Report presenting an investigation of the rolling-stall characteristics of a 0.9 hub-tip ratio rotor. Stall patterns consisting of two, three, and one total-span stall zones developed in that order upon reduction of flow coefficient. Results regarding performance and stall characteristics, rotor pressure-rise coefficient, flow fluctuations due to rotating stall, pressure fluctuations due to rotating stall, temperature fluctuations due to rotating stall, and discussion of rotating stall and comparison with theory are provided.

Report presenting a description of a concentric-cylinder rotational viscometer that is capable of recording meaningful flow curves of rate of shear against shearing stress for most non-Newtonian materials.

Report presenting results of a 35 degree swept-wing fighter airplane during lateral oscillations over a range of Mach numbers and pressure altitudes. Experimental and computed values for the period of the lateral oscillation and time required to damp to half amplitude are shown. Results regarding typical time histories, some of the data obtained, oscillatory characteristics, and flying characteristics are provided.

Report presenting investigations in the gust tunnel to determine the effects of a sharp-edge vertical gust on the blade flapwise vibratory bending moments of small model rotors having either fixed-at-root or teetering blades. Both rotor configurations were tested up to a tip-speed ratio of about 0.35. Results regarding frequency diagrams and strain records, fixed-at-root condition, teetering condition, effect of rotor speed, and comparison of mean and vibratory blade bending moments are provided.

Note presenting analyses based on theoretical results of another report to determine the plan forms of unbalanced trailing-edge flap-type controls with minimum hinge moments due to deflection and requiring minimum work to overcome the hinge moments due to deflection at supersonic speeds. Ratios of lift and rolling moment due to hinge moment and ratios of lift and rolling moment to deflection work at fixed values of lift and rolling effectiveness were used as bases for the analyses.

"The flow in a rectangular cavity, or slot, in the floor of a wind tunnel is described by the results of pressure and velocity measurements. Pressure distributions on the cavity walls as well as measurements of friction are presented. The effects of varying depth-breadth ratio are shown" (p. 1).

A review of the available information on the spectrum of atmospheric turbulence. A method based on these results is developed for the conversion of available gust statistics given in terms of counts of gust peaks into a form appropriate for use in spectral calculations. Some results that vary with types of operations are also provided.

Flame propagation limits of propane and n-pentane in oxides of nitrogen were obtained at subatmospheric pressures in a 2-inch-diameter by 48-inch-length tube. Flames propagated through all of the fuel-oxidant mixtures.

Report presenting an examination of the problem of determining the shape of slender boattail bodies of revolution for minimum wave drag. To eliminate the restriction involving the class of bodies used in Ward's slender-body drag equation, certain higher order terms must be retained in the drag equation and isoperimetric relations. The resulting body shapes have slightly less drag than those determined by previous investigators.

Note presenting an investigation initiated in the 20-foot free-spinning tunnel to study the gyroscopic effects of jet-engine rotating parts on the erect spin and spin-recovery characteristics. A model of a military attack airplane was arbitrarily used and tests were made at basic and alternative loadings.

Report presenting the results of a theoretical and experimental study of ramjet diffuser flow pulsing, commonly referred to as a buzz condition, with and without combustion. The acoustical resonance properties of ram jets are an important factor in establishing the frequency of diffuser flow pulsations.

From Introduction: "The experiments in high-speed flow showed that an intense, high-frequency acoustic radiation is an essential feature of the problem. Consequently, a study of the acoustic field (involving schlieren observations and frequency and intensity measurements) was undertaken. This report presents the salient features of the study, which was mainly exploratory."

Note presenting the effects of interaction between a landing gear and a flexible airplane structure on the behavior of the landing gear and loads in the structure, which have been studied by treating the equations of motion of the airplane and the landing gear as a coupled system. Numerical calculations based on the structural properties of two large airplanes with considerably different mass and flexibility characteristics are presented.

Report presenting wind-tunnel testing a Mach number 4.04 to determine the effects of leading-edge sweep, angle of attack, and leading-edge thickness on boundary-layer transition on flat-plate wings. Results regarding factors which can affect boundary-layer transition, effect of the boundary-layer plate, luminescent-lacquer technique, model surface condition, stream turbulence level, heat-transfer effects, effects of leading-edge thickness, effects of leading-edge sweep and angle of attack, variations of transition Reynolds number with pressure, and effects of changes in wing section are provided.