ALBERT

All Library Books, journals and Electronic Records Telegrafenberg

feed icon rss

Your email was sent successfully. Check your inbox.

An error occurred while sending the email. Please try again.

Proceed reservation?

Export
  • 1
    Publication Date: 2019-06-28
    Description: An investigation has been conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of upper and lower external nozzle flap geometry on the external afterbody/nozzle drag of nonaxisymmetric two-dimensional convergent-divergent exhaust nozzles having parallel external sidewalls installed on a generic twin-engine, fighter-aircraft model. Tests were conducted over a Mach number range from 0.60 to 1.20 and over an angle-of-attack range from -5 to 9 deg. Nozzle pressure ratio was varied from jet off (1.0) to approximately 10.0, depending on Mach number.
    Keywords: AERODYNAMICS
    Type: NASA-TP-2640 , L-16158 , NAS 1.60:2640
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 2
    Publication Date: 2019-06-28
    Description: A static (wind-off) test was conducted in the Static Test Facility of the 16-ft transonic tunnel to determine the performance and turning effectiveness of post-exit yaw vanes installed on two-dimensional convergent-divergent nozzles. One nozzle design that was previously tested was used as a baseline, simulating dry power and afterburning power nozzles at both 0 and 20 degree pitch vectoring conditions. Vanes were installed on these four nozzle configurations to study the effects of vane deflection angle, longitudinal and lateral location, size, and camber. All vanes were hinged at the nozzle sidewall exit, and in addition, some were also hinged at the vane quarter chord (double-hinged). The vane concepts tested generally produced yaw thrust vectoring angles much less than the geometric vane angles, for (up to 8 percent) resultant thrust losses. When the nozzles were pitch vectored, yawing effectiveness decreased as the vanes were moved downstream. Thrust penalties and yawing effectiveness both decreased rapidly as the vanes were moved outboard (laterally). Vane length and height changes increased yawing effectiveness and thrust ratio losses, while using vane camber, and double-hinged vanes increased resultant yaw angles by 50 to 100 percent.
    Keywords: AERODYNAMICS
    Type: NASA-TP-3085 , L-16784 , NAS 1.60:3085
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 3
    Publication Date: 2019-06-28
    Description: The Langley 16 x 24 inch Water Tunnel is described in detail, along with all the supporting equipment used in its operation as a flow visualization test facility. These include the laser and incandescent lighting systems; and the photographic, video, and laser fluorescence anemometer systems used to make permanent records of the test results. This facility is a closed return water tunnel capable of test section velocities from 0 to 0.75 feet per second with flow through the 16 x 24 inch test section in a downward (vertical) direction. The velocity normally used for testing is 0.25 feet per second where the most uniform flow occurs, and is slow enough to easily observe flow phenomena such as vortex flow with the unaided eye. An overview is given of the operational characteristics, procedures, and capabilities of the water tunnel to potential users of the facility so that they may determine if the facility meets their needs for a planned study.
    Keywords: RESEARCH AND SUPPORT FACILITIES (AIR)
    Type: NASA-TM-104200 , NAS 1.15:104200
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 4
    Publication Date: 2019-06-28
    Description: The origin of dynamic pressure loads on external divergent engine nozzle flaps of the B-1B aircraft was investigated in the NASA/LaRC 16 foot transonic tunnel using a 6 percent full span model with powered engine nacelles. External flap dynamic loads and afterbody drag associated with flap removal were measured using this model. Both dry and max. A/B power nozzles were evaluated in this study. As a result of this study, the principal mechanisms responsible for high dynamic external flap loads were determined along with performance penalty associated with flap removal.
    Keywords: AIRCRAFT PROPULSION AND POWER
    Type: ASME PAPER 91-GT-236
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 5
    Publication Date: 2019-06-28
    Description: An investigation was conducted in the Langley 16-Foot Transonic Tunnel to determine the effects of a turboprop-nacelle installation on the pressure distributions over a swept, supercritical wing. The tests were conducted at Mach numbers from 0.20 to 0.80, at angles of attack from 0 to 5 degrees, nacelle nozzle pressure ratios from 1.0 to 1.6, and at propeller tip speeds from 700 to 800 ft/sec. The results of this study indicate that the turboprop nacelle interference, with and without power, on a swept wing is greater on the inboard wing panel than on the outboard wing panel. The over-the-wing nacelle installation with the propeller upwash on the inboard panel had flow separation problems at a Mach number of 0.80. No severe flow separation problems appear to exist for either propeller rotation direction for the under-the-wing nacelle installation. The local flow disturbances caused by the under-the-wing nacelle installation were in general less severe than for the over-the-wing nacelle installation.
    Keywords: AERODYNAMICS
    Type: NASA-TP-2729 , L-16043 , NAS 1.60:2729
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 6
    Publication Date: 2019-06-28
    Description: An experimental program was conducted in the Langley 16-Foot Transonic Tunnel to evaluate the performance effects of various types of pylons on a 1/17th-scale, low-wing transport model. The model wing was designed for cruise at a Mach number of 0.77 and a lift coefficient of 0.55. The pylons were tested at two wing semispan locations over a range of toe-in angles. The effects of toe-in angle were found to be minimal, but the variation in geometry had a more pronounced effect on the lift characteristics of the model. A pylon whose maximum thickness occurred at the wing trailing edge, known as a compression pylon, proved to be the best choice in terms of retaining the flow characteristics of the wing without pylons. Practical considerations such as structural viability may necessitate modification of the compression pylon concept in order to take advantage of its apparent benefits.
    Keywords: AERODYNAMICS
    Type: NASA-TP-3333 , L-17149 , NAS 1.60:3333
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 7
    Publication Date: 2019-06-28
    Description: A twin-engine, low-wing transport model, with a supercritical wing designed for a cruise Mach number of 0.77 and a lift coefficient of 0.55 was tested in the 16-Foot Transonic Tunnel at NASA Langley Research Center. The purpose of this test was to compare the wing/nacelle interference effects of superfans (BPR 18) with the interference effects of advanced turbofans (BPR 6). Flow-through nacelles were used. Forces and moments on the complete model were measured using a strain gage balance, and extensive surface static pressure measurements were made on the model's wing, nacelles, and pylons. Results of the investigation indicate that superfan nacelles can be installed with approximately the same drag penalty as conventional turbofan nacelles.
    Keywords: AERODYNAMICS
    Type: ASME PAPER 91-GT-241
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 8
    Publication Date: 2019-06-28
    Description: A twin-engine, low-wing transport model, with a supercritical wing of aspect ratio 10.8 designed for a cruise Mach number of 0.77 and a lift coefficient of 0.55, was tested in the Langley 16-Foot Transonic Tunnel. The purpose of this test was to compare the wing-nacelle interference effects of flow-through nacelles simulating superfan engines (very high bypass ratio (BPR is approx. = 18) turbofan engines) with the wing-nacelle interference effects of current-technology turbofans (BPR is approx. = 6). Forces and moments on the complete model were measured with a strain-gage balance, and extensive external static-pressure measurements (383 orifice locations) were made on the wing, nacelles, and pylons of the model. Data were taken at Mach numbers from 0.50 to 0.80 and at model angles of attack from -4 deg to 8 deg. Test results indicate that flow-through nacelles with a very high bypass ratio can be installed on a low-wing transport model with a lower installation drag penalty than for a conventional turbofan nacelle at a design cruise Mach number of 0.77 and lift coefficient of 0.55.
    Keywords: AERODYNAMICS
    Type: NASA-TP-3168 , L-16960 , NAS 1.60:3168
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 9
    Publication Date: 2019-06-28
    Description: Pylon cross-sectional geometries that are intended to reduce propulsion system installation drag were investigated on a 1/17th-scale low-wing transport model in the NASA Langley 16-Foot Transonic Tunnel. The basic design philosophy for these pylons was to alleviate flow acceleration without introducing severe adverse pressure gradients near the pylon/wing junction. This was achieved by means of a gradually, diverging pylon with maximum thickness occurring at the wing trailing edge. The pylon closure occurs aft of the wing trailing edge. The force, surface pressure and surface flow visualization data obtained support this concept.
    Keywords: AIRCRAFT DESIGN, TESTING AND PERFORMANCE
    Type: AIAA PAPER 92-0153
    Format: text
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
  • 10
    Publication Date: 2019-06-28
    Description: Several Gurney flap configurations were tested in the NASA Langley 16 x 24 inch Water Tunnel. These devices provided an increased region of attached flow on a wing upper surface relative to the wing without the flaps. The recirculation region behind the flap was visualized and shown to be consistent with hypotheses stated in previous research. Although the test Reynolds number for this study was several orders of magnitude below those in previous investigations, the effect of the Gurney flaps is in qualitative agreement with them. This is as would be expected from first order effects for high lift devices.
    Keywords: AERODYNAMICS
    Type: NASA-TM-4071 , L-16467 , NAS 1.15:4071
    Format: application/pdf
    Location Call Number Expected Availability
    BibTip Others were also interested in ...
Close ⊗
This website uses cookies and the analysis tool Matomo. More information can be found here...