Download or read book Boundary Interference at Subsonic Speeds in Wind Tunnels with Ventilated Walls written by M. Pindzola and published by . This book was released on 1969 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Equations and charts as obtained by theoretical analyses are presented for the evaluation of corrections which must be applied to test data as obtained from wind tunnels because of the presence of the test section boundaries. Results are presented for two-dimensional, circular, and rectangular tunnels with boundaries of the completely closed, completely open, slotted, or perforated variety. Interference factors accounting for the direct effects of model and wake blockage on the longitudinal velocity and of model lift on the upwash velocity are enumerated. In addition, consideration is given to the variation of the longitudinal and vertical velocity components along the tunnel axis leading to buoyancy and streamline-curvature corrections. (Author).
Download or read book An Integral Equation Method for Boundary Interference in a Perforated wall Wind Tunnel at Transonic Speeds written by E. M. Kraft and published by . This book was released on 1976 with total page 84 pages. Available in PDF, EPUB and Kindle. Book excerpt: The wind tunnel boundary interference at transonic speeds on a thin airfoil in a two-dimensional perforated-wall wind tunnel was determined. The interference was found by applying an integral equation method to the nonlinear transonic small disturbance equation including embedded supersonic regions with shock waves. The kernels of the ensuing integral equation were replaced by series approximations, and the integrals were evaluated in closed form. The iterative technique used to calculate the interference from the integral equation method is shown to converge rapidly, and the computing time for the integral equation method is typically an order of magnitude less than present numerical methods. As a special case, the integral equation method for a thin airfoil in free air was also examined. It was found that the introduction of a novel influence function yields, for the first time, a self-contained integral equation for a lifting airfoil. In addition, a systematic study of the classical assumption used to simplify the integral equation shows that the integral method can provide solutions in good agreement with results from the numerical methods.
Download or read book Analytical Study of Ventilated Wind Tunnel Boundary Interference on V STOL Models Including Wake Curvature and Decay Effects written by E. M. Kraft and published by . This book was released on 1974 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt: The wind tunnel boundary interference on a V/STOL model is calculated in a rectangular test section with solid vertical walls and ventilated (perforated or slotted) horizontal walls. The interference is found by applying the small perturbation theory of an incompressible fluid to the boundary value problem. The theory uses an image method in addition to Fourier transforms with an equivalent homogeneous boundary condition on the ventilated wall. The mathematical representation of the V/STOL model accounts for the curvature and decay of the wake. The assumption of a constant wake strength produces a paradox in that the maximum value of the interference factors increases as the initial jet velocity decreases. The most significant aspect of the analysis shows that nonlinear cross-flow effects at the tunnel boundary are important in the V/STOL case, and a quasi-linear approximation to these effects is introduced into the solution providing good agreement with experimental data.
Download or read book Wind Tunnel Wall Interference January 1980 May 1988 written by Marie H. Tuttle and published by . This book was released on 1988 with total page 96 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wall Interference in Wind Tunnels with Slotted and Porous Boundaries at Subsonic Speeds written by Barrett Stone Baldwin and published by . This book was released on 1953 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: Linearized compressible-flow analysis is applied to the study of wind-tunnel-wall interference for subsonic flow in either two-dimensional or circular test sections having slotted or porous walls. Expressions are developed for evaluating blockage and lift interference.
Download or read book An Experimental Investigation of Boundary Interference at Subsonic Speeds in a Two dimensional Perforated wall Wind Tunnel written by Gerald Edwin Matyk and published by . This book was released on 1973 with total page 276 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Investigation of Several Slotted Wind Tunnel Wall Configurations with a High Disk Loading V STOL Model written by Travis W. Binion and published by . This book was released on 1971 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: The investigation reported herein is the experimental portion of a unified theoretical and experimental search for a slotted wind tunnel wall configuration with minimal interference for conventional and V/STOL models. It is shown that theory and experiment are in excellent agreement for the classical case provided an appropriate expression is used to relate the wall geometry to the boundary condition. Classical data correction equations are not appropriate for the V/STOL case, however. An additional term, not predicted by theory, is needed to account for changes in the jet wake. Geometric parameters which influence the wall interference quantities are indicated. Wall configurations are shown which will produce interference-free force data to a jet-to-free-stream velocity ratio of 4.5. (Author).
Download or read book NASA Technical Note written by and published by . This book was released on 1973 with total page 588 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 1992 with total page 80 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Boundary Interference in a Rectangular Wind Tunnel with Perforated Walls written by C. F. Lo and published by . This book was released on 1970 with total page 53 pages. Available in PDF, EPUB and Kindle. Book excerpt: The boundary interference at subsonic speeds is presented for rectangular wind tunnels with perforated walls. The point-matching method is used for the analysis with an equivalent homogeneous boundary condition at the perforated walls. Numerical results are given for rectangular wind tunnels having various porosities and height-to-width ratios of 1.0, 0.8, and 0.5. (Author).
Download or read book NASA Technical Paper written by United States. National Aeronautics and Space Administration and published by . This book was released on 1990 with total page 492 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Application of Linearized Transonic Theory to Tunnel Blockage Interference written by C. F. Lo and published by . This book was released on 1974 with total page 34 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 456 pages. Available in PDF, EPUB and Kindle. Book excerpt: Lists citations with abstracts for aerospace related reports obtained from world wide sources and announces documents that have recently been entered into the NASA Scientific and Technical Information Database.
Download or read book Two Dimensional Aerodynamic Interference Effects on Oscillating Airfoils with Flaps in Ventilated Subsonic Wind Tunnels written by Joseph Fromme and published by . This book was released on 1979 with total page 156 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Numerical Method of Calculating the Boundary induced Interference in Slotted of Perforated Wind Tunnels of Rectangular Cross Section written by James D. Keller and published by . This book was released on 1971 with total page 26 pages. Available in PDF, EPUB and Kindle. Book excerpt: A numerical method is presented for calculating the boundary-induced interference at subsonic speeds in wind tunnels of rectangular cross section with slotted or perforated walls. The slot width or wall porosity can vary throughout the test section. The interference can be computed at any point in the test section. The model can be any configuration and can be located anywhere in the test section. Several examples are given, and comparison is made with other methods were available.
Download or read book An Experimental Investigation of Boundary Interference at Subsonic Speeds in a Two dimensional Perforated wall Wind Tunnel written by Gerald Edwin Matyk and published by . This book was released on 1973 with total page 138 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1986 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
