Download or read book Reduction of Wind tunnel Wall Interference by Controlled Wall Flow written by Samuel Bernstein and published by . This book was released on 1976 with total page 68 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Reduction of Wind tunnel Wall Interference by Controlled Wall Flow written by Samuel Bernstein and published by . This book was released on 1976 with total page 70 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 Wind Tunnel Wall Correction written by B. F. R. Ewald and published by . This book was released on 1998 with total page 578 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report was compiled by an international team of wind tunnel wall correction experts. It presents the present state of the art in wind tunnel wall corrections with a special emphasis given to the description of modern wall correction methods based on Computational Fluid Dynamics. This AGARDograph was planned by the AGARD Fluid Dynamics Panel to be a modern sequel of the successful AGARDograph 109 "Subsonic Wind Tunnel Wall Corrections", which was published in 1966. AGARDogaph 109 is still valid and continues to be used to provide wall corrections in many wind tunnels. Nevertheless, in the thirty two years since the publication of AGARDograph 109, much work has been done on the subject, and the influence of the new tool of numerical fluid dynamics was so strong, that a sequel to AGARDograph 109 was considered to be necessary.
Download or read book Global Wall Interference Correction and Control for the National Wind Tunnel Complex Transonic Test Section written by and published by . This book was released on 1997 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: As part of the currently postponed National Wind Tunnel Complex (NWTC) program, a computational fluid dynamic (CFD) study of a large transport configuration was performed using the AEDC chimera-overset grid XAIR Euler code. Wall porosity, porosity control for the reduction of wall interference, correction approach, and the impact of reference point selection on wall interference at transonic conditions (Mach Number 0.85) were studied. These effects were computationally investigated using a clean wing model representative of the MD-11 aircraft which spanned 80 percent of the test section width. Global wall corrections were determined by a stream tube calculation of the interference flow field. Results of these computations showed that global corrections for Mach number at the 1/4 chord, 50-percent semi-span location with angle-of-attack correction based on matching wing lift gave very low interference. Investigation of control of porosity showed that very few zones were required to achieve superior results for global corrections and for model pressure distribution. Residual blockage gradient and flow-curvature effects are shown to be treatable by very small changes in side-wall divergence angle and model geometric changes that are equivalent to shearing the coordinate system aft of the wing-fuselage juncture.
Download or read book Calculation of Interference for a Porous Wall Wind Tunnel by the Method of Block Cyclic Reduction written by C. F. Lo and published by . This book was released on 1975 with total page 46 pages. Available in PDF, EPUB and Kindle. Book excerpt: The lift interference was calculated for a porous wall wind tunnel by a modified method of block cyclic reduction. This efficient, numerical method has indicated its accuracy by comparison with other available analytical and approximate solutions. A scheme is introduced to search for optimum wall configurations. The lift interference computed for an NACA 64-series finite airfoil in some optimum configurations has demonstrated the achievement of minimization of interference. The effect of test section length is also examined. (Author).
Download or read book Experiments for the Reduction of Wind Tunnel Wall Interference by Adaptive Wall Technology written by E. M. Kraft and published by . This book was released on 1979 with total page 43 pages. Available in PDF, EPUB and Kindle. Book excerpt: Experiments were conducted in the AEDC Aerodynamic Wind Tunnel (1T) to evaluate the applicability of adaptive-wall technology to reduce wall interference in a transonic wind tunnel. Data were obtained on a six-percent-blockage, two-dimensional, NACA 0012 airfoil section with two different, adaptable porous wall configurations. One configuration featured variable longitudinal control of the local hole angle and the other featured global porosity control. The experiments demonstrated that adaptive-wall techniques could be used to significantly reduce wall interference effects. Although neither wall configuration could be adjusted to duplicate the pressure distributions (calculated at the tunnel boundary control surface with adaptive-wall technology) to produce interference-free conditions, matching the pressure level upstream of the model and minimum pressure in the vicinity of the model adequately reduced the wall interference. One of the most effective means for matching these global parameters was plenum pressure adjustment; thus, some refinement may be obtained through segmented plena control. (Author).
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 Wind Tunnel Wall Interference written by E. H. Dowell and published by . This book was released on 1978 with total page 49 pages. Available in PDF, EPUB and Kindle. Book excerpt: A progress report on two aspects of theoretical research on improved understanding and reduction of wind tunnel wall interference is given. In part I, the compliant wall concept is studied for steady, two-dimensional supersonic flow. The compliant wall is modeled as a hinged plate with a torsional spring restraint. The combinations of flow dynamic pressure, wall geometry and wall compliance which lead to minimum wall interference with the flow over a lifting airfoil are identified. In part II, an improved theoretical model for flow over and through a slotted wall is constructed. The model takes into account streamline curvature in the direction of flow as well as flow through the slot perpendicular to the direction of flow. The theoretical relationship which is obtained between pressure differential across the slot and mass flow through the slot shows both the linear and quadratic regimes observed in experiments. Quantitative agreement with existing experimental data is also encouraging. (Author).
Download or read book An Investigation of Three dimensional Wall Interference in a Variable Porosity Transonice Wind Tunnel written by Travis W. Binion (Jr.) and published by . This book was released on 1974 with total page 88 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Methods for Assessing Wall Interference in the 2 by 2 foot Adaptive wall Wind Tunnel written by and published by . This book was released on 1986 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A Two Dimensional Adaptive Wall Test Section with Ventilated Walls in the Ames 2 By 2 Foot Transonic Wind Tunnel written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-02 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: The first tests conducted in the adaptive-wall test section of the Ames Research Center's 2- by 2-Foot Transonic Wind Tunnel are described. A procedure was demonstrated for reducing wall interference in transonic flow past a two-dimensional airfoil by actively controlling flow through the slotted walls of the test section. Flow through the walls was controlled by adjusting pressures in compartments of plenums above and below the test section. Wall interference was assessed by measuring (with a laser velocimeter) velocity distributions along a contour surrounding the model, and then checking those measurements for their compatibility with free-air far-field boundary conditions. Plenum pressures for minimum wall interference were determined from empirical influence coefficients. An NACA 0012 airfoil was tested at angles of attach of 0 and 2, and at Mach numbers between 0.70 and 0.85. In all cases the wall-setting procedure greatly reduced wall interference. Wall interference, however, was never completely eliminated, primarily because the effect of plenum pressure changes on the velocities along the contour could not be accurately predicted. Schairer, Edward T. and Lee, George and Mcdevitt, T. Kevin Ames Research Center...
Download or read book Research on Adaptive Wall Wind Tunnels written by Robert J. Vidal and published by . This book was released on 1978 with total page 70 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of this research was to investigate the utility of the Calspan self-correcting wind tunnel for minimizing or eliminating wall interference effects in two-dimensional transonic flows when shock waves from the test model extend to the tunnel walls. This report summarizes the experimental research performed with two-dimensional airfoils in the Calspan self-correcting wind tunnel and the theoretical research accomplished in support of the experiments. The experiments were performed with airfoil models having 4% and 6% solid blockage. The initial experiments with the 6%-blockage model were devoted to determining a practical mode of operation when shock waves from the model extend to the wall. The most practical model is to use wall control to obtain the desired distribution of longitudinal velocity components for subcritical walls. The Mach number is then increased and the wall control is readjusted, sequentially, until the desired test condition is achieved. At the high Mach numbers of interest, however, the available wall control was limited locally, and tunnel system changes were required. A method is reported for analyzing self-correcting wind tunnels with porous walls.
Download or read book NASA Technical Memorandum written by and published by . This book was released on 1986 with total page 74 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wall Interference in a Two dimensional flow Wind Tunnel with Consideration of the Effort of Compressibility written by H. Julian Allen and published by . This book was released on 1944 with total page 95 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book A New Method of Estimating Wind Tunnel Wall Interference in the Unsteady Two dimensional Flow written by National Aeronautical Establishment and published by . This book was released on 1983 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wall Interference in Wind Tunnels written by and published by . This book was released on 1982 with total page 228 pages. Available in PDF, EPUB and Kindle. Book excerpt:
