National Advisory Committee for Aeronautics (NACA) - 41 Matching Results

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Preliminary Investigation of a Ceramic Lining for a Combustion Chamber for Gas-Turbine Use

Description: Combustion chamber liners for gas turbines and experimental set-ups were tested for failure. A ceramic-lined test chamber was operated at fuel/air ratios up to 0.050. Thermal-shock evaluation indicated that a ceramic lining, which expands after firing, would crack but would not fall apart during operation. Refractoriness of the lining and the resistance to mechanical shock were adequate. In general, shell temperature reductions of approximately 400 deg F were effected by the use of this lining at fuel/air ratios of 0.016 and 0.050. The mechanism of failure of the ceramic lining was induced by sudden heating and cooling during operation.
Date: April 12, 1948
Creator: Woodward, William H & Bobrowsky, A R
Partner: UNT Libraries Government Documents Department

Analytical investigation of distribution of centrifugal stresses and their relation to limiting operating temperatures in gas-turbine blades

Description: From Introduction: "Analyses that provide a basis for comparing the centrifugal-stress distributions inherent in jet-engine turbine blades of several designs currently in use were therefore made and are presented."
Date: April 12, 1948
Creator: Kemp, Richard H & Morgan, William C
Partner: UNT Libraries Government Documents Department

Flight investigation to determine the hinge moments of a beveled-edge aileron on a 45 degree sweptback wing at transonic and low supersonic speeds

Description: Report discussing testing of a model of the pilotless aircraft RM-1 to measure aileron hinge moments in flight in order to determine the reason for loss of roll stabilization at supercritical speeds in flight. The aileron was found to become quickly underbalanced over the full deflection range at supercritical speeds. Information about the general flight behavior, aileron hinge moments, and roll stabilization of the model is provided.
Date: November 12, 1947
Creator: Gardner, William N. & Curfman, Howard J., Jr.
Partner: UNT Libraries Government Documents Department

Helicopter stability

Description: Report presenting information about some of the fundamental concepts and lines of development that may be undertaken regarding helicopter stability. Some of the principles discussed include method of control, control lag, stability characteristics, control forces, and center of gravity. Some of the means for improvement discussed include use of a horizontal stabilizer, use of trim devices, use of power-operated controls, automatic controls, and choice and grouping of indicating instruments.
Date: April 12, 1948
Creator: Gustafson, F. B. & Reeder, J. P.
Partner: UNT Libraries Government Documents Department

High-speed wind-tunnel tests of a 1/16-scale model of the D-558 research airplane basic longitudinal stability of the D-558-1

Description: Report presenting the results of testing on a model of the D-558-1 in order to determine its pitching-moment, lift, and drag characteristics with no nose-inlet flow, and with the tail removed and at a constant setting. Only a limited analysis is provided.
Date: May 12, 1948
Creator: Wright, John B.
Partner: UNT Libraries Government Documents Department

Preliminary theoretical and flight investigation of the lateral oscillation of the X-1 airplane

Description: Report presenting the results of flight tests showing lateral oscillation in the Bell X-1 and calculations created to determine the effects of changes in several mass and aerodynamic parameters on the lateral oscillations. Calculations indicate that lateral stability should be improved by a more positive inclination of the principal axis of inertia or a reduction of the value of yawing moment of inertia.
Date: August 12, 1949
Creator: Drake, Hubert M. & Wall, Helen L.
Partner: UNT Libraries Government Documents Department

Full-scale investigation of the maximum lift and flow characteristics of an airplane having approximately triangular plan form

Description: Report discussing an investigation of the DM-1 glider, which has an approximately triangular plan form, with auxiliary studies of a model of triangular wings. The pitching-moment coefficient, drag coefficient, and angle of attack with the lift coefficient are provided. Results indicated that the angles of descent without power are likely to be prohibitive and airplanes with the tested type of wings will not be able to land safely without power.
Date: February 12, 1947
Creator: Wilson, Herbert A., Jr. & Lovell, J. Calvin
Partner: UNT Libraries Government Documents Department

Hydrodynamic characteristics of a swept planing-tail hull

Description: Report presenting the hydrodynamic characteristics of a swept planing-tail hull as determined by water tank testing. The hull shape was based on results from previous testing indicating that symmetrical airfoil sections and slender boom-like afterbodies lower the drag. Results regarding spray characteristics, take-off stability and trims, landing stability, resistance, and directional stability are presented.
Date: September 12, 1949
Creator: Mckann, Robert E.; Coffee, Claude W. & Arabian, Donald D.
Partner: UNT Libraries Government Documents Department

Investigation of Rim Cracking in Turbine Wheels with Welded Blades

Description: Rim cracking in turbine wheels with welded blades was evaluated. The problem is explained on the basis of the occurrence of plastic flow in the rim during transient starting conditions when thermal compressive stresses resulting from high-temperature gradients exceed the proportional elastic limit of the material.
Date: February 12, 1947
Creator: Millenson, M. B. & Manson, S. S.
Partner: UNT Libraries Government Documents Department

Knock-Limited Performance of Triptane and Xylidines Blended with 28-R Aviation Fuel at High Compression Ratios and Maximum-Economy Spark Setting

Description: An investigation was conducted to evaluate the possibilities of utilizing the high-performance characteristics of triptane and xylidines blended with 28-R fuel in order to increase fuel economy by the use of high compression ratios and maximum-economy spark setting. Full-scale single-cylinder knock tests were run with 20 deg B.T.C. and maximum-economy spark settings at compression ratios of 6.9, 8.0, and 10.0, and with two inlet-air temperatures. The fuels tested consisted of triptane, four triptane and one xylidines blend with 28-R, and 28-R fuel alone. Indicated specific fuel consumption at lean mixtures was decreased approximately 17 percent at a compression ratio of 10.0 and maximum-economy spark setting, as compared to that obtained with a compression ratio of 6.9 and normal spark setting. When compression ratio was increased from 6.9 to 10.0 at an inlet-air temperature of 150 F, normal spark setting, and a fuel-air ratio of 0.065, 55-percent triptane was required with 28-R fuel to maintain the knock-limited brake power level obtained with 28-R fuel at a compression ratio of 6.9. Brake specific fuel consumption was decreased 17.5 percent at a compression ratio of 10.0 relative to that obtained at a compression ratio of 6.9. Approximately similar results were noted at an inlet-air temperature of 250 F. For concentrations up through at least 20 percent, triptane can be more efficiently used at normal than at maximum-economy spark setting to maintain a constant knock-limited power output over the range of compression ratios tested.
Date: December 12, 1946
Creator: Held, Louis F. & Pritchard, Ernest I.
Partner: UNT Libraries Government Documents Department

Calculations of the Dynamic Stress of Several Airplane Wings in Various Gusts

Description: A series of calculations of the dynamic response of airplane wings to gusts were made with the purpose of showing the relative response of a reference airplane, the DC-3 airplane, and of newer types of airplanes represented by the DC-4, DC-6, and L-49 airplanes. Additional calculations were made for the DC-6 airplane to show the effects of speed and altitude. On the basis of the method of calculation used and the conditions selected for analysis, it is indicated that: 1) The newer airplanes show appreciably greater dynamic stress in gusts then does the reference airplane; 2) Increasing the forward speed or the operating altitude results in an increase of the dynamic stress ratio for the gust with a gradient distance of 10 chords.
Date: July 12, 1948
Creator: Pierce, Harold B.
Partner: UNT Libraries Government Documents Department