Download or read book The Effect of Roughness Applied on an Airfoil at Or Near the Leading Edge at Low Reynolds Numbers written by Diane Ruth Bloch and published by . This book was released on 1986 with total page 546 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book The Effects of Roughness at High Reynolds Numbers on the Lift and Drag Characteristics of Three Thick Airfoils written by Frank T. Abbott and published by . This book was released on 1944 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: In connection with studies of airfoils applicable to large high-speed aircraft, the effects of roughness on three 22-percent-thick airfoils were investigated. The tests were made over a range of Reynolds numbers from about 6,000,000 to 26,000,000 for the airfoils smooth and with roughness strips applied to the surfaces. The results indicated that for the roughened models the scale effect was generally favorable.
Download or read book A Effects of Reynolds Number and Leading edge Roughness on Lift and Drag Characteristics of the NACA 653 418 written by John H. Quinn and published by . This book was released on 1945 with total page 7 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tests were made in the Langley two-dimensional low-turbulence tunnels of an NACA 653-418, a = 1.0 airfoil section with roughness in the form of carborundum grains applied to the leading edge. Roughness grains having average diameters of 0.0003 and 0.0007 airfoil chord were applied to the leading edge of the wing, and lift and drag measurements were made for a range of Reynolds numbers from 0.23 to 3.0 x 106. From a comparison of data obtained in the present tests with data obtained in tests of the smooth wing, marked reductions in maximum lift coefficient were found to be caused by the roughness throughout the test range of Reynolds number. The drag coefficient at the design lift coefficient increased sharply and the lift-curve slope decreased rapidly at a critical Reynolds number that depended upon the size of the carborundum grains. This critical Reynolds number occurred at approximately 0.50 and 0.70 x 106 for the 0.0003- and the 0.0007-chord-diameter roughness grains, respectively. With roughness, a decrease in maximum lift coefficient as great as 0.2, a decrease in lift-curve slope of 0.028, and an increase in drag coefficient at the design lift coefficient of 0.0007 were observed at a Reynolds number of 1.0 x 106. For the smooth wing at the same Reynolds number, the maximum lift coefficient was 1.19, the lift-curve slope was 0.116, and the drag coefficient was 0.0077. At Reynolds numbers greater than 1.0 x 106, the scale effect on the lift and drag characteristics of the section with both degrees of roughness was generally in the same direction as the effect on the lift and drag characteristics of the smooth airfoil.
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 NASA Technical Memorandum written by and published by . This book was released on 1988 with total page 700 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 414 pages. Available in PDF, EPUB and Kindle. Book excerpt: Masters Theses in the Pure and Applied Sciences was first conceived, published, SIld disseminated by the Center for Information and Numerical Data Analysis and Synthesis (CINDAS) * at Purdue University in 1957, 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 and broader dissemination. tional publishing house to assure improved service 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 30 (thesis year 1985) a total of 12,400 theses titles from 26 Canadian and 186 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.
Download or read book Wartime Report written by and published by . This book was released on 194? with total page 660 pages. Available in PDF, EPUB and Kindle. Book excerpt: Reproductions of reports, some declassified, of research done at Langley Memorial Aeronautical Laboratory during World War II. The order of reports does not represent when they were chronologically issued. Reference to the original version of each report is included.
Download or read book Technical Note National Advisory Committee for Aeronautics written by United States. National Advisory Committee for Aeronautics and published by . This book was released on 1947 with total page 1106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report written by United States. National Advisory Committee for Aeronautics and published by . This book was released on 1957 with total page 160 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Annual Report of the National Advisory Committee for Aeronautics written by United States. National Advisory Committee for Aeronautics and published by . This book was released on 1948 with total page 692 pages. Available in PDF, EPUB and Kindle. Book excerpt: Includes the Committee's Reports no. 1-1058, reprinted in v. 1-37.
Download or read book Wartime Report written by United States. National Advisory Committee for Aeronautics and published by . This book was released on with total page 362 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Report written by and published by . This book was released on 1957 with total page 1180 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NACA Wartime Report written by United States. National Advisory Committee for Aeronautics and published by . This book was released on with total page 716 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Technical Note written by and published by . This book was released on 1947 with total page 566 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Viscous Drag Reduction in Boundary Layers written by and published by AIAA. This book was released on 1990 with total page 542 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by and published by . This book was released on 1981 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Paper written by United States. National Aeronautics and Space Administration and published by . This book was released on 1978 with total page 802 pages. Available in PDF, EPUB and Kindle. Book excerpt:
