Download or read book An Experimental Study of Three dimensional Shock Wave Boundary Layer Interactions Generated by Sharp Fins written by Frank K. Lu and published by . This book was released on 1983 with total page 306 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Study of Three Dimensional Shock Wave Turbulent Boundary Layer Interaction Scaling of Sharp and Blunt Fin Induced Flowfields written by David S. Dolling and published by . This book was released on 1980 with total page 61 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study of three-dimensional (3-D) shock wave turbulent boundary layer interaction has been carried out. Interactions generated by fin models having sharp and hemi-cylindrically blunted leading edges have been studied. Tests have been made using incoming turbulent boundary layer varying in thickness in the ratio of about 4:1. Extensive surface property measurements have been made on the test surface on which the incoming boundary layer developed and on the fin itself. All of these tests were carried out at a nominal freestream Mach number of 3, a freestream unit Reynolds number of about 63 million per meter, and under approximately adiabatic wall conditions. The emphasis in the study reported on in this paper was on two main areas. First, to determine the key geometric and/or flow parameters controlling the overall scaling and characteristics of both blunt and sharp fin-induced interactions. Second, to identify the conditions under which both blunt and sharp fins induced interactions have the same local scale and characteristics. (Author).
Download or read book Experimental Investigation of Three Dimensional Shock Wave Turbulent Boundary Layer Interaction An Exploratory Study of Blunt Fin Induced Flows written by David S. Dolling and published by . This book was released on 1980 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study of three-dimensional (3-D) shock wave turbulent boundary layer interaction has been carried out. Interactions generated by fin models having sharp and hemi-cylindrically blunted leading edges have been studied. The emphasis in this particular study was twofold. First, the influence of incoming turbulent boundary layer thickness delta on the streamwise, spanwise and vertical scaling of the interaction was examined. Turbulent boundary layers varying in thickness from .127 cm (.05 in.) to 2.27 cm (0.89 in.) were used. In addition, a study has been conducted to examine the effects of the ratio D/delta (where D is the blunt fin leading edge diameter) on the interaction properties and scaling. Second, an investigation has been started to examine the unsteady shock wave-boundary layer structure and the resulting high frequency, large amplitude pressure fluctuations which occur ahead of and around the blunt fin leading edge. This is an area which in the past has been largely ignored, yet has important implications, since it is not clear that any mean surface property or flowfield measurements have any real physical significant. To date, measurement techniques and computer software have been developed and exploratory measurements made in the undisturbed turbulent boundary layer and also on the plane of symmetry ahead of the blunt fin.
Download or read book Three Dimensional Shock Wave and Turbulent Boundary Layer Interactions written by Seymour M. Bogdonoff and published by . This book was released on 1985 with total page 75 pages. Available in PDF, EPUB and Kindle. Book excerpt: An extensive experimental study of three-dimensional shock wave turbulent boundary layer interactions caused by shock generators defined solely by angles has been carried out at Mach 3. Sharp fins, sharp swept fins, swept wedges, and semi-cones have been used to generate a wide range of shock waves. The interaction of these waves with turbulent boundary layers has been investigated by surface flow visualization, mean surface static pressure distributions, flowfield surveys of total pressure and yaw, and several flowfield visualization techniques. Some exploratory high frequency surface pressure measurements have been carried out to evaluate the steadiness of these interactions. Scaling laws for both surface and flowfield features have been derived. Some limited studies were carried out at a Mach number of 2. A flowfield study has shown that the initial part of interactions caused by the same strength and geometrical shock wave generated by different shock generators are all similar. The 'footprints' of the interactions, as shown by surface flow visualization, can be categorized as approximately conical or cylindrical, and the boundaries between these two regions have been defined for both Mach 3 and Mach 2. There are still questions with regards to the detailed flowfield structures and physical mechanisms, but the three-dimensional interactions appeared to be less unsteady than that of two-dimensional separated flows.
Download or read book An Experimental Study Into the Scaling of an Unswept sharp fin generated Shock turbulent Boundary Layer Interaction written by William B. McClure and published by . This book was released on 1983 with total page 123 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental study was carried out of the three-dimensional shock wave/turbulent boundary layer flow-field generated by sharp fin with an unswept leading edge at a 10 deg angle-of-attack to the incoming flow. The model was mounted on and normal to either the tunnel floor or a horizontal flat plate. Both tests surfaces generated a fully developed, equillibrium tubulent boundary layer, with incoming thicknesses of 1.29 cm. and .45 cm., respectively. The incoming freestream was at a nominal Mach number of 2.95 and a Reynolds number of 6.3 x 10 to the 7th power/meter. All surfaces were near adiabatic wall temperature. The three objectives of this study were to learn more about the structure of this type of interaction, to examine the scaling of the resulting flow-field, and to obtain a detailed data set with which to compare numerical computations. The results show that the scaling of this type of interaction is dependent upon both local boundary layer thickness and freestream Reynold number.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 728 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Masters Theses in the Pure and Applied Sciences written by Wade H. Shafer and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 314 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, and disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1 957, starting its coverage of theses with the academic year 1955. Beginning with Volume 13, the printing and dissemination phases of the activity were transferred to University Microfilms/Xerox of Ann Arbor, Michigan, with the thought that such an arrangement would be more beneficial to the academic and general scientific and technical community. After five years of this joint undertaking we had concluded that it was in the interest of all con cerned if the printing and distribution of the volumes were handled by an interna tional publishing house to assure improved service and broader dissemination. Hence, starting with Volume 18, Masters Theses in the Pure and Applied Sciences has been disseminated on a worldwide basis by Plenum Publishing Cor poration of New York, and in the same year the coverage was broadened to include Canadian universities. All back issues can also be ordered from Plenum. We have reported in Volume 28 (thesis year 1 983) a total of 10,661 theses titles from 26 Canadian and 197 United States universities. We are sure that this broader base for these titles reported will greatly enhance the value of this important annual reference work. While Volume 28 reports theses submitted in-1983, on occasion, certain univer sities do report theses submitted in previous years but not reported at the time.
Download or read book Theoretical Investigation of Three Dimensional Shock Wave Turbulent Boundary Layer Interactions Part 2 written by and published by . This book was released on 1983 with total page 71 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of the research effort is the understanding of three-dimensional shock wave-turbulent boundary layer interactions. The approach uses the full mean compressible Navier-Stokes equations with turbulence incorporated through the algebraic turbulent eddy viscosity model of Baldwin and Lomax. During the present year of the research effort, the three-dimensional shock boundary layer interaction generated by a 10 deg sharp fin has been computed at Mach 3 for a Reynolds number 280000. These results, together with previous computations of the same configuration at Reynolds number = 930000, are compared with experimental data for pitot pressure and yaw angle. The agreement with the experimental data is good, and the theory accurately predicts the recovery of the boundary layer downstream of the interaction of Reynolds number = 280000. The computed flowfield is employed to analyze the structure of the 3-D interaction through contour plots of flow variables. Also, during the present year, the investigation of the 2-D turbulent supersonic compression corner at Mach 3 was completed. The relaxation modification to the Baldwin-Lomax model was found to yield reasonably accurate predictions of the upstream propagation of the surface for the Reynolds number range investigated. An additional computation at Mach 2 was performed, and the results were in general in agreement with the previous conclusions. (Author).
Download or read book Shock Wave Boundary Layer Interactions written by Holger Babinsky and published by Cambridge University Press. This book was released on 2011-09-12 with total page 481 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shock wave-boundary-layer interaction (SBLI) is a fundamental phenomenon in gas dynamics that is observed in many practical situations, ranging from transonic aircraft wings to hypersonic vehicles and engines. SBLIs have the potential to pose serious problems in a flowfield; hence they often prove to be a critical - or even design limiting - issue for many aerospace applications. This is the first book devoted solely to a comprehensive, state-of-the-art explanation of this phenomenon. It includes a description of the basic fluid mechanics of SBLIs plus contributions from leading international experts who share their insight into their physics and the impact they have in practical flow situations. This book is for practitioners and graduate students in aerodynamics who wish to familiarize themselves with all aspects of SBLI flows. It is a valuable resource for specialists because it compiles experimental, computational and theoretical knowledge in one place.
Download or read book An Experimental Study of the Sources of Fluctuating Pressure Loads Beneath Swept Shock Boundary Layer Interactions written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-30 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental research program providing basic knowledge and establishing a database on the fluctuating pressure loads produced on aerodynamic surfaces beneath three dimensional shock wave/boundary layer interactions is described. Such loads constitute a fundamental problem of critical concern to future supersonic and hypersonic flight vehicles. A turbulent boundary layer on a flat plate is subjected to interactions with swept planar shock waves generated by sharp fins at angle of attack. Fin angles from 10 to 20 deg at freestream Mach numbers of 3 and 4 produce a variety of interaction strengths from weak to very strong. Miniature Kulite pressure transducers flush-mounted in the flat plate are used to measure interaction-induced wall pressure fluctuations. The distributions of properties of the pressure fluctuations, such as their ring levels, amplitude distributions, and power spectra, are also determined. Measurements were made for the first time in the aft regions of these interactions, revealing fluctuating pressure levels as high as 160 dB. These fluctuations are dominated by low frequency (0-5 kHz) signals. The maximum ring levels in the interactions show an increasing trend with increasing interaction strength. On the other hand, the maximum ring levels in the forward portion of the interactions decrease linearly with increasing interaction sweep back. These ring pressure distributions and spectra are correlated with the features of the interaction flowfield. The unsteadiness of the off-surface flowfield is studied using a new, non-intrusive technique based on the shadow graph method. The results indicate that the entire lambda-shock structure generated by the interaction undergoes relatively low-frequency oscillations. Some regions where particularly strong fluctuations are generated were identified. Fluctuating pressure measurements are also made along the line of symmetry of an axisymmetric jet impinging upon a flat plate at an angle. This flow was chos...
Download or read book Characterization of the Flowfield Near a Wrap Around Fin at Supersonic Speeds written by Carl P. Tilmann and published by . This book was released on 1998 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: A wall-mounted semi-cylindrical model fitted with a single wrap- around in (WAF) has been investigated numerically and experimentally, with the objective of characterizing the mean and turbulent flowfield near a WAF in a supersonic flowfield. Numerical and experimental results are used to determine the nature of the flowfield and quantify the effects of fin curvature on the character of the flow near WAFs. This research has been motivated by the need to identify possible sources of a high-speed rolling moment reversal observed in sub-scale flight tests. Detailed mean flow and turbulence measurements were obtained in the AFIT Mach 3 wind tunnel using conventional probes and cross-wire hot-film anemometry at a series of stations upstream of and aft of the fin shock/boundary layer interaction. Hot-film anemometry results showed the turbulence intensity and Reynolds shear stress in the fuselage boundary layer to be far greater on the concave side of the fin than on the convex side. Mean flow was also obtained in the AFIT Mach 5 wind tunnel using conventional pressure probes. Numerical results were also obtained at the test conditions employing the algebraic eddy viscosity model of Baldwin and Lomax. Correlation with experimental data suggests that the calculations have captured the flow physics involved in this complicated flowfield. The calculations, corroborated by experimental results, indicate that a vortex exists in the fin/body juncture region on the convex side of the fin. This feature is not captured by the oft- used inviscid methods, and can greatly influence the pressure loading on the fin near the root.
Download or read book An Experimental Investigation of a Three dimensional Shock Wave boundary Layer Interaction written by Wei-Ming Keng and published by . This book was released on 1980 with total page 250 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Characterization and Flowfield Analysis of a Swept Shock Wave Boundary Layer Interaction written by Andrew Kyle Baldwin and published by . This book was released on 2021 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Shockwave boundary layer interactions (SBLI) occur on both internal and external surfaces and adversely affect both the structural and propulsive performance of high-speed flight vehicles operating in the trans/super/hypersonic flow regimes. In the absence of a comprehensive understanding of the flow physics associated with SBLI, the most common approach to mitigating the negative ramifications is structural over-design, often resulting in reduced aero-propulsion efficiencies and excessive cost. SBLI have been the subject of numerous experimental and numerical investigations focusing on simplified two-dimensional (2-D) canonical configurations derived from relatively complicated aircraft/turbomachinery components. A few recent studies have focused on addressing the knowledge gaps by examining component geometries that produce three-dimensional (3-D) SBLI and therefore a closer representation of real-world configurations. The current experimental investigation explores the viscous/inviscid interaction of an incoming supersonic turbulent boundary layer and a single, sharp unswept fin generated shockwave. This kind of SBLI is of keen interest to the high-speed aerodynamics community as the separated flow induces a strong crossflow component, giving rise to a highly 3-D flowfield. Although previous studies on 3-D SBLI have provided a substantial knowledge base, there are still a number of consequential questions pertaining to the flowfield topology and dynamical behavior that remain unanswered. First, what is the effect of Reynolds number on SBLI flow features, in particular, the length scales associated with the shock-induced separation region and its interaction with the shock generator (sharp-fin)? Second, what is the extent of facility dependence on the 3-D SBLI? Which, if any, component(s) of the unsteadiness is inherent to the interaction and which are facility dependent and therefore limit or bias the flowfield? Are the geometric and boundary layer constraints imposed by the size of the facility necessary for numerical simulations to ensure the proper development of scaling parameters as experiments shift from the laboratory scale to flight testing. Finally, how do the spatio-temporal scales associated with SBLI vary with the interaction strength? The main objective of the present experimental study is to answer the posed questions by conducting a detailed flowfield analysis of the sharp fin induced SBLI over a range of Reynolds numbers and interaction strengths. The research methodology involves high-fidelity experiments at the state-of-the-art wind tunnel facilities housed at the Florida Center for Advanced Aero-Propulsion at Florida State University and the data available from previously published literature. Cutting-edge global flowfield diagnostics allow for the full-field reconstruction of both skin friction (mean) and pressure (time-averaged/unsteady) underneath the single fin SBLI as the incoming Mach number (M[infinity] = 2 - 4), fin angle of attack ([alpha]F = 10° - 20°), and unit Reynolds number (Re/m 17 x 106 - 108 x 106) are parametrically varied. Reynolds number sweeps, spanning nearly an order of magnitude, illustrate that the interaction footprint is distinctly affected by the Reynolds number, with the effects being most prominent near the fin/surface junction and the outer edges of the interaction near the freestream boundary. The results indicate that the interaction flowfield becomes less receptive to Reynolds number variations as the Reynolds number continues to increase. This shrinking dependence indicates that there may be a point beyond which any further increases to the Reynolds number produce negligible differences in the flowfield id est Reynolds number independence. Identical surface oil flow and pressure measurements carried out in facilities of different scale/size compare favorably throughout the interaction region with Reynolds number based scaling. However, different incoming boundary layer thicknesses impose limitations on the extent of the inception region and the onset of finite fin effects. When investigating the mean skin friction between different scale facilities, the Reynolds number scaling could not be assessed due to limitations of the available data sets. An angular scaling was applied to enable proper inter-facility comparison between the conical regions of both identically matching and nominally equivalent interaction strength test cases. The results showed trends similar to those seen in the pressure measurements, with skin friction matching well between the facilities across the interaction with minor divergences in the near fin region, where viscous effects become more prominent. Simultaneously sampled high-speed pressure transducers and fast response PSP measurements allowed for a full-field investigation of the flow dynamics. The RMS pressure field highlights regions of increased unsteadiness along the interaction boundary, inviscid shock line and at/upstream of the fin tip vertex. Increased coherence levels indicate a communication mechanism is present between the inviscid shock and the interaction boundary. When compared with studies conducted in a smaller facility, findings of the current work are consistent in both the locations of increased unsteadiness and their respective magnitudes. In addition to illustrating the robustness of these dynamical features between differing size facilities, the current work identifies the presence of elevated levels of low-frequency content. The presence of this low-frequency content has been observed in investigations associated with 2-D SBLI, but has been absent in the 3-D SBLI studies conducted in smaller facilities. The present study has contributed significantly to a better understanding of swept 3-D SBLI, in particular, the role of Reynolds number and the size of facility on the interaction characteristics. The flowfield analysis has discovered the underlying physics associated with the fin induced SBLI. The high-fidelity experimental database generated will be very useful for the validation of numerical tools and the development of flight vehicle design guidelines.
Download or read book The Structure and Control of Three Dimensional Shock Wave Turbulent Boundary Layer Interactions written by and published by . This book was released on 1992 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The three year period covered in the subject report was a considerable shift from the previous years of work on shock wave turbulent boundary layer interactions. The earlier work concentrated on simple building block experiments and a search for fundamental understanding of the flow phenomena. In the subject research, most of the work on fundamentals for the simple configurations was stopped. The main emphasis for the first two years of the current program was on complex configurations and the final year was a close-out program on a new approach. The work on complex configurations was limited to two geometries which used the much studied single sharp fin interaction, Fig. 1, as the initial conditions. This shift in emphasis had two main purposes: (1) block experiments in more complex interactions required for applications and (2) to provide a more critical test of computation which, although giving the general characteristics for the building block experiments, did not give highly quantitative results. The primary activities for the first two years will be discussed in three major groupings: (1) and (2) Discussions of the two complex configurations, and (3) a description of the boundary layer conditions which are critical to the definition of the experiment and the check by computational fluid dynamics.
Download or read book Separated Flows and Jets written by Victor V. Kozlov and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 907 pages. Available in PDF, EPUB and Kindle. Book excerpt: Separated flows and jets are closely linked in a variety of applications. They are of great importance in various fields of fluid mechanics including vehicle efficiency, technical branches concerned with gas/liquid flows, atmospheric effects on various constructions, etc. Knowledge of the physics of separated flows and jets and the development of reliable control techniques are prerequisite for future progress in the field. These aspects were in focus during the IUTAM-Symposium which was held in Novosibirsk, 9-13 July, 1990. This volume contains a selection of papers presenting recent results of theoretical and numerical studies as well as experimental work on separated flows and jets. The topics include sub- and supersonic, laminar and turbulent separation as well as organized structures in separated flows and jets. The reader will find here the state of the art and major trends for research in this field of aero-hydrodynamics.
Download or read book Theoretical Investigation of Three Dimensional Shock Wave Turbulent Boundary Layer Interactions written by D. D. Knight and published by . This book was released on 1984 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of the research effort is the understanding of three-dimensional shock wave-turbulent boundary layer interactions. The approach uses the full mean compressible Navier-Stokes equations with turbulence incorporated through the algebraic turbulent eddy viscosity model of Baldwin and Lomax. This year's principle accomplishments are (1) the Baldwin-Lomax model was evaluated for a series of non-separated two-dimensional turbulent boundary layers. (2) the 3-D Navier-Stokes codes was rewritten innto CYBER 200 FORTRAN. (3) the computed results for the 3-D sharp fin alpha sub g = 10 deg were compared with the results of a separate calculation by C. Horstmann using the k-epsilon turbulence model, and the experimental data of McClure and Dolling. and (4) the 3-D sharp fin at alpha sub g =20 deg was computed, and the results compared with the available experimental data. The examination of the flowfield structure of the 3-D sharp fin at alphaa sub g = 20 deg was initiated. Originator supplied keywords include: High speed flows; Viscous-inviscid interactions; Shock-boundary layer interactions; Computational fluid dynamics; Navier-Stokes equations; and Turbulence.
Download or read book Theoretical Investigation of Three Dimensional Shock Wave Turbulent Boundary Layer Interactions written by Doyle D. Knight and published by . This book was released on 1982 with total page 50 pages. Available in PDF, EPUB and Kindle. Book excerpt: The focus of the research effort is the understanding of three-dimensional shock wave-turbulent boundary layer interactions. The approach uses the full mean compressible Navier-Stokes equations with turbulence incorporated through the algebraic turbulent eddy viscosity model of Baldwin and Lomax. During the present year of the research effort, the three-dimensional shock boundary layer interaction generated by a 10 deg sharp fin has been computed at Mach 3 for a Reynolds number 280000. These results, together with previous computations of the same configuration at Reynolds number = 930000, are compared with experimental data for pitot pressure and yaw angle. The agreement with the experimental data is good, and the theory accurately predicts the recovery of the boundary layer downstream of the interaction of Reynolds number = 280000. The computed flowfield is employed to analyze the structure of the 3-D interaction through contour plots of flow variables. Also, during the present year, the investigation of the 2-D turbulent supersonic compression corner at Mach 3 was completed. The relaxation modification to the Baldwin-Lomax model was found to yield reasonably accurate predictions of the upstream propagation of the surface for the Reynolds number range investigated. An additional computation at Mach 2 was performed, and the results were in general in agreement with the previous conclusions. (Author).
