National Advisory Committee for Aeronautics (NACA) - 12 Matching Results

Search Results

Two-dimensional aerodynamic characteristics of 34 miscellaneous airfoil sections

Description: The aerodynamic characteristics of 34 miscellaneous airfoils tested in the Langley two-dimensional low-turbulence tunnels are presented. The data include lift, drag, and in some cases, pitching-moment characteristics, for Reynolds numbers between 3.0 x 10 (exp 6) and 9.0 x 10 (exp 6).
Date: January 31, 1949
Creator: Loftin, Laurence K , Jr & Smith, Hamilton A
Partner: UNT Libraries Government Documents Department

Supersonic-tunnel tests of two supersonic airplane model configurations

Description: Report presenting supersonic-tunnel tests of two models of similar supersonic airplane configurations at Mach numbers of 1.55, 1.90, and 2.32 to determine values of the drag, lift, pitching moment, yawing moment, and side force. The models were similar except for the vertical wing location relative to the body axis and horizontal tail; one had a high wing and one had a low wing. Results regarding the precision of data, Reynolds numbers of tests, results at the different Mach numbers, and Schileren photographs are provided.
Date: December 31, 1947
Creator: Ellis, Macon C., Jr.; Hasel, Lowell E. & Grigsby, Carl E.
Partner: UNT Libraries Government Documents Department

Flight investigation at high-subsonic, transonic, and supersonic speeds to determine zero-lift drag of bodies of revolution having fineness ratio of 6.04 and varying positions of maximum diameter

Description: Report presenting a flight investigation of rocket-powered models at high-subsonic, transonic, and supersonic speeds to determine the zero-lift drag of fin-stabilized bodies of revolution differing in maximum diameter. All bodies had 6.04 fineness ratio and cut-off sterns with equal base area. The most favorable location out of the 20-percent, 40-percent, and 60-percent positions were evaluated for different speeds.
Date: August 31, 1949
Creator: Katz, Ellis R.
Partner: UNT Libraries Government Documents Department

Experimental investigation of the effects of sweepback on the flutter of a uniform cantilever wing with a variably located concentrated mass

Description: Report presenting data from 95 subsonic flutter tests conducted in the flutter research tunnel on untapered cantilever wings with sweepback angles of 0, 45, and 60 degrees and carrying a single concentrated weight. The primary purpose of the investigation was to present experimental information to be used to evaluate analytical procedures for determining the flutter speed of weighted sweptback wings. The dynamic pressure, flutter velocity, Mach number, natural and flutter frequencies, and phase-angle relationships of the stresses for the natural and flutter frequencies are presented.
Date: August 31, 1949
Creator: Nelson, Herbert C.. & Tomassoni, John E.
Partner: UNT Libraries Government Documents Department

Development of Outboard Nacelle for the XB-36 Airplane

Description: An investigation of two 1/14 scale model configurations of an outboard nacelle for the XB-36 airplane was made in the Langley two-dimensional low-turbulence tunnels over a range of airplane lift coefficients (C (sub L) = 0.409 to C(sub L) = 0.943) for three representative flow conditions. The purpose of the investigation was to develop a low-drag wing-nacelle pusher combination which incorporated an internal air-flow system. The present investigation has led to the development of a nacelle which had external drag coefficients of similar order of magnitude to those obtained previously from tests of an inboard nacelle configuration at the corresponding operating lift coefficients and from approximately one-third to one-half of those of conventional tractor designs having the same ratio of wing thickness to nacelle diameter.
Date: October 31, 1947
Creator: Nuber, Robert J.
Partner: UNT Libraries Government Documents Department

Preliminary Results of an Altitude-Wind-Tunnel Investigation of a TG-100A Gas Turbine-Propeller Engine, V, Combustion-Chamber Characteristics

Description: An investigation to determine the performance and operational characteristics of the TG-1OOA gas turbine-propeller engine was conducted in the Cleveland altitude wind tunnel. As part of this investigation, the combustion-chamber performance was determined at pressure altitudes from 5000 to 35,000 feet, compressor-inlet rm-pressure ratios of 1.00 and 1.09, and engine speeds from 8000 to 13,000 rpm. Combustion-chamber performance is presented as a function of corrected engine speed and.correcte& horsepower. For the range of corrected engine speeds investigated, over-all total-pressure-loss ratio, cycle efficiency, ana the frac%ional loss in cycle efficiency resulting from pressure losses in the combustion chambers were unaffected by a change in altitude or compressor-inlet ram-pressure ratio. The scatter of combustion- efficiency data tended to obscure any effect of altitude or ram-pressure ratio. For the range of corrected horse-powers investigated, the total-pressure-loss ratio an& the fractional loss in cycle efficiency resulting from pressure losses in the combustion chambers decreased with an increase in corrected horsepower at a constant corrected engine speed. The combustion efficiency remained constant for the range of corrected horse-powers investigated at all corrected engine speeds.
Date: December 31, 1947
Creator: Gensenheyner, Robert M. & Berdysz, Joseph J.
Partner: UNT Libraries Government Documents Department

High Speed Stability and Control Characteristics of a 0.17-Scale Model of the McDonnell XF2H-1 Airplane (TED No. NACA DE 318)

Description: High-speed wind-tunnel tests were conducted of two versions of a 0.17-scale model of the McDonnell XF2H-1 airplane to ascertain the high-speed stability and control characteristics and to study means for raising the high-speed buffet limit of the airplane, The results for the revised model, employing a thinner wing and tail than the original model, revealed a mild diving tendency from 0.75 to 0.80 Mach number, followed by a marked climbing tendency from 0.80 to 0.875 Mach number. The high-speed climbing tendency was caused principally by the pitching-moment characteristics of the wing. At 0.875 Mach number the results for the revised model indicated stick-fixed directional instability over a limited range of yaw angles, apparently caused by separated flow over the vertical tail. The test results indicate that the high-speed buffet limit of the airplane can probably be raised by reducing the thickness and changing the relative location of the horizontal and vertical tails, and by revising the inner portion of the wing to have a lower thickness-to-chord ratio and reduced trailing-edge angle. The addition of the wing-tip tanks to the revised model resulted in a forward shift in the neutral point below 0.82 Mach number.
Date: March 31, 1949
Creator: Axelson, John A. & Emerson, Horace F.
Partner: UNT Libraries Government Documents Department

Analysis of jet-propulsion-engine combustion-chamber pressure losses

Description: From Summary: "The development and the use of a chart for estimating the pressure losses in jet-engine combustion chambers are described. By means of the chart, the pressure losses due to fluid friction and to momentum changes in the air flow accompanying combustion can be separately evaluated. The over-all pressure losses computed from the pressure-loss chart are within 7 percent of the experimental values for the three types of combustion chambers considered herein."
Date: July 31, 1946
Creator: Pinkel, I Irving & Shames, Harold
Partner: UNT Libraries Government Documents Department

Vibration survey of blades in 10-stage axial-flow compressor: 1: static investigation

Description: From Summary: "An investigation was conducted to determine the cause of failures in the seventh- and tenth-stage blades of an axial-flow compressor. The natural frequencies of all rotor blades were measured and critical-speed diagrams were plotted. These data show that the failures were possibly caused by resonance of a first bending-mode vibration excited by a fourth order of the rotor speed in the seventh stage and a sixth order in the tenth stage."
Date: January 31, 1949
Creator: Meyer, André J., Jr. & Calvert, Howard F.
Partner: UNT Libraries Government Documents Department

Summary of results of tumbling investigations made in the Langley 20-foot free-spinning tunnel on 14 dynamic models

Description: Report presenting the tumbling characteristics of dynamic models of 14 airplane designs in the free-spinning tunnel for various loadings and configurations. Conventional airplanes were not found to tumble, but tailless and tail-first airplanes might depending on the amount of static longitudinal stability. Results regarding the effect of dimensional and mass characteristics, effect of controls, use of parachutes as a tumble-recovery device, accelerations, and possibility of pilot escape are provided.
Date: December 31, 1948
Creator: Stone, Ralph W., Jr. & Bryant, Robert L.
Partner: UNT Libraries Government Documents Department