Download or read book Further Investigations of Adaptive Wall Wind Tunnels written by J. C Erickson (Jr) and published by . This book was released on 1980 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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.
Download or read book Adaptive wall Wind tunnel Investigations written by J. C. Erickson and published by . This book was released on 1981 with total page 14 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Investigation of Adaptive Wall Wind Tunnels with Two Measured Interfaces written by C. F. Lo and published by . This book was released on 1990 with total page pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Wall Wind Tunnels written by Marie H. Tuttle and published by . This book was released on 1986 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 Adaptive Wall Wind Tunnel Investigation of a Circulation Controlled Circular Cylinder written by Roland Gunther Berndt and published by . This book was released on 199? with total page 266 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Wall Wind Tunnels written by Marie H. Tuttle and published by . This book was released on 1982 with total page 44 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Adaptive Wall Wind Tunnels A Selected Annotated Bibliography written by Marie H. Tuttle and published by . This book was released on 1986 with total page 60 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book Experimental Investigation of the Effect of Wall Adaptation on Flow Over a Cylinder in a Modernized Adaptive wall Wind Tunnel written by Michael Joseph Bishop and published by . This book was released on 2010 with total page 140 pages. Available in PDF, EPUB and Kindle. Book excerpt: A renovation of an adaptive-wall wind tunnel was completed to improve flow quality, automate data acquisition, integrate a three-axis traversing mechanism, and regain functionality of an adaptive-wall test section. Redesign of the settling chamber significantly improved flow quality, with the resulting turbulence intensity of 0.3% and flow uniformity of ±0.6% matching characteristics of research-grade wind tunnels. The functionality of the adaptive-wall test section was tested by analyzing the effect of wall adaptation on flow development over a circular cylinder. Experiments were carried out for a Reynolds number (Red) of 57,000 for three blockage ratios: 5%, 8%, and 17%. Measurements were made in three wall configurations: geometrically straight walls (GSW), aerodynamically straight walls (ASW), and streamlined walls (SLW). Solid blockage effects were clearly evident in cylinder surface pressure distributions for the GSW and ASW configurations, manifested by an increased peak suction and base suction. Upon streamlining the walls, pressure distributions for each blockage ratio matched distributions expected for low blockage ratios. Wake blockage limited wake growth in the GSW configuration at 7.75 and 15 diameters downstream of the cylinder for blockages of 17% and 8%, respectively. This adverse effect was rectified by streamlining the walls with the resulting wake width development matching that expected for low blockage ratios. Wake vortex shedding frequency and shear layer instability frequency increased in the GSW and ASW configurations with increasing blockage ratio. Invariance of the near wake width with wall configuration suggests that frequency increase is caused by the increased velocity due to solid blockage effects. For all the blockage ratios investigated, the increased wake vortex shedding frequency observed in the ASW and GSW configurations was corrected in the SLW configuration, with the resulting Strouhal numbers of about 0.19, matching that expected for low blockage ratios at the investigated Red.
Download or read book Experimental Investigation of a 2D circulation Controlled Cylinder in an Adaptive Wall Wind Tunnel written by Fabrizio Adalberto Maria Dionisio and published by . This book was released on 2003 with total page 320 pages. Available in PDF, EPUB and Kindle. Book excerpt:
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 63 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 Adaptive Wall Technology for Minimization of Wall Interferences in Transonic Wind Tunnels written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-06-30 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Modern experimental techniques to improve free air simulations in transonic wind tunnels by use of adaptive wall technology are reviewed. Considered are the significant advantages of adaptive wall testing techniques with respect to wall interferences, Reynolds number, tunnel drive power, and flow quality. The application of these testing techniques relies on making the test section boundaries adjustable and using a rapid wall adjustment procedure. A historical overview shows how the disjointed development of these testing techniques, since 1938, is closely linked to available computer support. An overview of Adaptive Wall Test Section (AWTS) designs shows a preference for use of relatively simple designs with solid adaptive walls in 2- and 3-D testing. Operational aspects of AWTS's are discussed with regard to production type operation where adaptive wall adjustments need to be quick. Both 2- and 3-D data are presented to illustrate the quality of AWTS data over the transonic speed range. Adaptive wall technology is available for general use in 2-D testing, even in cryogenic wind tunnels. In 3-D testing, more refinement of the adaptive wall testing techniques is required before more widespread use can be planned. Wolf, Stephen W. D. Unspecified Center NAS1-17919; RTOP 505-61-01-02...
Download or read book Fluid Dynamics Panel Working Group 12 on Adaptive Wind Tunnel Walls Technology and Applications Les Souffleries a Paroi Adaptable Technologies Et Applications written by and published by . This book was released on 1990 with total page 155 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents the results of a study on adaptive-wall wind tunnels. This presentation reviews the history and state of the art of adaptive-wall technology, with regard to both the various streamlining algorithms and the existing adaptive-wall facilities; discusses limitations and open questions of adaptive-wall methods and compares them with passive-wall correction techniques; assesses residual wall interferences; presents the prospects for high-productivity and unsteady flow testing with adaptive walls; and makes recommendations for future developments. Keywords: Wind tunnels walls; Adaptive systems; Unsteady flow; Algorithms; Streamlining; Aerodynamic characteristics. (edc).
Download or read book Experiments in a Three Dimensional Adaptive Wall Wind Tunnel written by National Aeronautics and Space Administration (NASA) and published by Createspace Independent Publishing Platform. This book was released on 2018-08-20 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: Three dimensional adaptive-wall experiments were performed in the Ames Research Center (ARC) 25- by 13-cm indraft wind tunnel. A semispan wing model was mounted to one sidewall of a test section with solid sidewalls, and slotted top and bottom walls. The test section had separate top and bottom plenums which were divided into streamwise and cross-stream compartments. An iterative procedure was demonstrated for measuring wall interference and for adjusting the plenum compartment pressures to eliminate such interference. The experiments were conducted at a freestream Mach number of 0.60 and model angles of attack between 0 and 6 deg. Although in all the experiments wall interference was reduced after the plenum pressures were adjusted, interference could not be completely eliminated. Schairer, E. T. Ames Research Center NASA-TP-2210, A-9255, NAS 1.60:2210 RTOP 505-31-51...
Download or read book Les Souffleries Paroi Adaptable written by and published by . This book was released on 1990 with total page 145 pages. Available in PDF, EPUB and Kindle. Book excerpt: This report presents the results of a study by Working Group 12 of the Fluid Dynamics Panel of AGARD on adaptive-wall wind tunnels. This presentation reviews the history and state of the art of adaptive-wall technology with regard to both the various streamlining algorithms and the existing adaptive-wall facilities; discusses limitations and open questions of adaptive-wall methods and compares them with passive-wall correction techniques: assesses residual wall interferences; presents the prospects for high-productivity and unsteady flow testing with adaptive walls; and males recommendations for future developments. The participants in WG12 represented Canada, France, Federal Republic of Germany, Italy, Netherlands, Turkey, United Kingdom, and United States.
Download or read book Experiments in a Three dimensional Adaptive wall Wind Tunnel written by Edward T. Schairer and published by . This book was released on 1983 with total page 40 pages. Available in PDF, EPUB and Kindle. Book excerpt:
Download or read book An Experimental Study of an Adaptive Wall Wind Tunnel 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 156 pages. Available in PDF, EPUB and Kindle. Book excerpt: 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...
