Note presenting some calculations made on the basis of simplifying assumptions to determine the effect on the ground-run distance of maintaining a nose-high attitude instead of a three-point attitude in landings of several types of jet airplanes on slippery runways. The airplanes considered were a swept-wing transport and unswept-, swept-, and delta-wing fighters. Results regarding the effect of airplane attitude and effect of flap retraction are provided.

Report presenting an investigation to determine the induced effect of sweep on an axial-flow compressor blade. Results regarding the blade-section pressure distributions, matching pressure distributions, comparison of turning angles in compressor and cascade, corrected turning angles, and normal-force coefficients are provided.

"Some results on the effects of wing flexibility on wing bending strains as determined from flight tests of a Boeing B-29 and a Boeing B-47A airplane in rough air are presented. Results from an analytical study of the flexibility effects on the B-29 wing strains are compared with the experimental results. Both the experimental and calculated results are presented as frequency-response functions of the bending strains at various spanwise wing stations to gust disturbances. In addition, some indirect evidence of the effect of spanwise variations in turbulence on the response of the B-47A airplane is presented" (p. 1).

"Equations are derived which evaluate the effects of thermal vibrational relaxation and specific-heat changes on pneumatic-probe pyrometer measurements in the region 1000 to 3000 degrees K and Mach numbers between 0.3 and 2.0. Examples are given for typical probes in two combustion mixtures" (p. 1).

Report presenting a method by which incremental pitching moments can be estimated for swept and triangular wings with arbitrary types of trailing-edge high-lift flaps. Span-loading theory is combined with two-dimensional airfoil data adjusted for the effects of sweep.

Note presenting an experimental investigation of the attenuation of strong shock waves in air in a shock tube. Time-history measurements were made of the static pressure at several stations in the wall of the tube. Hydrogen and helium were used as driver gases. A helium-driven shock wave was found to decay only about one-half as rapidly as a hydrogen-driven shock wave.

Report presenting flight testing of a fin-stabilized parabolic body of revolution (NACA RM-10) as a rocket-propelled model. Boundary-layer static-temperature profiles were determined around the body and from Mach number profiles obtained from a total-pressure rake. Results regarding boundary-layer profiles, skin-friction coefficients, and heat-transfer coefficients are provided.

Wind-tunnel tests were conducted to determine the ground effects on a tailless model with a wing of aspect ratio 2 and infinite taper, and on a tailed model with a triangular wing of aspect ratio 3, with flaps. Control-surface hinge moments were measured on the tailless model. The results are compared with the predictions of the theory of Tani, et al.

"The various factors governing buckling of flat plates are critically reviewed and the results are summarized in a comprehensive series of charts and tables. Numerical values are presented for buckling coefficients of flat plates with various boundary conditions and applied loadings. The effects of plasticity are incorporated in non dimensional buckling charts utilizing the three-parameter description of stress-strain curves" (p. 1).

"The local buckling of stiffener sections and the buckling of plates with sturdy stiffeners are reviewed, and the results are summarized in charts and tables. Numerical values of buckling coefficients are presented for longitudinally compressed stiffener sections of various shapes, for stiffened plates loaded in longitudinal compression and in shear, and for stiffened cylinders loaded in torsion. Although the data presented consist primarily of elastic-buckling coefficients, the effects of plasticity are discussed for a few special cases" (p. 1).

"The local buckling of stiffener sections and the buckling of plates with sturdy stiffeners are reviewed, and the results are summarized in charts and tables. Numerical values of buckling coefficients are presented for longitudinally compressed stiffener sections of various shapes, for stiffened plates located in longitudinal compression and in shear, and for stiffened cylinders loaded in torsion. Although the data presented consist primarily of elastic-buckling coefficients, the effects of plasticity are discussed for a few special cases" (p. 1).

Note presenting testing of twenty-seven structural joint specimens of 2024-T3 and 2024-T4 aluminum alloy consisting of a T-stringer riveted to a 10- by 10-inch skin surface under simulated aerodynamic heating with no external loading applied. Rivet size and pitch were found to influence the conductance but the rivet materials tested had no observable effect.

Report presenting an investigation of the discharge and force characteristics of a group of flapped auxiliary air outlets, rectangular in cross section, over a range of Mach numbers. The results of the investigation are presented in a series of design charts. Results regarding design charts and a comparison of experimental with calculated thrust are provided.

"The minimization of wave drag for thin aerodynamic shapes carrying no lift is studied for conditions under which either base area or volume is specified. When volume alone is given, the analysis is limited to shapes with straight trailing edges normal to the stream direction. The problem of minimization is reduced to one of finding a two-dimensional harmonic function with known boundary conditions" (p. 1).

Report presenting an analysis of the overall sound-pressure levels and frequency spectra of the noise emitted from a full-scale, 7.2-foot-diameter, 3500-rpm, three-blade, supersonic propeller mounted on a turbine-powered airplane under static conditions at stations about the propeller at a 100-foot radius. Variations in power produced the variations in overall sound-pressure levels predicted by theory.

Report presenting a determination of ignition delays and combustion efficiencies for propane injected into a heated airstream. Two types of flames were observed for multipoint fuel injectors: a diffusion flame that stabilized at the injector orifices and an ignition-stabilized flame that formed a flame front downstream of the fuel injector. Results regarding combustion of injector-stabilized flames and combustion of ignition-stabilized flames are provided.

Report presenting an analysis based on droplet-evaporation theory, which shows that for a given combustor length, the percent of fuel mass vaporized can be increased by decreasing the fuel-drop size and initial drop velocity, or by increasing chamber pressure, final gas velocity, and initial fuel temperature. The results were correlated to give a single curve of percent of fuel evaporated as a function of the chamber length and the factors involving the parameters.

Report presenting the results of research on the creep of airframe components at elevated temperatures. Experimental lifetime data from creep tests of stainless-steel plates and aluminum-alloy unstiffened circular cylinders are presented and compared with results predicted from isochronous stress-strain curves.

Report presenting testing of the use of screens placed across the jet as a means of suppressing jet noise during ground running, which was somewhat offset by increased noise levels ahead of the engine. Air-jet tests showed negligible reduction in sound generation with additional screens. The large reductions obtained by using screens show that noise generated inside the engine by the turbine or combustion contribute only a minor part of the total noise.

Note presenting exploratory tests of the stress-corrosion cracking of single crystals of solution-treated AZ61X magnesium alloy in distilled water, in hydrofluoric acid, and in a salt-chromate solution. The results of this paper show that failures often start and run on planes other than the basal plane and are inconsistent with previously generated hypotheses. Results regarding the pilot tests on polycrystalline specimens and single-crystal tests are provided.

A discussion of the acoustic fatigue problem of aircraft structures along with data pertaining to the acoustic inputs from some power plants in common use. Comparisons are given for results of fatigue tests of flat panels and cantilever beams exposed to random- and discrete-type inputs. Both the stress level of the test and type of model are significant, so no generalizations can be made at this time.

Report presenting an investigation to determine the effects of horizontal-tail location and size on the longitudinal aerodynamic characteristics of an airplane model with a triangular wing. The horizontal tail was found to be destabilizing at moderate lift coefficients when located above the plane of the wing. Results regarding the longitudinal stability and control characteristics and drag characteristics are provided.

Report presenting a wind-tunnel investigation to determine the low-speed aerodynamic characteristics of an airplane arrangement with an unswept horizontal tail and triangular wing of aspect ratio 3 equipped with partial-span single-slotted flaps and plain ailerons. The effects of flap deflections on the longitudinal characteristics were investigated for several tail positions. Results regarding the effects of single-slotted flaps, lateral control effectiveness with the flaps down, and effect of small flap deflections at Mach numbers up to 0.95 are provided.