Adaptive-wall Wind-tunnel Investigations PDF Download

Author: J. C. Erickson
Publisher:
ISBN:
Category :
Languages : en
Pages : 14

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Author: J. C Erickson (Jr)
Publisher:
ISBN:
Category :
Languages : en
Pages : 72

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The objective of this investigation was to continue the assessment of the Calspan perforated-wall, segmented-plenum adaptive-wall wind tunnel for flows in which the tunnel walls are supercritical. An important aspect of the investigation was the development of a static-pipe measuring technique for determining the normal velocity distributions. This technique was developed to overcome the limitations on the number of flow-angle probe measurements that could be made in the Calspan tunnel. The flow about a static pipe in the presence of model/wall-induced disturbances was analyzed within the framework of slender-body theory to give the relationship between differential pressure measurements across the pipe and the steam-wise derivative of the normal velocity at the pipe centerline.

Author: C. F. Lo
Publisher:
ISBN:
Category :
Languages : en
Pages :

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Author: Roland Gunther Berndt
Publisher:
ISBN:
Category :
Languages : en
Pages : 266

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Author: Marie H. Tuttle
Publisher:
ISBN:
Category : Wind tunnel walls
Languages : en
Pages : 60

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Author: Robert J. Vidal
Publisher:
ISBN:
Category : Aerodynamics, Transonic
Languages : en
Pages : 70

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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.

Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722937027
Category :
Languages : en
Pages : 156

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A series of adaptive wall ventilated wind tunnel experiments was carried out to demonstrate the feasibility of using the side wall pressure distribution as the flow variable for the assessment of compatibility with free air conditions. Iterative and one step convergence methods were applied using the streamwise velocity component, the side wall pressure distribution and the normal velocity component in order to investigate their relative merits. The advantage of using the side wall pressure as the flow variable is to reduce the data taking time which is one the major contributors to the total testing time. In ventilated adaptive wall wind tunnel testing, side wall pressure measurements require simple instrumentation as opposed to the Laser Doppler Velocimetry used to measure the velocity components. In ventilated adaptive wall tunnel testing, influence coefficients are required to determine the pressure corrections in the plenum compartment. Experiments were carried out to evaluate the influence coefficients from side wall pressure distributions, and from streamwise and normal velocity distributions at two control levels. Velocity measurements were made using a two component Laser Doppler Velocimeter system. Celik, Zeki and Roberts, Leonard Unspecified Center FLOW DISTRIBUTION; INFLUENCE COEFFICIENT; PRESSURE DISTRIBUTION; WALL PRESSURE; WIND TUNNEL TESTS; WIND TUNNEL WALLS; CONVERGENCE; FREE FLOW; LIFT; MACH NUMBER; PLENUM CHAMBERS; VELOCITY MEASUREMENT; VENTING...

Author: Marie H. Tuttle
Publisher:
ISBN:
Category : Wind tunnel walls
Languages : en
Pages : 44

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Author: National Aeronautics and Space Administration (NASA)
Publisher: Createspace Independent Publishing Platform
ISBN: 9781722935849
Category :
Languages : en
Pages : 112

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The first documented wind tunnel employing a flexible walled test section for the purpose of eliminating wall interference was constructed in England by the National Physical Laboratory (NPL) during the late 1930's. The tunnel was transonic and designed for two-dimensional testing. In an attempt to eliminate the top and bottom wall interference effects on the model NPL developed a strategy to adjust two flexible walls to streamlined shapes. This report covers an evaluation of the NPL wall adjustment strategy in a modern wind tunnel, e.g., the Transonic Self-Streamlining Wind Tunnel (TSWT) at the University of Southampton, England. The evaluation took the form of performance comparisons with other modern strategies which have been developed for use in, and proven in, the TSWT. Lewis, M. C. Unspecified Center ADAPTIVE CONTROL; HISTORIES; STREAMLINING; TRANSONIC WIND TUNNELS; WIND TUNNEL WALLS; AERODYNAMICS; AIRFOILS; UNITED KINGDOM; WIND TUNNEL TESTS...

Author: Marie H. Tuttle
Publisher:
ISBN:
Category : Interference (Aerodynamics)
Languages : en
Pages : 96

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