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EBookClubs

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Book Experimental Investigation of the Problem of Surface Roughness

Download or read book Experimental Investigation of the Problem of Surface Roughness written by H. Schlichting and published by . This book was released on 1937 with total page 604 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on the universal laws of turbulent velocity distribution at rough and smooth walls, there is in the present work presented a method that allows surface roughness tests and in particular, measurements on the roughness of ship surfaces to be carried out in a much simpler manner. The types of roughness investigated were in the form of flat, rough plates installed in a square-section rectangular channel, the other three walls always being smooth. Twenty-one plates of various roughness were investigated, the roughness elements being the following: spheres of diameter 0.41 and 0.21, respectively, spherical segments, cones, and "short" and "long" angles.

Book Aircraft Excrescence Drag

Download or read book Aircraft Excrescence Drag written by Alec David Young and published by . This book was released on 1981 with total page 159 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Correaltion of Full scale Drag Predictions with Flight Measurements on the C 141A Aircraft Phase 2 Wind Tunnel Test Analysis and Prediction Techniques Volume 1 Drag Predictions Wind Tunnel Data Analysis and Correlation

Download or read book Correaltion of Full scale Drag Predictions with Flight Measurements on the C 141A Aircraft Phase 2 Wind Tunnel Test Analysis and Prediction Techniques Volume 1 Drag Predictions Wind Tunnel Data Analysis and Correlation written by and published by . This book was released on 1974 with total page 174 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book An Analysis of Flight Test Data on the C 141A Aircraft

Download or read book An Analysis of Flight Test Data on the C 141A Aircraft written by and published by . This book was released on 1970 with total page 180 pages. Available in PDF, EPUB and Kindle. Book excerpt: This study comprises part of a research program to investigate the degree of correlation attainable between flight test measured airplane drag levels and the full scale drag that would be predicted on the basis of wind tunnel data.

Book Introduction to Aircraft Flight Mechanics

Download or read book Introduction to Aircraft Flight Mechanics written by Thomas R. Yechout and published by AIAA. This book was released on 2003 with total page 666 pages. Available in PDF, EPUB and Kindle. Book excerpt: Based on a 15-year successful approach to teaching aircraft flight mechanics at the US Air Force Academy, this text explains the concepts and derivations of equations for aircraft flight mechanics. It covers aircraft performance, static stability, aircraft dynamics stability and feedback control.

Book Full Scale Experiments Into the Use of Large Body Breakup Devices for Drag Reduction on Aircraft

Download or read book Full Scale Experiments Into the Use of Large Body Breakup Devices for Drag Reduction on Aircraft written by A. Bertelrud and published by . This book was released on 1984 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: A flight test was performed to explore the feasibility of using LEBU (Large-Eddy-Breakup) devices to reduce the drag of aircraft. Two geometrical shapes of ribbons were used, and the development of local skin friction was monitored downstream. The aircraft was a swept-wing attack aircraft, and the flights covered the entire subsonic; regime from M=0.92 down to stall conditions. Flight altitudes were 1, 4.5, 7 and 10 km to explore various combinations of angle of attack, Mach and Reynolds numbers. An essential part of the study was (1) to learn how to apply the devices, and (2) to explore the effects the devices might have on the flight characteristics of the aircraft -- for example, close to stall or when a shock was present on the wing. Some information was obtained concerning the turbulence characteristics downstream. A discussion of the 'downstream amplification effect' due to the drag at the device is provided.

Book Excrescence Drag on Aircraft Skin Repairs

Download or read book Excrescence Drag on Aircraft Skin Repairs written by Sanassee Laksham and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Book Temperature step Effects on Direct Measurement of Skin friction Drag

Download or read book Temperature step Effects on Direct Measurement of Skin friction Drag written by Robert L. P. Voisinet and published by . This book was released on 1977 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wall-temperature discontinuities can occur in skin-friction balance tests whenever a balance drag element is thermally insulated from the surrounding test surface. An experimental study was conducted to investigate the effects of such a temperature step on the local friction drag. A temperature step was produced by varying the temperature of the NSWC skin-friction-balance drag element above the temperature of the surrounding nozzle wall. Drag-element temperatures ranged from 100 K to 240 K with the surrounding wall maintained at a temperature of 89 K. Nominal Mach numbers were 2.9 and 4.9 over a unit Reynolds number range of 2.6 to 20 million per meter. The results show that the value of the measured shear stress is higher than the cold wall value for a drag element which is at a higher temperature than the surrounding wall temperature and the change in shear stress is proportional to the difference between the drag element and the surrounding wall temperatures. The data has been correlated and corrections to previously published skin-friction results are presented.

Book Experimental Investigation of the Effects of Viscosity on the Drag of Bodies of Revolution at a Mach Number of 1 5

Download or read book Experimental Investigation of the Effects of Viscosity on the Drag of Bodies of Revolution at a Mach Number of 1 5 written by Dean R. Chapman and published by . This book was released on 1947 with total page 92 pages. Available in PDF, EPUB and Kindle. Book excerpt: Summary: Tests were conducted to determine the effects of viscosity on the drag and base pressure characteristics of various bodies of revolution at a Mach number of 1.5. The models were tested both with smooth surfaces and with roughness added to evaluate the effects of Reynolds number for both laminar and turbulent boundary layers. The principal geometric variables investigated were after-body shape and length-diameter ratio. For most models, force tests and base pressure measurements were made over a range of Reynolds numbers, based on model length, from 0.6 million to 5.0 millions. Schlieren photographs were used to analyze the effects of viscosity on flow separation and shock-wave configuration near the base and to verify the condition of the boundary layer as deduced from force tests. The results are discussed and compared with theoretical calculations.

Book Local Skin Friction Coefficients and Boundary layer Profiles Obtained in Flight from the XB 70 1 Airplane at Mach Numbers Up to 2 5

Download or read book Local Skin Friction Coefficients and Boundary layer Profiles Obtained in Flight from the XB 70 1 Airplane at Mach Numbers Up to 2 5 written by David F. Fisher and published by . This book was released on 1973 with total page 76 pages. Available in PDF, EPUB and Kindle. Book excerpt: Boundary-layer and local friction data for Mach numbers up to 2.5 and Reynolds numbers up to 3.6 x 10 to the 8th power were obtained in flight at three locations on the XB-70-1 airplane: the lower forward fuselage centerline (nose), the upper rear fuselage centerline, and the upper surface of the right wing. Local skin friction coefficients were derived at each location by using (1) a skin friction force balance, (2) a Preston probe, and (3) an adaptation of Clauser's method which derives skin friction from the rake velocity profile. These three techniques provided consistent results that agreed well with the von Karman-Schoenherr relationship for flow conditions that are quasi-two-dimensional. At the lower angles of attack, the nose-boom and flow-direction vanes are believed to have caused the momentum thickness at the nose to be larger than at the higher angles of attack. The boundary-layer data and local skin friction coefficients are tabulated. The wind-tunnel-model surface-pressure distribution ahead of the three locations and the flight surface-pressure distribution ahead of the wing location are included.

Book Prediction of Turbulent Skin Friction for Two dimensional Rib type Surface Roughness Using a Discrete Element Approach

Download or read book Prediction of Turbulent Skin Friction for Two dimensional Rib type Surface Roughness Using a Discrete Element Approach written by Robert P. Taylor and published by . This book was released on 1985 with total page 38 pages. Available in PDF, EPUB and Kindle. Book excerpt: A discrete element model for turbulent flow over two-dimensional rib-type roughness is developed and validated. Surface roughness blockage effects and form drag are included as a constituent part of the differential equations. Separation and reattachment of the flow over rib roughness are identified as the dominant flow phenomena, and models are developed which incorporate the separated region geometry into the blockage. The form drag model is based on the pressure difference between the windward and leeward forces of the roughness. Predictions are compared with a variety of data sets. These comparisons indicate that the discrete element approach can be successfully applied for rib-type roughness. However, the model has a more narrow range of application for different surface geometries than the very broad range which has previously been demonstrated for three-dimensional, distributed roughness. Keywords: Two-dimensional roughness; Rib roughness; Boundary layer.