Report presenting a flight investigation to determine the comparative performance of AN-F-58 and AN-F-32 fuels in a 4000-pound-thrust turbojet engine. The fuels were equivalent over the range of conditions investigated. Results regarding corrected net thrust, corrected jet-fuel consumption, variation of corrected tail-pipe temperature, combustor blow-out speeds, and visual observations of the jet exhaust are provided.

Report presenting pressure distributions of three triangular wing models: a wing-alone model, the same wing combined with a body, and a mock-up of a triangular-wing airplane. Results regarding the separation-vortex air flow over triangular wings, general comments regarding the applicability of the study, chordwise pressure distribution, section lift characteristics, center of pressure, and span load distribution are provided.

The following report investigates the isolation of the cause of the unusual tool-wear rates found in machining beryllium as attributed to an inherent characteristic of beryllium, or an effect of inclusions in beryllium, as well as the evaluation of the comparative machinability of the various types of beryllium.

The thermal decomposition of the higher oxides of praseodymium and americium have been investigated.

Memorandum presenting measurements of some of the high-speed characteristics of the D-558-1 airplane up to Mach number 0.89. The results of the tests showed that the stabilizer incidence drastically affected the longitudinal trim characteristics above a Mach number of 0.80.

Note presenting a theory of plasticity based on the concept of slip as proposed for the relationship between stress and strain for initially isotropic materials in the strain-hardening range. The theory is an extension to polyaxial stress conditions of the conventional uniaxial stress-strain relation, and time-dependent effects, such as creep and stress relaxation, are not considered.

"A general algebraic method of attack on the problem of controlling gas-turbine engines having any number of independent variables was utilized employing operational functions to describe the assumed linear characteristics for the engine, the control, and the other units in the system. Matrices were used to describe the various units of the system, to form a combined system showing all effects, and to form a single condensed matrix showing the principal effects. This method directly led to the conditions on the control system for noninteraction so that any setting disturbance would affect only its corresponding controlled variable" (p. 581).

Report presenting the results of a total of 109 tests to evaluate certain characteristics of six ceramic oxide bodies for high-temperature applications, especially as turbine blades. The primary emphasis was placed on determinations of strength and resistance to creep under tensile strength at elevated temperatures. Results regarding step tests, short-time tensile tests, stress-rupture test results, modulus of elasticity, correlation of absorption and extension, stress-temperature-time effects, and general evaluation of bodies are provided.

Resolution of the products of the reactions of DPN and ATP with ultraviolet light by techniques of partition paper chromatography is reported in this paper.

Abstract: A procedure for the preparation of the nitrides and carbides of several metals and the preparation of the refractory bodies from them is described. The investigation shows that reasonably strong and dense bodies can be prepared from these materials as well as from UO₂. Evidence showing the tendency toward instability at high temperatures of Be₃N₂, TaN, and ThN is presented. Evidence is also given indicating that the hexagonal structure reported by others for TaN is actually that for Ta₂N. A lattice for Th₂N₃ is proposed. The melting points of ThN, UN, and UC are determined to be 2630 ± 50°C,2650 ± 100°C, and 2590 ± 50°C respectively.

Measurements have been made of the mean total-head and temperature fields in a round turbulent jet with various initial temperatures. The results show that the jet spreads more rapidly as its density becomes lower than that of the receiving medium, even when the difference is not sufficiently great to cause measurable deviations from the constant-density, dimensionless, dynamic-pressure profile function. Rough analytical considerations have given the same relative spread. The effective "turbulent Prandtl number" for a section of the fully developed jet was found to be equal to the true (laminar) Prandtl number within the accuracy of measurement. (author).

Note presenting a study of the properties of a large forged disc of Inconel X alloy at room temperature, 1200, 1350, and 1500 degrees Fahrenheit in order to determine the level of properties obtainable in a forging of this type required for the rotor discs of gas turbines. Results regarding the hardness survey, short-term tensile properties, Charpy impact resistance, rupture test characteristics, time-deformation characteristics, creep strengths, stability characteristics, and comparison of properties of Inconel X with single and double aging treatments are provided.

Report discussing three fuels conforming to AN-F-58 specification were investigated in order to determine the influence of boiling temperatures and aromatic content on altitude performance in single combustor of a 4600-pound-thrust turbojet engine.

"The present report of Mr. Dupleich is the summary of a very extensive experimental study of the well-known mechanical phenomenon: the rotation in free fall (* air, for instance) of more or less elongated rectangles cut out of paper or pasteboard. This phenomenon, the conditions for existence of which depend chiefly on the elongated of the small plate and its weight per unit area, is essentially an aerodynamic phenomenon and as such, raises questions of a certain interest to our department. We believe that the modern concepts of the mechanics of fluids do not have the range attributed to them" (p. 1).

"In the present paper, the motion of a gas in a plane-parallel Laval nozzle in the neighborhood of the transition from subsonic to supersonic velocities is studied. In a recently published paper, F. I. Frankl, applying the holograph method of Chaplygin, undertook a detailed investigation of the character of the flow near the line of transition from subsonic to supersonic velocities. From the results of Tricomi's investigation on the theory of differential equations of the mixed elliptic-hyperbolic type, Frankl introduced as one of the independent variables in place of the modulus of the velocity, a certain specially chosen function of this modulus" (p. 1).

Report presenting a wind-tunnel investigation at low Mach and Reynolds numbers to determine the high-lift and lateral control characteristics of a semispan wing of NACA 65(sub 2)-215 airfoil section equipped with a 25-percent-chord, full-span, slotted flap and plug and retractable ailerons. The ailerons were located at the 70-percent-chord station over the outer 49 percent of the wing semispan and were fabricated in five spanwise segments. Results regarding the wing aerodynamic characteristics, lateral control characteristics, comparison of lateral control characteristics of the plug and retractable ailerons, and a comparison of lateral control characteristics of the plug and retractable ailerons on the present wing with similar ailerons on an NACA 65-210 wing are provided.

Report presenting an investigation of the performance and general operating characteristics of a small single-cylinder, two-stroke-cycle, loop-scavenged engine using compression ignition at low compression ratios, high inlet-manifold temperatures and high inlet-manifold and exhaust-gas pressures. Results regarding the scavenging characteristics, power output, cylinder pressures, thermal efficiency, and exhaust measurements are provided.

Monthly report of the U.S. Geological Survey's trace element investigations including an outline of field work, laboratory work, and staff activities that have been completed or are in process.

Wind tunnel tests of the 0.16-scale Douglas MX-656 model were made at low and high subsonic Mach numbers to investigate the static longitudinal- and lateral stability characteristics. The tests shows that undesirable changes in longitudinal stability at the stall were apparently caused by an altered downwash pattern at the tail. The jettisonable nose fins were highly destabilizing. Compressibility effects for the test Mach numbers were not detrimental to the longitudinal- or lateral-stability characteristics.

Note presenting general methods of solution for the two- and three-dimensional steady-state and two-dimensional unsteady-state equations. Four applications of the general solutions are given.

Report presenting the theory for calculating the free-space oscillating pressures associated with a rotating propeller at any point in space. Good agreement was found between analytical and experimental results using this method. Results regarding vibration and sound levels in the fuselage in relation to pressure level are reported.

Report presenting a comparison between the calculated design performance of a gas-turbine stator blade and its performance in a sector of an annular cascade tunnel. The gas velocities on the blade surface were computed by the stress filament method and compared with experimental values, with which they agreed satisfactorily. Results regarding discharge angle, vane-surface-velocity distribution, tangential- and axial-velocity distribution, and radial-equilibrium consideration are provided.

"Lately it has been proposed to reduce the friction drag of a body in a flow for the technically important large Reynolds numbers by the following expedient: the boundary layer, normally turbulent, is artificially kept laminar up to high Reynolds numbers by suction. The reduction in friction drag thus obtained is of the order of magnitude of 60 to 80 percent of the turbulent friction drag, since the latter, for large Reynolds numbers, is several times the laminar friction drag. In considering the idea mentioned one has first to consider whether suction is a possible means of keeping the boundary layer laminar" (p. 1).

Memorandum presenting a study of a body of revolution with an NACA 1-50-100 nose inlet at zero angle of attack and no internal air flow to study the pressure drag of an extremely blunt-nose body and comparison with previous results for a sharp-nose body. The change from sharp to inlet nose while maintaining the same afterbody shape decreased the drag-rise Mach number from 0.94 to 0.90.