 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Boundary Layer Transition at Supersonic Speeds written by E. R. Van Driest and published by . This book was released on 1961 with total page 108 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments carried out in the 12-inch supersonic wind tunnel to investigate the effect of three dimensional roughness elements (spheres) on boundary-layer transition on a 10-degree (apex angle) cone without heat transfer are described. The local Mach number for these tests was 2.71. The data show clearly that the minimum (effective) size of trip required to bring transition to its lowest Reynolds number varies power of the distance from the apex of the cone to the trip. Use of available data at other Mach numbers indicates that the Mach number influence for effective tripping is taken into account by a simple expression. Some remarks concerning the roughness variation for transition on a blunt body are made. Finally, a general criterion is introduced which gives insight to the transition phenomenon and anticipates effects of external and internal disturbances, Mach number transfer.