Download or read book On Nonlinear Tollmien Schlichting vortex Interaction in Three Dimensional Boundary Layers written by Dominic A. R. Davis and published by . This book was released on 1993 with total page 32 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On Nonlinear Tollmien Schlichting Vortex Interaction in Three Dimensional Boundary Layers written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-09 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt: The instability of an incompressible three-dimensional boundary layer (that is, one with cross-flow) is considered theoretically and computationally in the context of vortex/wave interactions. Specifically the work centers on two low amplitude, lower-branch Tollmien-Schlichting waves which mutually interact to induce a weak longitudinal vortex flow; the vortex motion, in turn, gives rise to significant wave-modulation via wall-shear forcing. The characteristic Reynolds number is taken as a large parameter and, as a consequence, the waves' and the vortex motion are governed primarily by triple-deck theory. The nonlinear interaction is captured by a viscous partial-differential system for the vortex coupled with a pair of amplitude equations for each wave pressure. Three distinct possibilities were found to emerge for the nonlinear behavior of the flow solution downstream - an algebraic finite-distance singularity, far downstream saturation or far-downstream wave-decay (leaving pure vortex flow) - depending on the input conditions, the wave angles, and the size of the cross-flow. Davis, Dominic A. R. and Smith, Frank T. Glenn Research Center NCC3-233; RTOP 505-62-21...
Download or read book Nonlinear Tollmien Schlichting vortex Interaction in Boundary Layers written by P. Hall and published by . This book was released on 1988 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tollmien Schlichting Vortex Interactions in Compressible Boundary Layer Flows written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-13 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: The weakly nonlinear interaction of oblique Tollmien-Schlichting waves and longitudinal vortices in compressible, high Reynolds number, boundary-layer flow over a flat plate is considered for all ranges of the Mach number. The interaction equations comprise of equations for the vortex which is indirectly forced by the waves via a boundary condition, whereas a vortex term appears in the amplitude equation for the wave pressure. The downstream solution properties of interaction equations are found to depend on the sign of an interaction coefficient. Compressibility is found to have a significant effect on the interaction properties; principally through its impact on the waves and their governing mechanism, the triple-deck structure. It is found that, in general, the flow quantities will grow slowly with increasing downstream co-ordinate; i.e. in general, solutions do not terminate in abrupt, finite-distance 'break-ups'. Blackaby, Nicholas D. Unspecified Center NAS1-19480; RTOP 505-90-52-01...
Download or read book On the Interaction of Stationary Crossflow Vortices and Tollmien Schlichting Waves in the Boundary Layer on a Rotating Disc written by Institute for Computer Applications in Science and Engineering and published by . This book was released on 1989 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Strong Nonlinear Interaction of Tollmien Schlichting Waves and Taylor Goertler Vortices in Curved Channel Flow written by Institute for Computer Applications in Science and Engineering and published by . This book was released on 1988 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On Nonlinear Tollmien Schlichting vortex Interaction in Three Dimensional Boundary Layers written by Dominic A. R. Davis and published by . This book was released on 1993 with total page 30 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Interaction of Stationary Crossflow Vortices and Tollmien Schlichting Waves in the Boundary Layer on a Rotating Disc written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-10 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt: There are many fluid flows where the onset of transition can be caused by different instability mechanisms which compete among themselves. The interaction is considered of two types of instability mode (at an asymptotically large Reynolds number) which can occur in the flow above a rotating disc. In particular, the interaction is examined between lower branch Tollmien-Schlichting (TS) waves and the upper branch, stationary, inviscid crossflow vortex whose asymptotic structure has been described by Hall (1986). This problem is studied in the context of investigating the effect of the vortex on the stability characteristics of a small TS wave. Essentially, it is found that the primary effect is felt through the modification to the mean flow induced by the presence of the vortex. Initially, the TS wave is taken to be linear in character and it is shown (for the cases of both a linear and a nonlinear stationary vortex) that the vortex can exhibit both stabilizing and destabilizing effects on the TS wave and the nature of this influence is wholly dependent upon the orientation of this latter instability. Further, the problem is examined with a larger TS wave, whose size is chosen so as to ensure that this mode is nonlinear in its own right. An amplitude equation for the evolution of the TS wave is derived which admits solutions corresponding to finite amplitude, stable, traveling waves. Bassom, Andrew P. and Hall, Philip Unspecified Center...
Download or read book On Strongly Nonlinear Vortex wave Interactions in Boundary layer Transition written by Philip Hall and published by . This book was released on 1989 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Tollmien Schlichting vortex Interactions in Compressible Boundary Layer Flows written by Nicholas D. Blackaby and published by . This book was released on 1993 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book IUTAM Symposium on Nonlinear Instability and Transition in Three Dimensional Boundary Layers written by Peter W. Duck and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 458 pages. Available in PDF, EPUB and Kindle. Book excerpt: Most fluid flows of practical importance are fully three-dimensional, so the non-linear instability properties of three-dimensional flows are of particular interest. In some cases the three-dimensionality may have been caused by a finite amplitude disturbance whilst, more usually, the unperturbed state is three-dimensional. Practical applications where transition is thought to be associated with non-linearity in a three- dimensional flow arise, for example, in aerodynamics (swept wings, engine nacelles, etc.), turbines and aortic blood flow. Here inviscid `cross-flow' disturbances as well as Tollmien-Schlichting and Görtler vortices can all occur simultaneously and their mutual non-linear behaviour must be understood if transition is to be predicted. The non-linear interactions are so complex that usually fully numerical or combined asymptotic/numerical methods must be used. Moreover, in view of the complexity of the instability processes, there is also a growing need for detailed and accurate experimental information. Carefully conducted tests allow us to identify those elements of a particular problem which are dominant. This assists in both the formulation of a relevant theoretical problem and the subsequent physical validation of predictions. It should be noted that the demands made upon the skills of the experimentalist are high and that the tests can be extremely sophisticated - often making use of the latest developments in flow diagnostic techniques, automated high speed data gathering, data analysis, fast processing and presentation.
Download or read book Nonlinear Development of Gortler and Crossflow Vortices and Gortler Tollmien Schlichting Wave Interaction written by M. R. Malik and published by . This book was released on 1990 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: The problem of nonlinear development of Goertler vortices on a curved wall is studied within the framework of incompressible Navier-Stokes equations which are solved by a Fourier-Chebyshev spectral method. The results show that higher harmonics grow due to nonlinear effects; however, most of the energy remains in the fundamental mode. The computed flow field in the presence of a Goertler vortex is in qualitative agreement with the experimental data. The interaction of the Goertler vortex with a two-dimensional Tollmien-Schlichting wave is also studied and it is shown that the Tollmien-Schlichting wave grows faster than its linear theory growth rate when the amplitude of the Goertler vortex is sufficiently large. Due to nonlinear effects this interaction further leads to the development of oblique waves with spanwise wavelength equal to the Goertler vortex wavelength. The numerical method is also applied to study the nonlinear development of a stationary crossflow vortex in a Falkner-Skan-Cooke boundary layer. The crossflow vortex develops in a manner similar to that found earlier for rotating disk flow. The fundamental and the higher harmonics all tend to saturate when the integration is carried to large amplitudes. The computed velocity distribution clearly shows the emergence of the superharmonic which, however, does not dominate the fundamental mode. The Falkner-Skan-Cooke flow, modulated by the presence of the crossflow vortex, is found to be subject to a new secondary instability with large growth rates. (JHD).
Download or read book On the Generation of Mean Flows by the Interaction of Goertler Vortices and Tollmien Schlichting Waves in Curved Channel Flows written by and published by . This book was released on 1988 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Nonlinear Instability of Nonparallel Flows written by S.P. Lin and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 479 pages. Available in PDF, EPUB and Kindle. Book excerpt: The IUTAM Symposium on Nonlinear Instability of Nonparallel Flows was held at Clarkson University, Potsdam, NY 13699-5725, USA from 26 to 31 July 1993. It consisted of 9 general speeches, 35 lectures and 15 poster-seminar presentations. The papers were grouped in fairly focused sessions on boundary layers, shear flows, vortices, wakes, nonlinear waves and jets. The symposium was fol lowed by a workshop in which the subject matter discussed was sum marized and some further work for future investigation was recom mended. The highlights of the workshop will be reported elsewhere. In this book many of the papers that describe the ideas presented at the symposium are collected to provide a reference for researchers in charting the future course of their studies in the area of nonlinear instability of nonparallel flows. The papers in this book are grouped under the following headings: • Boundary layers and shear flows • Compressibility and thermal effects • Vortices and wakes • Nonlinear waves and jets In the lead paper ofthis book M. E. Goldstein describes an asymp totic theory of nonlinear interaction between two spatially growing oblique waves on nonparallel boundary and free-shear layers. The wave interaction originates from the nonlinear critical layer and is responsive to weakly nonparallel effects. The theory results in a sys tem of integral differential equations which appear to be relevant near the upper branch of the neutral curve.
Download or read book The Fully Nonlinear Development of G rtler Vortices in Growing Boundary Layers written by Philip Hall and published by . This book was released on 1987 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Taylor Goertler Instabilities of Tollmien Schlichting Waves and Other Flows Governed by the Interactive Boundary Layer Equations written by Institute for Computer Applications in Science and Engineering and published by . This book was released on 1985 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book On the Secondary Instability of Taylor Goertler Vortices to Tollmien Schlichting Waves in Fully developed Flows written by James Bennett and published by . This book was released on 1986 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:
