Download or read book Computations of Laminar Flow Control on Swept Wings as a Companion to Flight Test Research written by Richard G. Rhodes and published by . This book was released on 2010 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: The high cost of energy has resulted in a renewed interest in the study of reducing skin-friction drag in aeronautical applications. Laminar Flow Control (LFC) refers to any technique which alters the basic-state flow-field to delay transition from laminar to turbulent flow. Achieving fully laminar flow over a civilian transport wing will significantly reduce drag and fuel costs while increasing range and performance. Boundary-layer suction has proven to be an effective means of achieving laminar flow over an aircraft wing as demonstrated with the Northrop X-21 program; however, even with the savings in fuel, the high manufacturing and maintenance costs have discouraged the use of this technology. Recent work using threedimensional (3-D) spanwise-periodic distributed roughness elements (DREs) has shown great promise as a means of controlling the crossflow instability responsible for transition over a swept wing without the need for a complex suction system. The Texas A.

Download or read book Towards Laminar Flow on a Swept Wing written by Holger Kurz and published by . This book was released on 2016 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Natural Laminar Flow Flight Experiments on a Swept Wing Business Jet written by R. A. Rozendaal and published by . This book was released on 1986 with total page 104 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Further tests of a laminar flow swept wing with boundary layer control by suction written by R. R. Landeryou and published by . This book was released on 1966 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Summary of Laminar Flow Control Techniques for Aircraft written by Philip P. Antonatos and published by . This book was released on 1964 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Transition of the Laminar Boundary Layer on a Delta Wing with 74 Degree Sweep in Free Flight at Mach Numbers from 2 8 to 5 3 written by Gary T. Chapman and published by . This book was released on 1961 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Boundary layer Transition Results from the F 16XL 2 Supersonic Laminar Flow Control Experiment written by Laurie A. Marshall and published by . This book was released on 1999 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt: A variable-porosity suction glove has been flown on the F-16XL-2 aircraft to demonstrate the feasibility of this technology for the proposed High-Speed Civil Transport (HSCT). Boundary-layer transition data have been obtained on the titanium glove primarily at Mach 2.0 and altitudes of 53,000-55,000 ft. The objectives of this supersonic laminar flow control flight experiment have been to achieve 50- to 60-percent-chord laminar flow on a highly swept wing at supersonic speeds and to provide data to validate codes and suction design. The most successful laminar flow results have not been obtained at the glove design point (Mach 1.9 at an altitude of 50,000 ft). At Mach 2.0 and an altitude of 53,000 ft, which corresponds to a Reynolds number of 22.7 multiplied by 10[factor 6], optimum suction levels have allowed long runs of a minimum of 46-percent-chord laminar flow to be achieved. This paper discusses research variables that directly impact the ability to obtain laminar flow and techniques to correct for these variables.

Download or read book Aerodynamic Design for Swept wing Laminar Flow written by Michael Joseph Belisle and published by . This book was released on 2014 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt: This work describes and compares processes for swept-wing laminar flow control (SWLFC) aerodynamic design. It focuses on results obtained during the preliminary outer-mold-line (OML) design of the Subsonic Aircraft Roughness Glove Experiment (SARGE), a natural laminar flow and passive laminar flow control wing glove flight experiment funded by the NASA Environmentally Responsible Aviation initiative. The experiment seeks to raise the technology readiness level of the spanwise-periodic discrete roughness element (DRE) SWLFC technique for transition delay on a swept wing. Changes to the SARGE project requirements necessitated numerous redesigns that lead to design process insights and reinforced the value of proven methodologies. Optimization-based wing design methods are compared to traditional processes in the context of issues specific to SWLFC design. A refined traditional process incorporates the lessons learned during SARGE design excursions. As 3D effects are often significant at transonic Mach numbers, they should be included in the analysis as soon as practical when allowing for available computational tools. In the initial experimental feasibility and OML design, Euler computational fluid dynamics was used to produce a series of 2.5D SWLFC airfoils with boundary-layer stability and transition predicted using linear stability theory and the e[superscript N] method. Two wing gloves were lofted onto the Gulfstream-III host aircraft wing: TAMU-05-04, a straight loft using the TAMU2D-04 airfoils, and TAMU-06-05, an optimized revision used in the preliminary design review (PDR) of the SARGE experiment conducted in June 2012. The target pressure distribution for the TAMU-06-05 glove was developed using a graphical B-spline method. The SARGE PDR identified a few issues that need to be addressed in order to ensure a successful experiment, which includes isobar unsweep that adversely affects boundary layer stability for DRE control and potential flow separation at the inboard fairing. Using the refined process, an alternate planform is evaluated as a potential starting point to address these issues and is shown to be feasible. The electronic version of this dissertation is accessible from http://hdl.handle.net/1969.1/151655

Download or read book Two Experimental Supercritical Laminar flow control Swept wing Airfoils written by and published by . This book was released on 1987 with total page 28 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Natural Laminar Flow and Laminar Flow Control written by R.W. Barnwell and published by Springer Science & Business Media. This book was released on 2012-12-06 with total page 415 pages. Available in PDF, EPUB and Kindle. Book excerpt: Research on laminar flow and its transition to turbulent flow has been an important part of fluid dynamics research during the last sixty years. Since transition impacts, in some way, every aspect of aircraft performance, this emphasis is not only understandable but should continue well into the future. The delay of transition through the use of a favorable pressure gradient by proper body shaping (natural laminar flow) or the use of a small amount of suction (laminar flow control) was recognized even in the early 1930s and rapidly became the foundation of much of the laminar flow research in the U.S. and abroad. As one would expect, there have been many approaches, both theoretical and experimental, employed to achieve the substantial progress made to date. Boundary layer stability theories have been formu lated and calibrated by a good deal of wind tunnel and flight experiments. New laminar now airfoils and wings have been designed and many have been employed in aircraft designs. While the early research was, of necessity, concerned with the design of subsonic aircraft interest has steadily moved to higher speeds including those appropriate to planetary entry. Clearly, there have been substantial advances in our understanding of transition physics and in the development and application of transition prediction methodolo gies to the design of aircraft.

Download or read book Boundary Layer Transition in the Leading Edge Region of a Swept Cylinder in High Speed Flow written by Colin Phillip Coleman and published by . This book was released on 1998 with total page 212 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book A Laminar Flow Experiment in Flight on a Swept Wing A W 52 written by W.E. Gray and published by . This book was released on 1953 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Parametric Study on Laminar Flow for Finite Wings at Supersonic Speeds written by Joseph Avila Garcia and published by . This book was released on 1994 with total page 112 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Sweep Angle on the Boundary layer Stability Characteristics of an Untapered Wing at Low Speeds written by Frederick W. Boltz and published by . This book was released on 1960 with total page 86 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Issues Relating to Laminar Flow Control on the Leading edge of Swept Wings written by and published by . This book was released on 1995 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Boundary Layer and Flow Control written by G. V. Lachmann and published by Elsevier. This book was released on 2014-05-12 with total page 768 pages. Available in PDF, EPUB and Kindle. Book excerpt: Boundary Layer and Flow Control: Its Principles and Application, Volume 2 focuses on the layer of fluid in the immediate area of a bounding surface where the effects of viscosity are substantial. This book is organized into two main topics—boundary layer control for low drag, and shock-induced separation and its prevention by design and boundary layer control. It specifically discusses the nature of transition, effect of two-dimensional and isolated roughness on laminar flow, and progress in the design of low drag aerofoils. The onset of separation effects for aerofoils and wings, shock-induced separation for laminar boundary layers, and shock-induced separation for laminar boundary layers are also deliberated. This volume is recommended to physicists and specialists interested in boundary layer and flow control.

Download or read book Two Experimental Supercritical Laminar Flow Control Swept Wing Airfoils written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-24 with total page 24 pages. Available in PDF, EPUB and Kindle. Book excerpt: Two supercritical laminar-flow-control airfoils were designed for a large-chord swept-wing experiment in the Langley 8-Foot Transonic Pressure Tunnel where suction was provided through most of the model surface for boundary-layer control. The first airfoil was derived from an existing full-chord laminar airfoil by extending the trailing edge and making changes in the two lower-surface concave regions. The second airfoil differed from the first one in that it was designed for testing without suction in the forward concave region of the lower surface. Differences between the first airfoil and the one from which it was derived as well as between the first and second airfoils are discussed. Airfoil coordinates and predicted pressure distributions for the design normal Mach number of 0.755 and section lift coefficient of 0.55 are given for the three airfoils. Allison, Dennis O. and Dagenhart, J. Ray Langley Research Center NASA-TM-89073, NAS 1.15:89073 RTOP 505-60-21-02