Download or read book Aerodynamic Characteristics of Perforated Walls for Transonic Wind Tunnels written by J. L. Jacocks and published by . This book was released on 1977 with total page 82 pages. Available in PDF, EPUB and Kindle. Book excerpt: A combined experimental-theoretical approach is developed for determination of the crossflow characteristics of ventilated walls. The technique is based on measurement of static pressures at the boundaries of a two-dimensional flow, calculation of the interior flow properties with Murman- Cole type finite difference techniques, and calculation of the boundary-layer development on and mass flux distribution through the ventilated wall using Patankar-Spalding type solution techniques. Results verify the validity of assuming proportionality between local pressure and flow angle as a boundary condition for wall interference estimates. However, it is also shown that the thickness of the boundary layer represents a dominant influence on the perforated wall characteristics, with both the slope and intercept of the characteristic being dependent on the boundary layer. The effects on the wall characteristics of suppressing the edgetone noise by use of screen overlays or splitter plates within discrete holes are documented.

Download or read book Perforated Wall Noise in the AEDC PWT 16 ft and 4 ft Transonic Tunnels written by O. P. Credle and published by . This book was released on 1971 with total page 78 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report presents the results of recent studies of noise in Propulsion Wind Tunnel (16T) and Aerodynamic Wind Tunnel (4T). Noise levels in the free stream and at the test section wall were measured in both tunnels as a function of Mach number, Reynolds number, wall angle, and wall porosity. In Tunnel 4T, free-stream noise characteristics were also evaluated with solid (taped) test section walls. Test results revealed that the perforated test section wall holes generate discrete frequency, high energy noise. In Tunnel 16T, there is a critical Mach number range in which a wall hole frequency. Test section noise levels were found to vary slightly with wall angle and significantly with Mach number and wall porosity. The wall porosity corresponding to the minimum noise levels was found in Tunnel 4T. (Author).

Download or read book The Effect of Plenum Volume on the Test Section Flow Characteristics of a Perforated Wall Transonic Tunnel written by C. F. Anderson and published by . This book was released on 1970 with total page 72 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tests were conducted in the Aerodynamic Wind Tunnel (1T) of the Propulsion Wind Tunnel Facility to determine the effects of test section plenum chamber volume on the centerline Mach number distributions, wave-cancellation properties of perforated walls, model force data, and tunnel acoustics at Mach numbers from 0.6 to 1.3. Results were obtained with plenum chambers of four different sizes at plenum-to-test section volume ratios between 8.3 and 0.8. Reducing plenum volume produced no measurable effect at Mach numbers below 0.95. At Mach numbers above 0.95, decreasing the plenum volume increased the internal plenum losses, increased the plenum suction requirements, and increased the centerline Mach number deviations; however, the Mach number deviations were small at Mach numbers below 1.15. Reducing the plenum volume also produced a small increase in the effective wall porosity but had no measurable effect on measured model forces except to increase the forebody drag coefficient at Mach numbers above 1.05. Changes in the plenum volume had no significant effect on tunnel acoustics. (Author).

Download or read book Some Aspects of the Behavior of Perforated Transonic Wind Tunnel Walls written by Paul F. Maeder and published by . This book was released on 1954 with total page 106 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Boundary Layer on Perforated Wall Characteristics in Transonic Wind Tunnels written by J. Lukasiewicz and published by . This book was released on 1957 with total page 16 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 1961 with total page 424 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Plenum Volume on the Test Section Flow Characteristics of a Perforated Wall Transonic Tunnel written by and published by . This book was released on 1970 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tests were conducted in the Aerodynamic Wind Tunnel (1T) of the Propulsion Wind Tunnel Facility to determine the effects of test section plenum chamber volume on the centerline Mach number distributions, wave-cancellation properties of perforated walls, model force data, and tunnel acoustics at Mach numbers from 0.6 to 1.3. Results were obtained with plenum chambers of four different sizes at plenum-to-test section volume ratios between 8.3 and 0.8. Reducing plenum volume produced no measurable effect at Mach numbers below 0.95. At Mach numbers above 0.95, decreasing the plenum volume increased the internal plenum losses, increased the plenum suction requirements, and increased the centerline Mach number deviations; however, the Mach number deviations were small at Mach numbers below 1.15. Reducing the plenum volume also produced a small increase in the effective wall porosity but had no measurable effect on measured model forces except to increase the forebody drag coefficient at Mach numbers above 1.05. Changes in the plenum volume had no significant effect on tunnel acoustics. (Author).

Download or read book Scientific and Technical Aerospace Reports written by and published by . This book was released on 1995 with total page 704 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book The Effect of Plenum Volume on the Test Section Flow Characteristics of a Perforated Wall Transonic Tunnel written by and published by . This book was released on 1970 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tests were conducted in the Aerodynamic Wind Tunnel (1T) of the Propulsion Wind Tunnel Facility to determine the effects of test section plenum chamber volume on the centerline Mach number distributions, wave-cancellation properties of perforated walls, model force data, and tunnel acoustics at Mach numbers from 0.6 to 1.3. Results were obtained with plenum chambers of four different sizes at plenum-to-test section volume ratios between 8.3 and 0.8. Reducing plenum volume produced no measurable effect at Mach numbers below 0.95. At Mach numbers above 0.95, decreasing the plenum volume increased the internal plenum losses, increased the plenum suction requirements, and increased the centerline Mach number deviations; however, the Mach number deviations were small at Mach numbers below 1.15. Reducing the plenum volume also produced a small increase in the effective wall porosity but had no measurable effect on measured model forces except to increase the forebody drag coefficient at Mach numbers above 1.05. Changes in the plenum volume had no significant effect on tunnel acoustics. (Author).

Download or read book An Experimental Investigation of the Transonic flow generation and Shock wave reflection Characteristics of a Two dimensional Wind Tunnel with 17 percent open Perforated Walls written by Don D. Davis and published by . This book was released on 1954 with total page 48 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Effects of Window Configuration on Model Pressure Distribution in Wind Tunnels with Perforated Walls written by F. L. Heltsley and published by . This book was released on 1981 with total page 59 pages. Available in PDF, EPUB and Kindle. Book excerpt: Larger optical windows for access to the model flow field in the Arnold Engineering Development Center (AEDC) transonic wind tunnels will be required for optimum utilization of the laser velocimeter (LV). A combined analytical and experimental investigation was performed to assess the effects of such windows upon the performance of the perforated walls. The experimental results from the Aerodynamic Wind Tunnel (1T) indicate that although the wall interference characteristics of some window configurations approach the standard porous wall, none of the configurations tested exhibited adequate wave cancellation for all Mach numbers from M at infinity = 1.0 through 1.4. A variable porosity wall arrangement is described which appears to be capable of providing acceptable optical access without adversely affecting the tunnel flow field. (Author).

Download or read book Flow Generation Properties of Five Transonic Wind Tunnel Test Section Wall Configurations written by R. L. Parker (Jr.) and published by . This book was released on 1975 with total page 52 pages. Available in PDF, EPUB and Kindle. Book excerpt:

Download or read book Suppression of Perforated Wall Noise in a Transonic Wind Tunnel and the Effects on Aerodynamic Data written by J. L. Jacocks and published by . This book was released on 1978 with total page 51 pages. Available in PDF, EPUB and Kindle. Book excerpt: Tests were conducted to determine the effect of screen overlays installed on the airside test section walls for the purpose of suppressing the wall noise. Data are presented to illustrate that the screens and resulting noise reduction affected the test section logitudinal flow uniformity, plenum-stream calibration, wave cancellation properties of the walls, transition Reynolds number, and shock/boundary-layer interaction. In general, the effect of noise reduction on viscous phenomena was similar to that observed with decreased Reynolds number.

Download or read book Perforated Wall Noise in the AEDC PWT 16 ft and 4 ft Transonic Tunnels written by and published by . This book was released on 1971 with total page 0 pages. Available in PDF, EPUB and Kindle. Book excerpt: The report presents the results of recent studies of noise in Propulsion Wind Tunnel (16T) and Aerodynamic Wind Tunnel (4T). Noise levels in the free stream and at the test section wall were measured in both tunnels as a function of Mach number, Reynolds number, wall angle, and wall porosity. In Tunnel 4T, free-stream noise characteristics were also evaluated with solid (taped) test section walls. Test results revealed that the perforated test section wall holes generate discrete frequency, high energy noise. In Tunnel 16T, there is a critical Mach number range in which a wall hole frequency. Test section noise levels were found to vary slightly with wall angle and significantly with Mach number and wall porosity. The wall porosity corresponding to the minimum noise levels was found in Tunnel 4T. (Author).

Download or read book Aerodynamic Characteristics in Pitch of Several Triple body Missile Configurations at Mach Numbers 0 6 to 1 4 written by Earl D. Knechtel and published by . This book was released on 1956 with total page 36 pages. Available in PDF, EPUB and Kindle. Book excerpt: An experimental investigation was conducted to determine the longitudinal aerodynamic characteristics at transonic speeds of missile configurations having three blunted cone-cylinder bodies. Modifications of the basic model were tested to indicate the effects of (a) relative lengths of coplanar bodies, (b) seals between the cylindrical portions of the bodies, (c) horizontal connecting surfaces near the rear of the bodies, and (d) triangular rather than coplanar body grouping. Lift, drag, and pitching-moment data were obtained at angles of attack from -4 to 12 degrees and Mach numbers from 0.6 to 1.4 for a constant Reynolds number of 5,500,000, based on average body length.

Download or read book Applied Mechanics Reviews written by and published by . This book was released on 1948 with total page 770 pages. Available in PDF, EPUB and Kindle. Book excerpt:

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: