Download or read book Wall Interference and Boundary Simulation in a Transonic Wind Tunnel with a Discretely Slotted Test Section written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-07-17 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computational simulation of a transonic wind tunnel test section with longitudinally slotted walls is developed and described herein. The nonlinear slot model includes dynamic pressure effects and a plenum pressure constraint, and each slot is treated individually. The solution is performed using a finite-difference method that solves an extended transonic small disturbance equation. The walls serve as the outer boundary conditions in the relaxation technique, and an interaction procedure is used at the slotted walls. Measured boundary pressures are not required to establish the wall conditions but are currently used to assess the accuracy of the simulation. This method can also calculate a free-air solution as well as solutions that employ the classical homogeneous wall conditions. The simulation is used to examine two commercial transport aircraft models at a supercritical Mach number for zero-lift and cruise conditions. Good agreement between measured and calculated wall pressures is obtained for the model geometries and flow conditions examined herein. Some localized disagreement is noted, which is attributed to improper simulation of viscous effects in the slots. Al-Saadi, Jassim A. Langley Research Center...
Download or read book Wall Interference and Boundary Simulation in a Transonic Wind Tunnel with a Discretely Slotted Test Section written by Jassim A. Al-Saadi and published by . This book was released on 1993 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transonic Flow at a Slotted Test Section Wall written by Sune B. Berndt and published by . This book was released on 1976 with total page 16 pages. Available in PDF, EPUB and Kindle. Book excerpt: The objective of the now concluded research has been to make possible the accurate computation of slotted walls interference in transonic wind-tunnels. This has been achieved through studying experimentally the flow at and through slotted walls and through developing theoretical models for such flows. The final result is a homogenous wall boundary condition to be used when computing numerically the three-dimensional transonic flow around a wind-tunnel model, be it to determine the interference from the test-section walls or to adjust the wall parameters for zero interference. The boundary condition is of rather general applicability, admitting great freedom in the choice of slot geometry and facilitating the inclusion of corrections for viscous effects, such as disclosed by the experiments. (Author).
Download or read book Computer Simulation of a Wind Tunnel Test Section with Discrete Finite length Wall Slots written by and published by . This book was released on 1986 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt: A computer simulation of a slotted wind tunnel test section which includes a discrete, finite-length wall slot representation with plenum chamber constraints and accounts for the nonlinear effects of the dynamic pressure of the slot outflow jet and of the low energy of slot inflow air was developed. The simulation features were selected to be those appropriate for the intended subsequent use of the simulation in a wall interference assessment procedure using sparsely located wall pressure measurements. It is demonstrated that accounting for slot discreteness is important in interpreting wall pressure measured between slots, and that accounting for nonlinear slot flow effects produces significant changes in tunnel-induced velocity distributions and, in particular, produces a longitudinal component of tunnel-induced velocity due to model lift. A characteristic mode of tunnel flow interaction with constraints imposed by the plenum chamber and diffuser entrance is apparent in simulation results and is derived analytically through a simplified analysis.
Download or read book Computer Simulation of a Wind Tunnel Test Section with Discrete Finite length Wall Slots written by William B. Kemp and published by . This book was released on 1986 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Transonic Wind Tunnel Testing written by B. H. Goethert and published by . This book was released on 2007 with total page 420 pages. Available in PDF, EPUB and Kindle. Book excerpt: Numerous aspects of transonic aerodynamics include wall interference corrections in conventional wind tunnels, subsonic flow in a variety of wind tunnels, and test results from transonic wind tunnels. 1961 edition.
Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1994 with total page 892 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 Direct Validation of the Wall Interference Correction System of the Ames 11 Foot Transonic Wind Tunnel written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-05-31 with total page 64 pages. Available in PDF, EPUB and Kindle. Book excerpt: Data from the test of a large semispan model was used to perform a direct validation of a wall interference correction system for a transonic slotted wall wind tunnel. At first, different sets of uncorrected aerodynamic coefficients were generated by physically changing the boundary condition of the test section walls. Then, wall interference corrections were computed and applied to all data points. Finally, an interpolation of the corrected aerodynamic coefficients was performed. This interpolation made sure that the corrected Mach number of a given run would be constant. Overall, the agreement between corresponding interpolated lift, drag, and pitching moment coefficient sets was very good. Buoyancy corrections were also investigated. These studies showed that the accuracy goal of one drag count may only be achieved if reliable estimates of the wall interference induced buoyancy correction are available during a test.Ulbrich, Norbert and Boone, Alan R.Ames Research CenterCORRECTION; TRANSONIC WIND TUNNELS; WALL FLOW; WIND TUNNEL TESTS; AERODYNAMIC INTERFERENCE; SLOTTED WIND TUNNELS; INTERPOLATION; MACH NUMBER; PITCHING MOMENTS; LIFT; BOUNDARY CONDITIONS; ACCURACY; BUOYANCY
Download or read book Approximation of the Spanwise Distribution of Wind tunnel boundary Interference on Lift of Wings in Rectangular Perforated wall Test Sections written by Ray H. Wright and published by . This book was released on 1968 with total page 42 pages. Available in PDF, EPUB and Kindle. Book excerpt: An approximation method has been developed for calculating the spanwise distribution of wind-tunnel-boundary upwash interference on lift of wings in rectangular perforated-wall test sections. This method is applied to square test sections with an assumed effective permeability constant of 0.6. A problem of considerable difficulty in practical application of the method presented is the estimation of an effective permeability constant. Because of the variation of the upwash interference with Mach number and of the influence of boundary layer on the effective permeability factor, the boundary interference in a perforated-wall wind-tunnel test section at high subsonic Mach numbers is likely to be of the nature of that in an open-throat tunnel.
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 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 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 Test Techniques written by Colin Britcher and published by Academic Press. This book was released on 2023-10-20 with total page 672 pages. Available in PDF, EPUB and Kindle. Book excerpt: Wind Tunnel Test Techniques: Design and Use at Low and High Speeds with Statistical Engineering Applications provides an up-to-date treatment of the topic. Beginning with a brief history of wind tunnels and its types and uses, the book goes on to cover subsonic, supersonic and hypersonic wind tunnel design and construction, calibration, boundary corrections, flow quality assessment, pressure surveys, and dynamic testing. It also focuses on wind tunnel facilities, making it useful for both the designer and operator. Engineers and graduate students in aerospace, automotive and similar programs will find this book useful in their work with experimental aerodynamics, gas dynamics, facility design and performance. - Deals with a broad range of flow speeds in wind tunnels, from low speed to high speed - Provides a discussion of similarity laws as well as material on statistical analysis - Includes coverage on facility-to-facility and facility-to-CFD correlation - Presents advanced topics such as cryogenic wind tunnels, ground simulation in automotive testing, and propulsion testing
Download or read book Wall Interference in Wind Tunnels written by North Atlantic Treaty Organization. Advisory Group for Aerospace Research and Development and published by . This book was released on 1982 with total page 242 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Wind Tunnel Wall Interference in V STOL and High Lift Testing written by Marie H. Tuttle and published by . This book was released on 1986 with total page 58 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Description and Evaluation of an Interference Assessment Method for a Slotted wall Wind Tunnel written by William B. Kemp and published by . This book was released on 1991 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
