"Theoretical design charts based on Neuber's equations for symmetrically located notches are presented for estimating the approximate rupture strengths of blade roots made from brittle materials. The limit of applicability of the theoretical charts is shown as determined by rupture tests of plastic models. The optimum proportions among over-all root width, neck width, notch radius, and notch depth are determined from the design charts" (p. 1).

Report presenting an investigation in the transonic tunnel on a submerged inlet with a divergent-walled approach ramp to determine flow phenomena, pressure recovery, and external forces to provide correlation with available data obtained on similar inlets. Results regarding the pressure characteristics, aerodynamic forces, and performance comparisons are provided.

Memorandum presenting an investigation of the performance of inlet configurations with a forebody designed for isentropic external compression at a nominal Mach number of 5.6. At zero angle of attack, all of the configurations yielded larger total-pressure recoveries than had previously been obtianed with a single-conical-shock inlet. Results regarding the flow about the forebody and performance comparisons are provided.

Report presenting the effect of channel geometry on flame quenching, as calculated on the basis of average active particle chain lengths, is related among six different geometries: plane parallel plates of infinite extent, cylindrical tubes, rectangular slots, cylindrical annuli, and tubes of elliptical and equilaterally triangular shape. The results indicated that the observed variation of flame quenching as a function of quenching geometry may be successfully predicted for a range of pressures and for rich as well as lean propane-air flames.

Report describing a supersonic-compressor rotor designed as an impulse-type with some deceleration along the tip and with turning to the axial direction. Results regarding the overall performance, inlet flow distribution, results of rotor-outlet surveys, blade element performance at 90 percent design speed, and blade element performance at open throttle are provided.

"Ignition of the fuel-air mixture in an afterburner of turbojet engine at altitude has often proved to be a different problem to solve. Electrical ignition has not proven satisfactory because of the unreliability of such systems (ref. 1). The ignition data reported herein were obtained for two after-burner configurations. Autoignition data are included for both configurations and hot-streak-ignition data, for only one. "

Memorandum presenting flight tests on a swept-wing fighter airplane at a range of Mach numbers, which indicate the critical flight regions for balancing, maneuvering, and buffeting horizontal-tail loads. The critical balancing tail loads were found to occur at the highest test Mach number of about 1.03 at the highest airplane load factor. Results regarding balancing tail loads, maneuvering tail loads in elevator-pulse maneuvers, maneuvering tail loads in pitch-up maneuvers, buffet tail loads, and tail-load distributions are provided.

Report presenting an experimental investigation to determine the aerodynamic characteristics of a slender cone-cylinder body of revolution in the 1- by 1-foot supersonic wind tunnel. Viscous drag and three component forces were measured at Mach number 3.12 and a range of Reynolds numbers and angles of attack. Results regarding pressure distributions, boundary layer, and forces are provided.

Report presenting an investigation of two types of jet controls in the 8- by 6-foot supersonic wind tunnel. One used a converging swiveled nozzle and the other was a biconvex circular-arc vane mounted in a shroud and placed downstream of a convergent nozzle. Results regarding the jet vane, swiveled nozzle, and a preliminary evaluation are provided.

Report presenting an investigation of the hydrodynamic characteristics of a powered dynamic model of the Martin PBM-5 seaplane equipped with a single Edo hydro-ski. Various hydro-ski positions were investigated. Results regarding aerodynamic and hydrodynamic characteristics, including excess thrust, smooth-water landings, smooth-water take-offs, rough-water take-offs, and spray are provided.

Report presenting a determination of the combustion efficiency of gaseous hydrogen fuel in a ramjet engine in a connected-pipe test facility. Operating conditions simulated a range of Mach numbers and altitudes. Results regarding the effect of inlet parameters and design variables on combustion efficiencies, comparison between methods of determining efficiency, and ignition characteristics are provided.

Pressure distributions for a series of four boattailed bodies of revolution were obtained and compared with theory for a Mach number of 3.12, a Reynolds number range of 2 x 10 to 6th power to 14 x 10 to the 6th power, and angles of attack from zero to 9 degrees. Second-order theory adequately predicted the pressure distribution for regions free of the effects of cross-flow separation.

Report presenting an analysis and examination of a large volume of data from several recent stores-research programs. For a given wing plan form, store position and configuration of angle of attack have been shown to be the most important parameters in the evaluation of store side force.

Data obtained from the first flight test of a ram jet utilizing a magnesium slurry fuel are presented. The ram jet accelerated from a Mach number of 1.75 to a Mach number of 3.48 in 15.5 seconds. During this period a maximum values of air specific impulse and gross thrust coefficient were calculated to be 151 seconds and 0.658, respectively. The rocket gas generator used as a fuel-pumping system operated successfully.

Memorandum presenting four wings of different plan forms equipped with plain spoiler ailerons tested at low speeds. Three of the models had wings of aspect ratio 3 and different taper ratios and sweep of the quarter-chord lines, while the fourth had an aspect ratio of 4.8, a taper ratio of 0.51, and sweep of 35 degrees.

Report presenting four wings of different plan form equipped with plain spoiler ailerons tested at low speeds. Three of the models had wings of aspect ratio 3 and a range of taper ratios and sweep. The fourth model had aspect ratio 4.8 with taper ratio 0.51 and 35 degrees of sweep.

Report presenting the lift, pitching-moment, and drag characteristics of a missile configuration with a body of fineness ratio 9.33 and a cruciform triangular wing and tail of aspect ratio 4 at Mach number 1.99 and Reynolds number 6.0 million. Testing occurred over a range of angles of attack and to investigate the effects on the aerodynamic characteristics of roll angle, wing-tail interdigitation, wing deflection, and interference among the components.

Report presenting an investigation made in the stability tunnel to determine the effectiveness with which the dynamic characteristics of a low-speed slowly spinning fin-stabilized rocket could be studied by a free-oscillation technique and to study certain peculiarities of behavior. Results regarding the stability of the original model, effect of reversing direction of the arming propeller, effect of increasing size of reversed-rotation of the arming propeller, effect of removing the arming propeller, effect of adding a spoiler nose ring to the basic model, and the effect of changes in spin rate are provided.

Report presenting the results of an experimental investigation of the effect of leading-edge chord extensions on the aerodynamic characteristics of a wing-body-tail combination employing a 3-percent-thick triangular wing of aspect ratio 3 in conjunction with an unswept, all-movable, horizontal tail located below the wing-chord plane. Lift, drag, pitching moment, and hinge moment were measured a range of Mach numbers and a constant Reynolds number.

Memorandum presenting an investigation conducted in the 4- by 4-foot supersonic pressure tunnel to determine the effects of wing vertical location and geometric dihedral on the aerodynamic characteristics in pitch and sideslip of a wing-body configuration at Mach number 2.01. The configurations investigated included a high-wing, midwing, and a low-wing arrangement.

Report presenting a scale rocket-propelled model of the Convair XF2Y-1 water-based fighter airplane in free flight in a range of Mach numbers. Results regarding stability characteristics, trim characteristics, drag characteristics, and inlet and duct characteristics are provided.

Report presenting the results of an investigation to determine the dynamic stability and control characteristics of a delta-wing vertically rising airplane model powered by a ducted fan. The model had flap-type control surfaces on the wings and vertical tail as well as movable eyelids at the rear of the tail pipe and air bled from the main duct and exhausted through movable nozzles near the wing tips. The model was found to generally fly smoothly and easily without automatic stabilization devices.

Report presenting an investigation at low speed to determine the static aerodynamic forces and moments on a canard missile model during launching from the midsemispan and wing-tip locations of a wing-fuselage combination with a 45 degree sweptback wing. When the missile was mounted under the wing at the midsemispan location, changes in chordwise position produced large changes in missile forces and moments.

Report presenting an evaluation of data obtained with an automatic constant inlet-pressure control valve designed to facilitate the study of transient engine performance characteristics in the altitude wind tunnel. The engine characteristics obtained by use of the pressure valve were compared with those obtained with a bellmouth inlet operating in simulated free-stream conditions.