An investigation was made comparing the performance of JFC-2 fuel and unleaded, clear gasoline in a 3000-pound-thrust turbojet engine. The JFC-2 fuel was a blend of percent diesel fuel and 25 percent aviation gasoline. Engine combustion efficiency was equal to that obtained with gasoline at rated engine speed and altitudes up to 35,000 feet, but at lower engine speeds or at higher altitudes the JFC-2 fuel gave lower combustion efficiency. No discernible difference was obtained in starting or low-speed combustiion blow-out characteristics of the two fuels. Turbine-discharge radial temperature profiles were nearly the same at altitudes up to 35,000 feet.

From Introduction: "The purpose of this report is to present the results of the investigation, to compare the coolant-flow requirements of the two configurations, and to show what advantages an air-cooled internal-strut-supported blade may have over an equivalent shell-supported air-cooled blade."

From Introduction: "The problem of free-convection flow as produced by a body force about a flat plate in the direction of the body force was studied at the NACA Lewis laboratory and is treated in a formal and more general manner herein. The method used is somewhat similar to that used in reference 4 wherein consideration was given to the free-convection flow at high Grashof numbers in a horizontal cylinder which had a variable surface-temperature distribution. In addition, the numerical solutions of references 2 and 3 are herein extended to cover a more complete range of variables."

Note presenting tests to determine local heat-transfer coefficients and friction factors for fully developed turbulent flow of air in a smooth electrically heated tube with an inside diameter of 0.87 inch and a length of 87 inches. Testing occurred at high ratios of wall to fluid bulk temperatures. Results regarding the predicted temperature and velocity distributions, Nusslet numbers, friction factors, velocity distributions, and temperature distributions are provided.

An analysis of inlet-turbojet-engine matching for a range of Mach numbers up to 2.0 indicates large performance penalties when fixed-geometry inlets are used. Use of variable-geometry inlets, however, nearly eliminates th The analysis was confirmed experimentally by investigating at Mach numbers of 0, 0.63, and 1.5 to 2.0 two single oblique-shock-type inlets of different compression-ramp angles, which simulated a variable-geometry configuration. The experimental investigation indicated that total-pressure recoveries comparable withose attainable with well designed nose inlets were obtained with the side inlets when all the boundary layer ahead of the inlets was removed. Serious drag penalties resulted at a Mach number of 2.0 from the use of blunt-cowl leading edges. However, sharp-lip inlets produced large losses in thrust for the take-off condition. These thrust penalties which are associated with the the low-speed operation of the sharp-lip inlet designs can probably be avoided without impairing the supersonic performance of the inlet by the use of auxiliary inlets or blow-in doors.

From Summary: "Results of an analytical and a sea-level experimental investigation of a turbojet engine with proportional speed control are presented."

From Summary: "Approximate shapes of nonlifting bodies having minimum pressure foredrag at high supersonic airspeeds are calculated.With the aid of Newton's law of resistance, the investigation is carried out for various combinations of the conditions of given body length, base diameter, surface area, and volume. In general it is found that when body length is fixed, the body has a blunt nose; whereas, when the length is not fixed, the body has a sharp nose."

Report presenting the use of molybdenum disulfide as a solid film lubricant in applications where designs or temperatures preclude liquid lubricants is dependent on successful bonding of the powder to the surface to be lubricated. An investigation was conducted to determine the basic mechanism of bonding and to extend application of the bonding to a variety of materials. Results regarding an examination of electron diffraction of MoS2 dusted and rubbed on steel, adherence of dry powders to metals, chemical action in bonding mechanism, other resin-forming liquid vehicles, bonding of MoS2 and other powders to various materials, and analysis of solid film by electron diffraction are provided.

"Graphs and formulas are given with the aid of which all the aerodynamic coefficients required for computing the lateral dynamic stability can be determined. A number of numerical examples are given for obtaining the stability derivatives and solving the characteristic-stability equation. Approximate formulas are derived with the aid of which rapid preliminary computations may be made and the stability coefficients corrected for certain modifications of the airplane" (p. 1).

"A coincidence Geiger counter system was constructed for the absolute measurement of the activity of radioactive substances made in a cyclotron. The average beam current in the cyclotron can be calculated from the number of disintegrations per second observed, the half-life of the radioactive substance, and the reaction cross section" (p. 1).

Report presenting an investigation conducted with a conventional turbojet fuel, MIL-F-5624 (JP-3), and a low-volatility, high-density hydrocarbon, monomethylnaphthalene, in a vaporizing-type combustor to determine the combustion efficiency for variations in inlet-air conditions and fuel flow and to what extent fuel vaporization would minimize differences in combustion efficiency between the two fuels. Results regarding the performance of the combustor, correlation parameter, pressure-drop characteristics, and other miscellaneous observations are provided.

Report presenting supersonic profiles of minimum pressure drag for a given thickness ratio and a given area created by using non-linear pressure relation and compared with minimum-drag profiles found by linearized theory. The parameters determining the airfoil shape for a given thickness ratio found by linear and nonlinear theory are presented in graphs as a function of the base pressure coefficient.

The performance of MIL-F-5624A fuels, grades JP-3 and JP-4, was investigated in an axial-flow turbojet engine over a range of altitude conditions of 10,000 to 55,000 feet. Examination of the fuel flow, combustion efficiency, and net thrust specific fuel consumption showed the grade JP-4 fuel to be slightly inferior to the grade JP-3 fuel, although the altitude ignition limits were essentially equal for the two fuels over a range of flight Mach numbers and fuel-inlet temperatures.

Note presenting a theoretical solution obtained for the problem of the compressive buckling of flat rectangular Metalite type sandwich plates with simply supported loaded edges and clamped unloaded edges. The solution is based on the general small-deflection theory for flat sandwich plates developed in a previous NACA report. Results regarding the stability criterion and buckling curves, correction for plasticity, and a comparison with theoretical results are provided.

"The measurements of part V (reference 1) of this series of reports, which concerned comparatively long ring profiles, are supplemented by measurements on shorter rings as they are used for shrouded propellers and cowlings of ring-shaped radiators. Mass-flow coefficients and profile drags are given. Furthermore, it has to be determined how far the potential theory describes the flow phenomenon with sufficient accuracy and whether the present theory for the calculation of thin annular profile yields useful profile forms and is suitable for determination of the mass flow for thick profiles" (p. 1).

The dependence of the maximum incremental velocities and air forces on a circular cowling on the mass flow and the angle of attack of the oblique flow is determined with the aid of pressure-distribution measurements. The particular cowling tested had been partially investigated in NACA TM 1327.

Memorandum presenting the tail-pipe fuel ratio, mass flow of combustion gas, and radial fuel flow distribution on cooling requirements of tail-pipe burner with annular cooling-air passage.

The effects of tail-pipe fuel-air ratio (exhaust-gas temperatures from approximately 3060 degrees to 3825 degrees R), radial distribution of tail-pipe fuel flow, and mass flow of combustion gas and the inside wall were determined for an experimental tail-pipe burner cooled by air flowing through and insulated cooling-air to combustion gas mass flow from 0.066 to 0.192 were also determined. Results regarding the reproducibility of combustion-gas temperature profiles, effect of variables on average longitudinal profiles of combustion-gas temperature, variation of gas temperatures near the wall with cooling-air flow and temperature, and effects of variables on transverse gas temperatures are provided.

From Summary: "The transonic similarity rules have been applied to the correlation of experimental data for a series of 22 rectangular wings having symmetrical NACA 63A-series sections, aspect ratios from 1/2 to 6, and thicknesses from 2 to 10 percent. The data were obtained by use of the transonic bump technique over a Mach number range from 0.40 to 1.10, corresponding to a Reynolds number range from 1.25 to 2.05 million. The results show that it is possible to correlate experimental data throughout the subsonic, transonic, and moderate supersonic regimes by using the transonic similarity parameters in forms which are consistent with the Prandtl-Glauert rule of linearized theory."

"The corrosion resistance of unprotected magnesium-zinc-zirconium alloy ZK60A was determined in a marine atmosphere and in tidewater. The unprotected alloy was so rapidly attacked in tidewater that it would be of no practical value in applications subject to wetting by sea water. In the marine atmosphere the rate of corrosion was much less and the alloy should give good service if adequately protected" (p. 1).

"Several common methods for curve fitting a set of data by least squares are described and evaluated. The methods are evaluated by applying them to an example taken from aerodynamics: the problem of calculating the stability parameters of an airplane from flight data. There are other points considered: application of the methods to minimization problems other than curve fitting and the question of convergence to a mere stationary point as opposed to convergence to a minimum" (p. 1).

Note presenting a determination of the reciprocal equations relating the lift and moment acting on an airfoil due to harmonic oscillations in compressible flow to the indicial lift and moment functions for a pitching airfoil. Two functions are required to completely describe the lift or moment on the airfoil: one is used for describing the effects due to angular position of the airfoil while the other is used for describing the effects due to pitching velocity.

"Direct-reading design charts are presented for 75S-T6 aluminum-alloy flat compression panels having longitudinal extruded Z-section stiffeners. These charts, which cover a wide range of proportions, make possible the direct determination of the stress and all panel dimensions required to carry a given intensity of loading with a given skin thickness and effective length of panel" (p. 1).

The dynamic characteristics of turbojet engine with variable exhaust nozzle area were investigated over a range of altitudes and flight Mach numbers. These characteristics generalize to standard static level condition. Data resulting from approximate step disturbances in either manipulated variable suggested functional relationships from which functions can be derived. The constants of the transfer functions are listed for five combinations of engine speed and exhaust nozzle area. The minimum data needed to completely define the transfer functions were: experimentally determined dynamic characteristics, such as engine time constant and initial rise ratio, resulting from either manipulated variable; static characteristics determined from steady-state performance curves.