National Advisory Committee for Aeronautics (NACA) - 331 Matching Results

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An investigation of aircraft heaters IX: measured and predicted performance of two exhaust gas-air heat exchangers and an apparatus for evaluating exhaust gas-air heat exchangers

Description: Report presenting laboratory testing to determine the thermal output and pressure drop characteristics of the Airesearch and Solar fluted-type exhaust gas-air heat exchangers. The apparatus used in these tests consisted of a natural gas furnace of 3,000,000 Btu per hour thermal capacity, a centrifugal blower, and a system of ducting and various measuring devices. Results regarding the method of analysis, the Airesearch heat exchanger tests, the solar heat exchanger tests, and a comparison of the two heat exchangers are provided.
Date: March 1943
Creator: Boelter, L. M. K.; Miller, M. A.; Sharp, W. H.; Morrin, E. H.; Iversen, H. W. & Mason, W. E.
Partner: UNT Libraries Government Documents Department

The Measurement of Fuel-Air Ratio by Analysis for the Oxidized Exhaust Gas

Description: An investigation was made to determine a method of measuring fuel-air ratio that could be used for test purposes in flight and for checking conventional equipment in the laboratory. Two single-cylinder test engines equipped with typical commercial engine cylinders were used. The fuel-air ratio of the mixture delivered to the engines was determined by direct measurement of the quantity of air and of fuel supplied and also by analysis of the oxidized exhaust gas and of the normal exhaust gas. Five fuels were used: gasoline that complied with Army-Navy fuel Specification No. AN-VV-F-781 and four mixtures of this gasoline with toluene, benzene, and xylene. The method of determining the fuel-air ratio described in this report involves the measurement of the carbon-dioxide content of the oxidized exhaust gas and the use of graphs for the presented equation. This method is considered useful in aircraft, in the field, or in the laboratory for a range of fuel-air ratios from 0.047 to 0.124.
Date: January 1, 1943
Creator: Gerrish, Harold C. & Meem, J. Lawrence, Jr.
Partner: UNT Libraries Government Documents Department

The effect of compressibility on two-dimensional tunnel-wall interference for a symmetrical airfoil

Description: Summary: The effective change in the velocity of flow past a wing section, caused by the presence of wind-tunnel walls, is known for potential flow. This theory is extended by investigation of the two-dimensional compressible flow past a thin Rankine Oval. It is shown that for a symmetrical section at zero angle of attack the velocity increment due to the tunnel walls in the incompressible case must be multiplied by the factor 1/1-M^2 to take account of compressibility effects. The Mach number, M, corresponds to conditions in the wind-tunnel test section with the model removed (p. 1.).
Date: January 1, 1943
Creator: Nitzberg, Gerald E
Partner: UNT Libraries Government Documents Department

The problem of longitudinal stability and control at high speeds

Description: Report discussing the difficulty in pulling of high-speed dives, which is primarily due to the effect of compressibility on the lift of the wing. Some of the means described for providing increased longitudinal control include auxiliary flaps and a controllable stabilizer.
Date: November 1943
Creator: Hood, Manley J. & Allen, H. Julian
Partner: UNT Libraries Government Documents Department

A method of estimating the knock rating of hydrocarbon fuel blend

Description: The usefulness of the knock ratings of pure hydrocarbon compounds would be increased if some reliable method of calculating the knock ratings of fuel blends was known. The purpose of this study was to investigate the possibility of developing a method of predicting the knock ratings of fuel blends.
Date: January 1, 1943
Creator: Sanders, Newell D
Partner: UNT Libraries Government Documents Department

Emergency measures for increasing the range of fighter airplanes

Description: From Summary: "An analysis was made to show the relative effectiveness of streamline external fuel tanks, a fuel tank in the form of a wing mounted in a biplane position, and auxiliary wing panels attached at the wing tips to increase the span as temporary means for increasing the range of a fighter-type airplane. Figures and charts for the various devices considered show the results of calculations of range, duration of flight, and take-off distance for both land-base and carrier operation. The results indicated that the wing-tip extensions were the most promising of the devices considered."
Date: May 1943
Creator: Jones, Robert T. & Wetmore, Joseph W.
Partner: UNT Libraries Government Documents Department

Analysis of wind-tunnel stability and control tests in terms of flying qualities in full-scale airplanes

Description: From Summary: "The analysis of results of wind-tunnel stability and control tests of powered airplane models in terms of the flying qualities of full-scale airplanes is advocated. In order to indicate the topics upon which comments are considered desirable in the report of a wind-tunnel stability and control investigation and to demonstrate the nature of the suggested analysis, the present NACA flying-qualities requirements are discussed in relation to wind-tunnel tests. General procedures for the estimation of flying qualities from wind-tunnel tests are outlined."
Date: October 1943
Creator: Kayten, Gerald G.
Partner: UNT Libraries Government Documents Department

Laminar-boundary-layer oscillations and transition on a flat plate

Description: Report presenting an investigation of oscillations in the laminar boundary layer on a flat plate and their relation to transition to turbulent flow. The characteristics of boundary-layer oscillations were studied most successfully when the oscillations were artificially produced by a vibrating ribbon placed in the boundary layer near the surface. A review of theory regarding laminar-boundary-layer oscillations is provided.
Date: April 1943
Creator: Schubauer, G. B. & Skramstad, H. K.
Partner: UNT Libraries Government Documents Department

Investigation of flow in an axially symmetrical heated jet of air

Description: The work done under this contract falls essentially into two parts: the first part was the design and construction of the equipment and the running of preliminary tests on the 3-inch jet, carried out by Mr. Carl Thiele in 1940; the second part consisting in the measurement in the 1-inch jet flow in an axially symmetrical heated jet of air. (author).
Date: December 1, 1943
Creator: Corrsin, Stanley
Partner: UNT Libraries Government Documents Department

Principles of moment distribution applied to stability of structures composed of bars or plates

Description: Principles of the cross method of moment distribution, which have previously been applied to the stability of structures composed of bars under axial load, are applied to the stability of structures composed of long plates under longitudinal load.
Date: January 1, 1943
Creator: Lundquist, Eugene E.; Stowell, Elbridge Z. & Schuette, Evan H.
Partner: UNT Libraries Government Documents Department

Least-work analysis of the problem of shear lag in box beams

Description: The distribution of stress in the cover sheets of thin-wall box beams is analyzed, with regard to the effect of shear deformation in the cover sheets, by the method of least work. Explicit results are obtained for a number of representative cases that show the influence of the following factors on the stress patterns. (1) Variation of stress in spanwise direction as given by elementary beam theory. (2) Value of a parameter called shear-lag aspect ratio which designates the product of span-width ratio of the beam and of the square root of the ratio of effective shear modulus and tensing modulus of the cover sheets. (3) Value of ratio of cover-sheet stiffness to side-web stiffness. (4) Variation of beam height in span direction. (5) Variation of beam width in span direction. (6) Variation of cover-sheet thickness in span direction. General conclusions are drawn from the results obtained. Among them the most important one appears to be the fact that the shear-lag effect depends primarily on the following tow quantities: (1) the value of the shear-lag aspect ratio. (2) the shape of the curve representing the product of the stress of elementary beam theory and of the cover-sheet thickness.
Date: January 1, 1943
Creator: Hildebrand, Francis B & Reissner, Eric
Partner: UNT Libraries Government Documents Department