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At least 1,099 records · Page 61

Effects of the air breathing propulsion system on space shuttle orbiter subsonic stability and control characteristics (OA71A)

Experimental aerodynamic investigations were conducted on an 0.0405 scale representation of the -89B (2A) Space Shuttle Orbiter in a 7.75 x 11.00 ft low speed wind tunnel during the time period from July 27, 1973 to August 3, 1973. The primary test objective was to investigate the aerodynamic effects of engine nacelle grouping and location on the orbiter ferry mission configuration. Five nacelles were tested, both individually mounted as well as mounted in a podded configuration, at the baseline position and moved 45.0 in. aft (full scale). Orbiter control effectiveness, both with and without nacelles, was recorded at elevon deflections of 0 deg, 5 deg, 10 deg, -10 deg and -20 deg and aileron deflections, about 0 deg elevon, of 0 deg, 5 deg, 10 deg, and 15 deg. The model was sting mounted on a 2.5 inch diameter internal strain gage balance entering through the base region. The nominal angle of attack range was -4 deg or = alpha or = 30 deg. Yaw polars were recorded over the beta range of -10 deg or = beta or = at fixed angles of attack of 0 deg and 10 deg.

Mennell, R. C.↗

Reynolds number effects on boattail drag of exhaust nozzles from wind tunnel and flight tests

A family of nacelle mounted high angle boattail nozzles was tested to investigate Reynolds number effects on drag. The nozzles were flown on a modified F-106B and mounted on scale models of a F-106 in a wind tunnel. A 19- to 1-range of Reynolds number was covered as a result of the large size differences between models and by flying over a range of altitude. In flight, the nozzles were mounted behind J-85 turbojet engines. Jet boundary simulators and a powered turbojet engine simulator were used on the wind tunnel models. Data were taken at Mach numbers of 0.6 and 0.9. Boattail drag was found to be affected by boattail number. The effect is a complex relationship dependent upon boundary layer thickness and nozzle boattail shape. As Reynolds number was increased from the lowest values obtained with scale models, boattail drag first increased to a maximum at the lowest flight Reynolds number and then decreased.

Wilcox, F. A.↗

A study of KC-135 aircraft antenna patterns

Numerical solutions for the radiation patterns of aircraft antennas are evaluated. Designing and locating antennas in order to achieve the desired performance is discussed. The high frequency solutions presented in this report are based on fuselage antennas mounted on a general-type aircraft but applied specifically to the KC-135 aircraft. The roll and elevation plane patterns are computed for a monopole, axial slot, and circumferential slot mounted both over and forward of the wings. In each case the calculated patterns compare very favorably with the measured patterns. The precision pattern measurements were taken on a 1/25 scale model of the KC-135 aircraft at NASA (Langley, Virginia) with special emphasis on reducing the mount and background effects.

Burnside, W. D.↗

Development of a long wavelength spectrometer for the 24-channel multispectral scanner: Instructions for installation, start-up, and adjustment

The basic information is presented, which is required for start-up and operation of two long-wavelength focal-plane and cooler assemblies, including the amplifiers and temperature control systems. The focal plane systems, referred to as the long wavelength spectrometer (LWS) were developed for direct replacement of Arrays 3 and 4 into the multispectral scanner presently being operated by the NASA Manned Spacecraft Center Facility, and Laboratory Support Branch. The equipment is comprised of two major sub-assemblies: Array 3 with three indium antimonide detector channels and Array 4 with seven mercury doped Germanium detector channels. Each array is mounted on a cryogenic cooler and includes the vacuum housings, mounting hardware (x, y, z translation and rotation stages) and detector signal conditioning, temperature control and monitoring electronics. The two arrays were designed to operate independently and do not share common equipment (viz power supplies, housings, mounts, etc.).

Source record↗

Investigation of space shuttle orbiter subsonic stability and control characteristics in the NAAL low speed wind tunnel (0A62b), volume 1

Experimental aerodynamic investigations were conducted on a sting-mounted 0.0405 scale representation of the 140A/B space shuttle orbiter in a 7.75 ft by 11 ft low speed wind tunnel during the time period from November 14, 1973, to December 6, 1973, with the primary test objectives being to establish basic longitudinal stability characteristics in and out of ground effect, as well as lateral-directional stability characteristics in free air. Two dual podded nacelle configurations were also tested, one with three dual podded nacelles on the lower wing surface, and the other with a single dual nacelle on the lower centerline with dual nacelle pylons mounted above each wing. Stability and control characteristics were investigated at nominal elevon, rudder, aileron, and body flap deflections. Pressure bugs were used to determine pressures on the vertical tail at spanwise stations, and aerodynamic force and moment data were measured in the stability axis system by an internally mounted, six component strain gage balance.

Mennell, R.↗

Stability and control characteristics for the inner mold line configuration of the space shuttle orbiter (OA110)

Experimental aerodynamic investigations were conducted on a sting mounted 0.0405-scale representation of the -140A/B inner mold line (IML) space shuttle orbiter in 7.75 x 11 foot low speed wind tunnel, during the time period from 18 March 1974 to 20 March 1974. The primary test objectives were to establish basic longitudinal and lateral-directional stability and control characteristics for the IML orbiter. Additional configurations investigated were sealed elevon hingeline gaps, sealed rudder split line and hingeline gaps, larger radius leading edge on the vertical tail, and sealed speedbrake base. Aerodynamic force and moment data for the orbiter were measured in the body-axis system by an internally mounted, six-component strain gage balance. The model was sting mounted with the center of rotation located at approximately the wing trailing edge. The nominal angle of attack range was from -4 to +30 degrees. Yaw polars were recorded over a nominal yaw angle range from -14 to +14 degrees at constant angles of attack of 0, + or - 5, 10, 15 and 20 degrees.

Hughes, T.↗

A statistical approach to deriving subsystem specifications

In order to produce cost effective environmental test programs, the test specifications must be realistic and to be useful, they must be available early in the life of a program. This paper describes a method for achieving such specifications for subsystems by utilizing the results of a statistical analysis of data acquired at subsystem mounting locations during system level environmental tests. The paper describes the details of this statistical analysis. The resultant recommended levels are a function of the subsystems' mounting location in the spacecraft. Methods of determining this mounting 'zone' are described. Recommendations are then made as to which of the various problem areas encountered should be pursued further.

Keegan, W. B.↗

Reynolds number effects on boattail drag of exhaust nozzles from wind tunnel and flight tests

A family of nacelle-mounted high-angle boattail nozzles was tested to investigate Reynolds number effects on drag. The nozzles were flown on a modified F-106B and mounted on scale models of an F-106 in a wind tunnel. A 19-to-1 range of Reynolds number was covered as a result of the large size differences between models and by flying over a range of altitude. In flight the nozzles were mounted behind J-85 turbojet engines. Jet boundary simulators and a powered turbojet engine simulator were used on the wind tunnel models. Data were taken at Mach numbers of 0.6 and 0.9. Boattail drag was found to be affected by Reynolds number. The effect is a complex relationship dependent upon boundary layer thickness and nozzle boattail shape. As Reynolds number was increased from the lowest values obtained with scale models, boattail drag first increased to a maximum at the lowest flight Reynolds number and then decreased.

Wilcox, F. A.↗

Effects of air breathing engine plumes on SSV orbiter subsonic wing pressure distribution, volume 2

Data presented were obtained during wind tunnel tests of a 0.0405-scale model of the -89B ferry configuration of the space shuttle vehicle orbiter. These tests were conducted in the Rockwell International low speed wind tunnel (NAAL). The primary test objective was to investigate orbiter wing pressure distributions resulting from nacelle plumes above and below the wing. Three six-engine nacelle configurations were tested. One configuration has a twin-podded nacelle mounted above each wing and the others had one mounted below each wing. Both had a centerline twin-podded nacelle mounted below the wing. Wing pressure distribution was determined by locating static pressure bugs on the upper and lower surfaces of the left wing. Pressure bugs were also located on the upper and lower surfaces of the body flap and on the B12 afterbody fairing when it was installed. Base and balance cavity pressures were recorded and a strain gage instrumented beam in the right wing measured elevon hinge moments and normal forces.

Soard, T.↗

Effects of air breathing engine plumes on SSV orbiter subsonic wing pressure distribution (OA57B), volume 1

Data were obtained during wind tunnel tests of a 0.0405-scale model of the ferry configuration of the space shuttle vehicle orbiter conducted in a low speed wind tunnel during the time period of September 18 to September 23, 1973. The primary test objective was to investigate orbiter wing pressure distributions resulting from nacelle plumes above and below the wing. Three six-engine nacelle configurations were tested. One configuration had a twin-podded nacelle mounted above each wing and the others had one mounted below each wing. Both had a centerline twin-podded nacelle mounted below the wing. Wing pressure distribution was determined by locating static pressure bugs on the upper and lower surfaces of the left wing. Pressure bugs were also located on the upper and lower surfaces of the body flap and on the B12 afterbody fairing when it was installed. Base and balance cavity pressures were recorded and a strain gage instrumented beam in the right wing measured elevon hinge moments and normal forces.

Soard, T.↗

Reynolds number effects on boattail drag of exhaust nozzles from wind tunnel and flight tests

A family of nacelle mounted high angle boattail nozzles was tested to investigate Reynolds number effects on drag. The nozzles were flown on a modified F-106B and mounted on scale models of an F-106 in a wind tunnel. A 19- to 1-range of Reynolds number was covered as a result of the large size differences between models and by flying over a range of altitude. In flight the nozzles were mounted behind J-85 turbojet engines. Jet boundary simulators and a powered turbojet engine simulator were used on the wind tunnel models. Data were taken at Mach numbers of 0.6 and 0.9. Boattail drag was found to be affected by Reynolds number. The effect is a complex relationship dependent upon boundary layer thickness and nozzle boattail shape. As Reynolds number was increased from the lowest values obtained with scale models, boattail drag first increased to a maximum at the lowest flight Reynolds number and then decreased.

Wilcox, F. A.↗

Hole cutter

An adjustable hole cutter is described for use in forming circular openings in workpieces. The hole cutter is characterized by a mount of a substantially planar configuration, positionable into a plane paralleling the working plane of a selected workpiece. It also contains a shaft for imparting rotary motion to the mount about an axis of rotation normally related to the working plane, a plurality of stabilizing struts for resiliently supporting the mount in parallelism with the working plane as rotary motion is imparted thereto, a drill bit for drilling a pilot hole concentric with the axis of rotation, and an elongated cutting tool adjustably seated within a radially extended slot.

Thornton, G. E.↗

A study of KC-135 aircraft antenna patterns

Numerical solutions for the radiation patterns of aircraft antennas provide and excellent means of designing and locating antennas in order to achieve the desired performance. The high frequency solutions presented in this paper are based on fuselage antennas mounted on a general-type aircraft but applied specifically to the KC-135 aircraft. The roll and elevation plane patterns are computed for a monopole, axial slot, and circumferential slot mounted both over and forward of the wings. In each case the calculated patterns compare very favorably with the measured patterns. The precision pattern measurements were taken on a 1/25 scale model of the KC-135 aircraft at NASA (Hampton, Va.) with special emphasis on reducing the mount and background effects.

Burnside, W. D.↗

Improved shelf for electronic modules

Self-alining slide assembly improves air flow. Alinement accuracy is incorporated into assembly at time of fabrication, reducing requirement for mounting-hole location accuracy. Amount of labor needed for installation, necessary machining, hardware, and number of mounting points are reduced from previous support system. Load-bearing capability is built into mounting platform.

Marzek, R. A.↗

Low speed aerodynamic characteristics of a transport model having 42.33 deg swept low wing with supercritical airfoil, double-slotted flaps, and T-tail or low tail

A low-speed investigation was conducted in the Langley V/STOL tunnel over an angle-of-attack range of approximately 4 deg to 24 deg to determine the static longitudinal stability characteristics and high lift performance of a general research model which represented an advanced subsonic transport configuration. The model had a 42.33 deg swept, aspect ratio 7.05 wing with a supercritical airfoil and high lift system consisting of a leading edge device (slat or Kruger flap) and a double-slotted flap. The flaps were deflected for take off and landing configurations and were not deflected for tests of the clean configuration. The model was tested with the horizontal tail in either a T tail or low tail position. The effects of various arrangements of flowthrough nacelles which represent a three engine configuration (two large wing-mounted nacelles and a vertical tail mounted nacelle) and a four engine configuration (four smaller wing-mounted nacelles) were determined.

Fournier, P. G.↗

Solid state electro-optic color filter and iris

The electro-optic properties of lanthanum-modified lead zirconate titanate (PLZT) ferroelectric ceramic material are evaluated when utilized as a variable density and/or spectral filter in conjunction with a television scanning system. Emphasis was placed on the development of techniques and procedures for processing the PLZT disks and for applying efficient electrode structures. A number of samples were processed using different combinations of cleaning, electrode material, and deposition process. Best overall performance resulted from the direct evaporation of gold over chrome electrodes. A ruggedized mounting holder assembly was designed, fabricated, and tested. The assembly provides electrical contacts, high voltage protection, and support for the fragile PLZT disk, and permits mounting and optical alignment of the associated polarizers. Operational measurements of a PLZT sample mounted in the holder assembly were performed in conjunction with a television camera and the associated drive circuits. The data verified achievement of the elimination of the observed white-line effect.

Source record↗

A Statistical Approach to Establishing Subsystem Environmental Test Specifications

Results are presented of a research task to evaluate structural responses at various subsystem mounting locations during spacecraft level test exposures to the environments of mechanical shock, acoustic noise, and random vibration. This statistical evaluation is presented in the form of recommended subsystem test specifications for these three environments as normalized to a reference set of spacecraft test levels and are thus suitable for extrapolation to a set of different spacecraft test levels. The recommendations are dependent upon a subsystem's mounting location in a spacecraft, and information is presented on how to determine this mounting zone for a given subsystem.

Keegan, W. B.↗

Effect of Krueger nose flaps on the experimental force and moment characteristics of an oblique wing

Experimental force and moment data are presented for an oblique wing mounted on a body of revolution and equipped with Krueger type nose flaps. The effectiveness of these flaps in making the moment curves more linear by controlling the flow separation on the downstream wing panel at high lift coefficients was determined. The investigation of the effects of the Krueger flaps covered two cases: (1) use of the flaps on the downstream wing panel only and (2) use of the flaps on both wing panels. For part of the tests, the Krueger flaps were mounted on nose flaps that were drooped either 5 deg or 10 deg. The wing was elliptical in planform, had an aspect ratio of 6.0 (based on the unswept span) and was tested at sweep angles of 0, 45 deg, and 50 deg. The Mach-number range covered was from 0.25 to 0.95. It was found that the most effective arrangement of the Krueger flaps for making the pitching-, rolling-, and yawing-moment curves more linear at high lift coefficients was having the Krueger flaps mounted on the nose flaps drooped 5 deg and only on the downstream wing panel.

Hopkins, E. J.↗