Spanwise lift distributions have been calculated for nineteen unswept wings with various aspect ratios and taper ratios and with a variety of angle-of-attack or twist distributions, including flap and aileron deflections, by means of the Weissinger method with eight control points on the semispan. Also calculated were aerodynamic influence coefficients which pertain to a certain definite set of stations along the span, and several methods are presented for calculating aerodynamic influence functions and coefficients for stations other than those stipulated. The information presented in this report can be used in the analysis of untwisted wings or wings with known twist distributions, as well as in aeroelastic calculations involving initially unknown twist distributions.

Report presenting testing of a flat-bottom V-step model with a beam loading of 4.6 subjected to fixed-trim impacts in smooth water. Testing occurred at three different trim angles and a range of initial flight-path angles. Data were obtained as time histories of draft, vertical velocity, and vertical acceleration. The results are presented as plots of nondimensional lift, draft, vertical velocity, and time against flight-path angle at contact.

"The results of an experimental investigation of the strength of plane diagonal-tension webs with ratios of web depth to web thickness of about 60 are presented. An analysis of the beam indicated that the methods of strength analysis presented in NACA TN 2661 are applicable to beams with flanges symmetrically arranged with respect to the web if the portal-frame effect is taken into account" (p. 1).

Note presenting pressure distributions measured on a model helicopter rotor blade under hovering and simulated forward-flight conditions. Pressure were recorded at advance ratios of 0.10, 0.22, 0.30, 0.40, and 0.50 for a zero-offset flapping-hinge rotor and at 0.10, 0.22, 0.30, 0.45, 0.60, 0.80, and 1.0 for a lifting rotor with a flapping-hinge offset of 13 percent.

Report presenting a new shadowgraph technique for the observation of conical flow phenomena in supersonic flow. The particular advantage of this technique is that it permits observation of the conical flow phenomena in a plane normal or nearly normal to the axis of propagation. Results regarding cones and triangular wings are provided.

Note presenting flight tests made with a typical light airplane to investigate possibilities for obtaining reliable control at low flight speeds. An attempt was made to find a configuration that would provide sufficient elevator control for a three-point landing under the most critical condition and that would also have insufficient elevator control to exceed the angle of attack at which reliable lateral control is obtained in flight under all of the center-of-gravity and power conditions.

Report discussing a new high-speed photographic technique, which employs a variable-frequency light synchronized with a commercially available 16-millimeter high-speed motion-picture camera without appreciable alterations to the camera. The technique is described and results obtained by the technique of photographing the flow past models in a wind tunnel with the schileren method of flow visualization are presented.

"High operating temperatures of new and projected turbine engines require that synthetic fluids be used as lubricants, because these fluids have better thermal stability and viscosity-temperature characteristics than petroleum oils have. An experimental study was conducted to learn the effect of high lubricant bulk temperatures on the boundary lubricating effectiveness of various types of synthetic fluid" (p. 1).

The creep of single crystals of high-purity aluminum was investigated in the range of temperatures from room temperature to 400 F and at resolved-shear-stress levels of 200, 300, and 400 psi. The tests were designed in an attempt to produce data regarding the relation between the rate of strain and the mechanism of deformation. The creep data are analyzed in terms of shear strain rate and the results are discussed with regard to existing creep theories.

Note presenting fatigue data for 76S-T61 aluminum alloy for several combinations of bending and torsion with both alternating and mean stresses. The literature on the effect of combined stress and of mean stress in fatigue is reviewed and the results of the present series are compared with those of various theories. Results regarding fatigue data, fatigue fractures, and static tests are provided.

Report presenting static force-deflection tests on six aircraft tires ranging in size and ply rating. Testing included the vertical loading of all six tire specimens and, for five of the tire specimens, combined vertical loading and side loading and combined vertical loading and torsional loading.

Note presenting experimentally determined influence coefficients for the deflection of two solid delta wings - one wing of constant thickness and the other of constant thickness ratio - with a carry-through-bay chord smaller than the wing root chord. The experimental tip-load deflections of the constant-thickness wing exceed those computed by the present theory by approximately 15 to 20 percent at the tip.

An analytical investigation of incompressible flow about wedges was made to determine effects of tunnel-wedge ratio and wedge angle on the wedge pressure distributions. The region of applicability of infinite wedge-type velocity distribution was examined for finite wedges. Theoretical and experimental pressure coefficients for various tunnel-wedge ratios, wedge angles, and subsonic Mach numbers were compared.

Attenuation characteristics of four different resonator mufflers were determined in both cold tests and engine field tests and compared with the theoretical calculations. These mufflers were specifically designed for a helicopter. Engine-exhaust sound pressures, temperatures, and noise levels from the helicopter were measured. The experimental muffler cold tests indicated close a agreement with theory, whereas the engine tests indicated some discrepancies. Test results show the usefulness of the theoretical equation used for predicting muffler attenuation characteristics.

Report presenting results of experimental measurements of low-frequency combustion instability of a 300-pound-thrust acid-heptane rocket engine as compared with the trends predicted by an analysis of combustion instability in a rocket engine. Results regarding the chugging frequency, combustion time delay, effect of rocket combustion-chamber characteristic length, effect of throttling, effect of injection velocity, effect of oxidant-fuel ratio, variation of chugging frequency with amplitude of chamber pressure fluctuations, and evaluation of the analysis are provided.

Memorandum presenting an icing investigation conducted to determine the general de-icing and runback characteristics of three production samples of electric rubber-clad cyclic de-icing boots. The overall de-icing characteristics of two of the boots investigated were quite similar. Results regarding boot surface temperatures and general de-icing and runback characteristics are provided.

"The trajectories of droplets in the air flowing past NACA 65(1)-208 airfoil and an NACA 65(1)-212 airfoil, both at an angle of attack of 4 degrees, were determined. The amount of water in droplet form impinging on the airfoils, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface affected were calculated from the trajectories and are presented. The amount, extent, and rate of impingement of the NACA 65(1)-208 airfoil are compared with the results for the NACA 65(1)1-212 airfoil" (p. 1).

Report presenting an investigation to increase the compressor surge-limit pressure ratio of the XJ40-WE-6 turbojet engine at high equivalent speeds. The two compressor modifications investigated included twisting rotor blades to change blade section angles and inserting new stator diaphragms with different blade angles. Results regarding the effect of surge limit on engine performance, performance map of original compressor with mixer, effect of blade modifications on surge line, effect of mixer on surge limit, and effect of compressor modifications on performance are provided.

Report presenting results of a flight investigation using a jet-powered bomber airplane to determine the vertical tail loads. Strain-gage measurements were made of the fin and rudder loads in abrupt rudder kicks and in gradual sideslip maneuvers.

Report presenting data obtained three single annular-type combustors with different combustor inlet-air pressure profiles over a range of engine speeds. Results regarding effect of changing combustor inlet-air pressure profile and hole geometry on combustor performance, performance of the prototype J40-WE-8 turbojet engine combustor, correlation of combustion efficiency with engine fuel-air ratio and combustion parameter, and comparison of several combustors from different turbojet engines are provided.

Report presenting a vibrational survey conducted during normal operation of a production eleven-stage axial-flow compressor powered as part of a complete turbojet engine. After serious third-stage vibration was detected, an investigation was conducted to study and eliminate the vibration with several component configurations. The vibrational source was determined to be an aerodynamic phenomenon related to a stall, but a new inlet-guide-vane assembly with a 4-percent increase in inlet area eliminated the vibration and increased the engine thrust 4 percent.

Report presenting an investigation in the high-speed tunnel for a range of Mach numbers to determine the lateral control characteristics of a wing-fuselage combination with the wing quarter-chord line swept back 32.6 degrees, an aspect ratio of 4, a taper ratio of 0.6, and an NACA 65A006 section. Results regarding yawing-moment characteristics, spoiler-slot-deflector testing, and rolling-moment coefficient are provided.

Report presenting measurements of the intensity of buffeting experienced by the Douglas D-558-II research airplane at a range of Mach numbers. Buffeting was encountered at both subsonic and supersonic Mach numbers and the intensity of the buffeting varied with Mach number and airplane normal-force coefficient.

Report presenting an investigation to determine the effects of plan-form taper on the aerodynamic characteristics of a series of symmetrical, unswept wings with thicknesses of 8-percent chord. The wings were tested with four different bodies of revolution over a range of Mach numbers. Results regarding the lift, drag, pitching-moment, lift-curve slope, lift-drag ratio, and pitching-moment curve are provided.