Download or read book Effects of Unit Reynolds Number Nose Bluntness and Roughness on Boundary Layer Transition written by J. Leith Potter and published by . This book was released on 1960 with total page 166 pages. Available in PDF, EPUB and Kindle. Book excerpt: Condtions encountered in the high Mach number flow regime are show to profoundly affect the longitudinal extent of the boundary layer from beginning to end of transition, the distribution of fluctuation energy in the laminar layer, and effectiveness of surface roughness in promoting transition. A critical layer of intense local energy fluctuations was found at all Mach numbers studied. The existence of such a critical layer is predicted by stability theory. Hot-wire surveys of the laminar, transitional, and turbulent boundary layers are presented to illustrate the critical layer in laminar flow and subsequent development into the transition process. The relation between boundary layer transition on flat plates and cones in supersonic flow is explored and a process for correcting data to account for leading edge bluntness is devised. On the basis of a comparison of data corrected for the effects of leading edge geometry, it is shown that the Reynolds umber of transition on a cone is three times that on a vanishingly thin flate plate. Close agreement between data from various wind tunnels is demonstrated. Study of the effect of finite leading edges yields significant illustrations of the influence of unit Reynolds number on boundary layer transition. A correlation of the effects of surface roughness on transition is achieved. This treatment includes two- and three-dimensional roughness in both subsonic and supersonic streams. At this time only zero pressure gradients have been studied. The entire range of movement of transition from its position with no roughness up to its reaching the roughness element is describable by the procedure give. Examples of application of the correlation results show excellent agreement with experimental data from a variety of sources. Implications concerning tripping hypersonic boundary layers are discussed.

Download or read book Effect of Unit Reynolds Number Nose Bluntness Angle of Attack and Roughness on Transition on a 5 Half angle Cone at Mach 8 written by P. Calvin Stainback and published by . This book was released on 1969 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Unit Reynolds Number Nose Bluntness and Roughness on Boundary Layer Transition written by J. Leith Potter and published by . This book was released on 1960 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt: This analysis consists of two parts. A technique is presented for measuring heat transfer rates on a model and for fixing the temperature distribution at a given value. The technique is applied to the particular case of turbulent heat transfer on a blunt body at a Mach number of 3.98. (Author).

Download or read book Effect of Nose Bluntness and Controlled Roughness on the Flow on Two Hypersonic Inlet Center Bodies Without Cowling at Mach 5 98 written by James M. Cubbage and published by . This book was released on 1965 with total page 66 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Mach Number Leading Edge Bluntness and Sweep on Boundary layer Transition on a Flat Plate written by Don W. Jillie and published by . This book was released on 1961 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Boundary layer Transition Study of Several Pointed Bodies of Revolution at Supersonic Speeds written by William A. Cassels and published by . This book was released on 1970 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Boundary-layer transition by the sublimation and impact-pressure techniques and force tests have been performed on three Haack-Adams bodies of revolution of fineness ratios 7, 10, and 13 at zero angle of attack for free-stream Mach numbers of 2.00, 2.75, and 4.63 and a range of Reynolds numbers based on model length of 6 to 15 X 10(to the 6 power) with and without a roughness strip. The grit method of inducing turbulence was found to provide for a nearly complete turbulent flow over the models at the lower Mach numbers and higher Reynolds numbers considered in this study while the amount of trip drag was less than 8 percent of the model drag with transition fixed. A method of interpreting sublimation data was discussed and used and the results compared well with the impact-pressure results.

Download or read book A Selected Listing of NASA Scientific and Technical Reports written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Division and published by . This book was released on 1970 with total page 962 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Technical Note written by and published by . This book was released on 1973 with total page 738 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Scientific and Technical Reports written by United States. National Aeronautics and Space Administration Scientific and Technical Information Division and published by . This book was released on 1970 with total page 966 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book NASA Scientific and Technical Reports and Publications for 1969 A Selected Listing written by United States. National Aeronautics and Space Administration. Scientific and Technical Information Division and published by . This book was released on 1970 with total page 956 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Viscous Drag Reduction written by C. Sinclair Wells and published by Springer. This book was released on 2013-12-20 with total page 497 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1972 with total page 520 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Critical Evaluation of Transition from Laminar to Turbulent Shear Layers with Emphasis on Hypersonically Traveling Bodies written by Mark Vladimir Morkovin (|d) and published by . This book was released on 1969 with total page 152 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Conference on Hypersonic Aircraft Technology written by and published by . This book was released on 1967 with total page 590 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book U S Government Research Reports written by and published by . This book was released on with total page 126 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Specific Types of Surface Roughness on Boundary layer Transition written by Laurence K. Loftin and published by . This book was released on 1946 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary: Tests were conducted with two typical low-drag airfoils of 90-inch chord to determine the effects of surface projections, grooves, and sanding scratches on boundary-layer transition. The Reynolds number at which a spanwise row of cylindrical projections would cause premature transition was determined for a range of Reynolds number from approximately 3 x 106 to 10 x 106. Data were obtained for projections of various sizes and chordwise locations on both low-drag airfoils. The results were analyzed on the assumption that the critical airfoil Reynolds number for a given projection was a function only of the local-flow conditions around the projection. This assumption neglected possible effects of tunnel turbulence, pressure gradient, boundary-layer Reynolds number, and the original extent of the laminar flow. The data correlated on the basis of this assumption within a range of critical airfoil Reynolds number of ±0.5 x 106 and within a range of projection height of ±0.002 inch. The tests of surface grooves and sanding scratches indicated that, for the range of Reynolds number investigated, the laminar boundary layer was much less sensitive to surface grooves and sanding scratches than to projections above the surface.

Download or read book A Comparison of Transition Reynolds Numbers from 12 in and 40 in Supersonic Tunnels written by C. J. Schueler and published by . This book was released on 1963 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: Transition Reynolds number measurements on a hollow cylinder in the von Karman Gas Dynamics Facility's 12-inch and 40-inch supersonic tunnels show that the highest transition Reynolds numbers were obtained in the 40-inch tunnel, although the variations with unit Reynolds number were the same at Mach numbers 3 to 5. The influence of nose bluntness in the 40-inch tunnel corresponds closely with the results obtained in the 12-inch tunnel.