Note presenting an experimental study using liquid nitrogen made to verify the existence of a temperature gradient as the factor causing the increase in pressure and to investigate the effect on pressure of altering the temperature gradient. The effect on pressure of different heat-leak rates into the container and different quantities of liquid was also investigated. Results regarding the typical pressure history and temperature gradient, effect of stirring liquid on pressure, effect of heat-leak rate and liquid content on pressure, and effect of vapor mixing on pressure are provided.

Note presenting a determination of the spontaneous explosion limits of nine alkylsilanes as a function of temperature and fuel-air composition at a pressure of 1 atmosphere.

From Introduction: "This report presents a computational procedure which provides for the rapid and accurate calculation of any streamline in a series of special flows. Detailed information is given on the boundary conditions and equations used for computing the characteristic nets and stream function."

Report presenting a solution of the Navier-Stokes equation for source and sink flows of a viscous, heat-conducting, compressible fluid for the case of constant total flow energy.

Report presenting that the usual assumption of a uniform vortex cylinder for the wake vortex structure of a uniformly loaded, lifting rotor operating in the hovering or low-speed vertical-ascent flight conditions does not yield useful results for induced velocities in the region about the periphery of the rotor.

From Summary: "The data from previous NACA pressure-distribution investigations of plain flaps and tabs have been analyzed and are presented in this paper in a form readily applicable to the problems of control-surface design. The experimentally determined variation of aerodynamic parameters with flap chord and tab chord are given in chart form and comparisons are made with the theory. With the aid of these charts and the theoretical relationships for a thin airfoil, the aerodynamic characteristics for control surfaces of any plan form with plain flaps and tabs may be determined. A discussion of the basic equations of the thin-airfoil theory and the development of a number of additional equations that will be helpful in tail design are presented in the appendixes. The procedure for applying the data is described and a sample problem of tail design is included."

From Summary: "Trajectories of water droplets moving in the ideal two-dimensional flow field ahead of a body of rectangular cross section and infinite extent in the downstream direction have been calculated by means of a differential analyzer. Data on collection efficiency and distribution of water impingement are presented."

"The carpet-plotting technique is presented in this paper as a more useful and concise method of summarizing cascade data on the NACA 65-series compressor blades given in NACA Technical Note 3916. Carpet plots included permit the selection of the blade camber and the design angle of attack required to fulfill a design vector diagram. Other carpet plots provide means for the prediction of off-design turning angles" (p. 1).

Report presenting an investigation of the aerodynamic characteristics of a wing equipped with a 50-percent-chord sliding flap and a 30-percent-chord slotted flap operating in the slipstreams of two large-diameter propellers in the 300 mph 7- by 10-foot tunnel. Large tunnel-wall effects for which there are no known correction methods were encountered in the tests. Stalling was found to occur in conditions approaching steady level flight at high-power conditions,but a leading-edge slat effectively delayed the stall.

Report presenting an experimental friction study using graphite and mixtures of graphite with lead oxide, cadmium oxide, sodium sulfate, or cadmium sulfate as solid lubricants. Runs were made at temperatures up to 1000 degrees Fahrenheit with various steel and Inconel combinations.

From Summary: "Experimental studies of panel flutter using thin metal plates were conducted at a Mach number of 1.3 to verify its existence and to study the effects of some structural parameters on the flutter characteristics. The effects of tensile forces and buckling were studied on panels clamped front and rear, in addition to initially buckled panels clamped on all four edges. Panel flutter was obtained under controlled laboratory conditions and it was found that tensile forces, shortening the panels, and increasing the bending stiffness were effective means for eliminating flutter. Buckled panels were more susceptible to flutter than unbuckled panels. No apparent systematic trends in the flutter modes or frequencies could be observed."

A two-dimensional low-speed porous-wall cascade tunnel investigation has been conducted to establish the performance of the NACA 65-series compressor blade sections over the useful range of inlet angle, solidity, and section camber. Design points for optimum high-speed operation are presented. The loading limitation is determined for some conditions. Trends of section operating range with increasing section camber are determined for the four inlet angles tested.

Report presenting an investigation to determine the performance and other characteristics of several basic types of thrust reversers. Models of three types, target, tail-pipe cascade, and ring cascade, were tested with cold flow. Results regarding target-type thrust reversers, tail-pipe-cascade thrust reversers, ring-cascade thrust reversers, and thrust modulation are provided.

From Summary: "The results of local-instability tests of H-section plate assemblies and compressive stress-strain tests of extruded 75S-T6 aluminum alloy, obtained to determine flat-plate compressive strengths under stabilized elevated-temperature conditions, are given for temperatures up to 600 degrees Fahrenheit. The results show that methods available for calculating the critical compressive stress at room temperature can also be used at elevated temperatures if the applicable compressive stress-strain curve for the material is given."

"A procedure which takes into account the aerodynamic span effect is given for the determination of the torsional-divergence velocities of monoplanes. The explicit solutions obtained in several cases indicate that the aerodynamic span effect may increase the divergence velocities found by means of the section-force theory by as much as 17 to 40 percent. It is found that the magnitude of the effect increases with increasing degree of stiffness taper and decreases with increasing degree of chord taper" (p. 1).

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."

Report presenting an experimental investigation of the effect of oil viscosity on bearing operation characteristics using a 75-millimeter-bore cylindrical-roller inner-race-riding cage-type bearing. Results regarding DN value, oil flow, viscosity, the combination of DN and oil flow, oil inlet temperature, and improvements to cooling correlation theory are provided.

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.

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

This report seeks to determine what constitutes airplane performance and what line should be followed in seeking to break records if the designer is given a free hand. Some of the considerations for designers include the ratio of engine power to wing area, minor refinements, low wing loading, and duration.

Report presenting the use of the similarity law for steady hypersonic flow about slender shapes as extended to nonsteady flows. The aerodynamic forces and moments are correlated for related shapes by means of this law. The motions of related bodies in free flight could be correlated using the hypersonic similarity parameters and additional parameters relating the inertial properties of the bodies and air densities.

"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).

Report presenting some preliminary calculations for airplanes of current design in order to determine the proper angles of sideslip in order to design ideal vertical tails. Existing simplified calculations for determining these values are not generally applicable to airplanes of current design, but a new solution is proposed. Results for two different airplanes are provided and suggestions for adjusting calculated sideslip values are provided.

Report presenting transient data from approximate step and sinusoidal disturbances of fuel flow on a turbojet engine operated at one constant simulated altitude and flight condition. Results regarding coefficients of differential equations, Fourier representation, frequency response, transient analysis, and a comparison of the various analytical methods are provided.