Report presenting an investigation to determine the effect of heat transfer on the peak pressure rise associated with the separation of a turbulent boundary layer on a body of revolution at Mach number 1.61. The results indicated that little or no effect of heat transfer on the shock angles associated with separation on the peak pressure rise required to separate a turbulent boundary layer.

Note presenting tests on a power control system by means of a ground simulator to determine the effects of various combinations of valve friction and stick friction on the ability of the pilot to control the system. The results show that, when valve friction was present in a rigid system, the introduction of stick friction was beneficial in that it restored some of the quality lost because of the valve friction. Results regarding the rigid control system, flexible control system, and control system with backlash are provided.

Note presenting equilibrium temperatures and heat-transfer rates for 0.00015- and 0.00030-inch diameter tungsten wires normal to the flow throughout a range of Mach numbers and Reynolds numbers. For the range of variables, equilibrium temperature of the hot wire is characterized by constant recovery factor for subsonic Mach numbers but constant equilibrium to total temperature ratio for supersonic Mach numbers. Results regarding the equilibrium temperature tests and heat-transfer tests are provided.

The 100-hour rupture strengths of Inconel X, Inconel 700, Incoloy 901, Refractaloy 26, and R-235 at 1200 and 1350 F. in both the annealed and heat-treated conditions were determined. Inconel 700 had the highest rupture strength at both temperatures; Incoloy 901 was second strongest at 1200 F, and R-235 second strongest at 1350 F. With the exception of Incoloy 901, ductility was low. Photomicrographs show that fractures are through the grain boundaries. Results are compared with published data for other sheet alloys and bar stock.

"Stability limits for laminar and turbulent hydrogen-air burner flames were measured as a function of pressure, burner diameter, and composition. On the basis of a simple flame model, turbulent flashback involved a smaller effective penetration distance than laminar flashback. No current theoretical treatment predicts the observed pressure and diameter dependence of laminar and turbulent blowoff" (p. 1).

A double set of turning vanes was carried inside the jet tailpipe. To produce reverse thrust, the tailpipe opens into two side sections and the turning vanes move outward to form a V-shaped cascade, which deflects the exhaust-gas flow. Forward and reverse net thrust were measured over a range of engine speeds with the airplane stationary. Taxi tests were made to determine the comparative stopping distances using wheel braking and reverse thrust separately, and a combination of both. The effect of turning-vane spacing on thrust-reverser performance was determined by scale-model tests using unheated air.

Report presenting methods for determining the linearized subsonic flow about symmetrical, nonlifting wing-body combinations. A comparison of theory and experiment is made for two 45 degree sweptback wings in combination with basic Sears-Haack bodies of revolution and in combination with basic bodies indented according to the transonic area rule.

The sound pressures radiating from the exhaust streams of two convergent-divergent and one convergent nozzle were measured. Exit diameters were 1.206 in. for the expanded nozzle and 0.625 in. for the convergent nozzle. The results are presented in a series of contour maps of overall and fine 1/3-octave-band sound pressures. The location of the source of the noise in each 1/3-octave band in the frequency range of 30 to 16,000 cps and the total power radiated were determined and compared with those of subsonic jets.

From Summary: "A semivaneless turbine stator designed to eliminate blade wakes and secondary-flow accumulations of boundary-layer air was built and tested. Performance of this stator was evaluated with static pressures measured in the vaneless section and surveys of total pressure and flow angle made at the stator exit. Results are presented in terms of theoretical and experimental velocities and flow angles, boundary-layer parameters, and contours of total-pressure loss across the stator."

Results from an experiment indicated that the ignition of hydrogen-oxygen gas mixtures at a pressure of 1 atmosphere in a 2-foot-diameter duct resulted in detonation combustion. The use of a duct for the rocket exhaust may permit a reduction of the noise output and allow for the cooling and chemical treatment of the exhaust gases. The use of water jets and water sprays distributed through the duct did not prevent a detonation but did reduce peak pressure.

Note presenting the results of a detailed study of the flutter characteristics of four representative aircraft wings. During the investigation, eight important parameters of each wing were varied and the effects of mass, inertia, pitching spring, and location of a concentrated mass for all four wings and several sweepback angles.

Note presenting testing of geometrically related structural joints representing typical skin-stringer cross sections under radiant heating to simulate the effects of aerodynamic heating. The presence of an interface was found to have a significant effect on the temperature distribution in all geometries tested and thus must be considered in temperature calculations. Interface conductance values were computed for each of the 15 fabricated specimens.

A discontinuous variation of coefficients of the differential equation describing the linear control system before nonlinear elements are added is studied in detail. The nonlinear feedback is applied to a second-order system. Simulation techniques are used to study performance of the nonlinear control system and to compare it with the linear system for a wide variety of inputs. A detailed quantitative study of the influence of relay delays and of a transport delay is presented.

Note presenting an analysis and comparison of atmospheric turbulence as experienced by rocket-powered models and temperature lapse-rate data obtained from rawinsonde soundings in 38 cases by using an assumed temperature lapse-rate stability boundary as a basis for comparison. A limited correlation has been obtained which indicates that atmospheric conditions classified as being unstable will generally be turbulent, but a marginal or stable classification does not necessarily indicate smooth air.

Report presenting the zero-lift damping-in-roll derivative as experimentally determined through high subsonic, transonic, and low supersonic speeds by a torque-nozzle forced-roll technique utilizing rocket-propelled models. Data from the the investigations is used to show the effects of wing plan form and airfoil section and the effects of aeroelasticity. Results regarding sweepback, aspect ratio, taper ratio, thickness ratio, airfoil-section shape, delta wings, increase in number of semispan wings from three to four, aeroelastic effects, and comparisons with theory are provided.

Note presenting tables of Mach number functions for a range of specific-heat ratios compiled for use at the Lewis laboratory for solving fluid-flow problems.

The proximity of the ground to an annular nozzle can result in thrust augmentation of up to 50 percent. The magnitude of thrust augmentation was a function of ground-to-nozzle distance, nozzle configuration, and nozzle pressure ratio. With a conventional circular nozzle a thrust reduction of 15 to 40 percent due to ground effect was obtained. The degree of thrust reduction was primarily a function of nozzle pressure ratio and ground-to-nozzle distance.

The statistical approach to the gust-load problem which consists in considering flight through turbulent air to be a stationary random process is extended by including the effect of lateral variation of the instantaneous gust intensity on the aerodynamic forces. The forces obtained in this manner are used in dynamic analyses of rigid and flexible airplanes free to move vertically, in pitch, and in roll. The effect of the interaction of longitudinal, vertical, and lateral gusts on the wing stresses is also considered.

Note presenting internal-pressure tests made on aluminum-alloy unstiffened cylinders with precut slits to study the effect of slit length and curvature on the hoop stress developed at the bursting pressure. The results are predicted with good accuracy by applying a curvature correction to the method presented in a previous report for computing the strength of flat plates with cracks.

Results are presented from a hydrodynamic investigation of the inception of vortex ventilation on modified-flat-plate rectangular lifting surfaces of aspect ratio 0.25 differing in scale and thickness ratio. Two types of bubble-formation processes are described. Inception speeds were correlated for bubble formation in the high angle-of-attack range by using the Froude number and for that in the low angle-of-attack range by expressing the speed as a function of the thickness ratio.

Results of an investigation of the hydrodynamic characteristics over an extended speed range of a rectangular modified flat plate having an aspect ratio of 0.25 and operating at several depths of submersion are presented. Comparisons between these data and data over a lower speed range on a similar aspect-ratio-0.25 flat plate but having one-half the thickness are presented. These comparisons show no significant differences at the low speeds. At high speeds and high angles of attack, where extensive cavitation was present, the lift coefficients were lower than would have been indicated by the results of the previous investigations and the present investigation at the lower angles of attack. A brief discussion and comparison of ventilation are presented which shows two types of planing bubble formation and the effect of increasing the thickness of the model on the ventilation boundary.

Memorandum presenting the effect of missile armament on the performance of an interceptor-type aircraft model at Mach numbers 1.5, 1.7, and 1.9 and at angles of attack up to 19 degrees. The aircraft model was characterized by triangular-shaped normal-shock inlets located at wing roots. Results regarding force measurements, effect of armament on inlet-duct performance, fuselage boundary-layer survey, and total-pressure contours at inlet throat and diffuser exit are provided.

Report discussing a project to determine a high-energy fuel suitable for turbojet-powered aircraft. Components of the project include thermal and combustion properties, experiments with combustors using boron compounds, evaluation of boron fuels in full-scale turbojets with and without afterburners, and boron fuel use in ramjet flights. The most promising fuel found in the report is pentaborane.

Flight investigation of pentaborane fuel in 9.75- inch-diameter ramjet engine with downstream fuel injection.