"The primary objectives of the present paper are to report the horizontal-tail-loads measurements for configuration B which have not previously been reported and to summarize the horizontal-tail-loads results obtained with both configurations. The manner in which the aerodynamic-loads data were analyzed to include structural temperature effects and fuselage flexibility effects constitutes an important part of the present paper" (p. 1).

Report presenting a visualization study using smoke to see the secondary-flow phenomena in the rotor-blade tip region of a low-speed turbine. Measurements of the factors affecting the flow patterns were recorded from visual observations. Results regarding a general description of the smoke patterns, shroud boundary-layer considerations, transition rotor tip speed, and high-speed-turbine operating conditions are provided.

Note presenting the problem of the effect of yaw on the turbulent boundary layer and skin friction of infinite cylinders, which is reviewed and compared with the case of laminar flow. The conclusion indicates that present understanding of the mechanism of turbulent shear does not permit exhaustion of two-dimensional data even to this elementary case of three-dimensional flow. Results regarding pressure distributions, two-dimensionality and flow direction, velocity profiles, virtual origin, virtual origin for yawed plates, boundary-layer growth, and the results obtained by Young and Booth are provided.

Report presenting an investigation of the effects of many of the parameters significant to wing flutter on several untwisted rotating models to determine their significance with respect to stall flutter of propeller blades. The parameters included torsional stiffness, section thickness ratio, sweepback, length-chord ratio, section center-of-gravity location, blade taper, Mach number, and fluid density. Results regarding the considerations on method of presentation, experimental data and discussion, some possible applications, and a comparison of experiment with classical-flutter theory are provided.

Technical note presenting tests conducted to determine the factors influencing the thermal conductance across the interface formed between stationary plane surfaces of 75S-T6 aluminum-alloy and AISI Type 416 stainless-steel blocks. The types of joints investigated included bare metal-to-metal contact, contact surfaces separated by a good conductor (brass), and contact surfaces separated by a thin sheet of insulation (asbestos). Results regarding the effect of surface roughness, pressure, mean interface temperature, temperature drop, sandwich material, time as a factor in conductance, and effect of test reassembly and interface matching are provided.

Report presenting an investigation in the free-flight tunnel to determine the static stability characteristics of several fuselages with a relatively flat cross section and a high fineness ratio. Results regarding the fuselages alone and fuselages with various vertical and horizontal surfaces are provided.

From Introduction: "This report presents a computational procedure which provides for the rapid and accurate calculation of any streamline in a series of special flows. Detailed information is given on the boundary conditions and equations used for computing the characteristic nets and stream function."

From Summary: "The action of halogenated agents in preventing flame propagation in fuel-air mixtures in laboratory tests is discussed in terms of a possible chemical mechanism. The mechanism chosen is that of chain-breaking reactions between agent and active particles (hydrogen and oxygen atoms and hydroxyl radicsls). Data from the literature on the flammability peaks of n-heptane agent-air mixtures are treated. Ratings of agent effectiveness in terms of the fuel equivalent of the agent, based on both fuel and agent concentrations at the peak, are proposed as preferable to ratings in terms of agent concentration alone."

From Summary: "General quenching-distance equations were derived as extensions of the original simple theory of quenching by diffusion of active particles. These equations take into account the possibility of gas-phase chain breaking and branching and the effect of the efficiency of the walls to destroy active particles. The general characteristics of the equations were examined."

"This report presents results of a research and engineering program performed during the first half of 1950 that resulted in an acoustical treatment for the 8- by 6-foot supersonic wind tunnel at the Lewis Flight Propulsion Laboratory" (p. 1).

Report presenting calculations of the lateral response to representative time histories of atmospheric turbulence for two airplanes with widely different dynamic properties and explanations for their differences in behavior. The results indicate that atmospheric turbulence can cause and maintain a lateral hunting oscillation of a plane, which can be fairly regular and more pronounced for lightly damped airplanes. This may explain some of the cases of airplane snaking that have not been explained by other causes.

Note presenting wind-tunnel tests to ascertain the total-pressure recovery of a circular nose inlet utilizing various shapes of inlet lips. The tests were conducted at a free-stream Mach number of 0.237 with inlet flows ranging from low values to choking and at angles of attack from 0 to 25 degrees.

Report presenting an investigation to develop screech instrumentation and to study the mechanism of screech in a 6-inch-diameter simulated afterburner. Probe microphones have been developed to measure frequency, relative amplitude, and relative phasing of the pressure oscillations at positions in a screeching combustor.

Report presenting a free-flight test technique that can be used to obtain damping in roll of sting-mounted wings and wing-fuselage combinations over high subsonic, transonic, and supersonic speeds with rocket-propelled test vehicles. Results regarding delta wings and unswept tapered wings are provided.

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 turbulent-heat-transfer measurements obtained through the use of an axially symmetric annular nozzle consisting of an inner shaped center body and an outer cylindrical sleeve. Results regarding the wall temperatures, variation of local Nusselt number with Reynolds number, density, velocity, and local temperature-recovery factor are provided.

Report presenting turbulent-heat-transfer measurements obtained through the use of an axially symmetric annular nozzle consisting of an inner, shaped center body and an outer cylindrical sleeve for a Mach number of 1.62. Results regarding wall temperatures, variation of local Nusselt number with local Reynolds number, density, viscosity, and variation of local temperature-recovery factor with local Reynolds number are provided.

Report presenting turbulent-heat-transfer measurements obtained through the use of an axially symmetric annual nozzle consisting of an inner shaped center body and an outer cylindrical sleeve at Mach number 2.06. Results regarding the variation of wall temperature with longitudinal distance, variation of local Nusselt number with local Reynolds number, and variation of local temperature-recovery factor with local Reynolds number are provided.

Report presenting surface temperature distributions on a hollow cylinder aligned with the airstream was studied in a Mach 3.12 wind tunnel at a range of Reynolds numbers. Transition with and without single roughness elements was observed from surface temperature distributions and high-speed schileren motion pictures. Results regarding pressure distributions, recovery-factor distributions, high-speed schileren motion pictures, transition Reynolds number, heat-conduction effects, and a qualitative description of observed flows are provided.

Report presenting testing of several configurations of rotor blades in order to evaluate the effect of variations in the blade-pitch-control stiffness and forward speed on the flutter speed.

Report presenting the slender-body approximation of linearized compressible flow as applied to the problem of a delta wing in which flow separation occurs at the leading edges. Leading-edge separation was found to produce an increase in lift over that given by the Jones slender-wing theory and that lift does not linearly increase with angle of attack.

From Summary: "Trajectories of water droplets about an ellipsoid of revolution with a fineness ratio of 10 (10 percent thick) in flight through a droplet field were computed with the aid of a differential analyzer. Analyses of these trajectories indicate that the local concentration of liquid water at various points about an ellipsoid varies considerably and under some conditions may be several times the free-stream concentration. Curves of the local concentration factor as a function of spatial position were obtained and are presented in terms of dimensionless parameters that describe flight and atmospheric conditions."

From Summary: "The trajectories of water droplets in the air flowing past an NACA 6511004 airfoil at a n angle of attack of 0 deg were determined. The amount of water in droplet form impinging on the airfoil, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface were calculated from the trajectories and presented t o cover a large range of flight and atmospheric conditions. These impingement characteristics are compared briefly with those previously reported for the same airfoil at angles of attack of 4 deg and 8 deg."

From Introduction: "The present paper considers the problem of finding the stresses in the plastic range around a circular hole in an infinite plate subjected to uniaxial tension at infinity (fig.1)."