Report presenting a comparison of performance estimates of aircraft nuclear propulsion (ANP) systems and an attempt to determine the manner in which the estimated nuclear propulsion system performance in conjunction with the estimated airframe performance will lead to a useful military airplane.

Report presenting an investigation at two Mach numbers to determine the pressure distributions for a series of 20 controls on a 60 degree delta wing. Thirteen controls were of the balanced tip type and seven of the controls were of the more conventional trailing-edge type. Results regarding the basic pressure distributions, comparison of experimental and theoretical results, and some experimental comparisons are provided.

Report presenting a flight investigation to determine the effectiveness of three fuselage indentations for reducing the pressure drag of a 45 degree sweptback-wing-body configuration at a range of Mach numbers. The results indicate that the supersonic area rule can be used to determine indentations with low pressure drag over a Mach number range in which the blunt leading edge is subsonic. Information about total drag and pressure drag is provided.

Report presenting a low-amplitude free-oscillation investigation at zero angle of attack of the damping in yaw and directional stability of a fuselage-tail configuration through a range of reduced frequency. The damping in yaw was found to decrease with Mach numbers above 0.8 and became the lowest at about 1.0. An increase in reduced frequency was observed to cause a decrease in damping in yaw and directional stability for the test frequency range.

Report presenting the results of an investigation of wing-body juncture interference effects at high subsonic and transonic speeds. Three different model series were used: one with a swept wing of aspect ratio 6 and two with swept wings of aspect ratio 3. Results regarding drag, lift, pressure distributions, and tests with the body alone are provided.

Report presenting studies to determine the effect of sliding velocity and ambient temperature on the friction properties and endurance lift of thin lead monoxide coatings bonded to type 440-C martensitic stainless steel. Results regarding the effect of run-in on endurance life are also provided.

This reports presents the results of measurements made of yawing moments produced by rudder displacement for seven rudders mounted on each of three fuselages at angles of pitch of 0 degree, 8 degrees, 12 degrees, 20 degrees, 30 degrees and 40 degrees. The dimensions of the rudders were selected to cover the range of areas and aspect ratios commonly used, while the ratios of rudder area to fin area and of rudder chord to fin chord were kept approximately constant. An important result of the measurements is to show that increased aspect ratio gives increased yawing moments for a given area, provided the maximum rudder displacement does not exceed 25 degrees. If large rudder displacements are used, the effect of aspect ratio is not so great.

"This report covers the results of an investigation carried on at the Bureau of Standards under a research authorization from, and with the financial assistance of, the National Advisory Committee for Aeronautics. The choice of a damping liquid for aircraft instruments is difficult owing to the range of temperature at which aircraft operate. Temperature changes affect the viscosity tremendously. The investigation was undertaken with the object of finding liquids of various viscosities otherwise suitable which had a minimum change in viscosity with temperature" (p. 405).

For a given wing and supersonic Mach number, the problem of shaping an adjoining fuselage so that the combination will have a low wave drag is considered. Only fuselages that can be simulated by singularities (multipoles) distributed along the body axis are studied. However, the optimum variations of such singularities are completely specified in terms of the given wing geometry. An application is made to an elliptic wing having a biconvex section, a thickness-chord ratio equal to 0.05 at the root, and an aspect ratio equal to 3. A comparison of the theoretical results with a wind-tunnel experiment is also presented.

"A graphical method is described for finding the shape (camber and twist) of an airfoil having an arbitrary distribution of lift. The method consists in replacing the lifting surface and its wake with an equivalent arrangement of vortices and in finding the associated vertical velocities. By division of the vortex pattern into circular strips concentric about the downwash point instead of into the usual rectangular strips, the lifting surface is reduced for each downwash point to an equivalent loaded line for which the induced velocity is readily computed" (p. 543).

An extended form of the Ackeret iteration method, applicable to arbitrary profiles, is utilized to calculate the compressible flow at high subsonic velocities past an elliptic cylinder. The angle of attack to the direction of the undisturbed stream is small and the circulation is fixed by the Kutta condition at the trailing end of the major axis. The expression for the lifting force on the elliptic cylinder is derived and shows a first-step improvement of the Prandtl-Glauert rule. It is further shown that the expression for the lifting force, although derived specifically for an elliptic cylinder, may be extended to arbitrary symmetrical profiles.

Report discussing an investigation on the effect of engine skew on the directional and lateral control characteristics of a single-engine airplane with a single-rotating propeller. The estimated and test results showed an advantage to skewing the propeller, as it assists with overcoming inadequate rudder control in power-on flight and aileron control, especially with flaps deflected.

Report presenting the results of an analytical investigation, which demonstrated that the inlet of a turbojet engine can be protected from ice accretions by bleeding hot gases from other locations within the engine to the inlet without undue loss in thrust. Results regarding the bleedback requirements, engine performance, effect of nozzle area, mixing efficiency, and seriousness of thrust losses are provided.

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.

Report presenting an investigation at Mach numbers of 1.61 and 2.01 to determine the pressure distributions for a series of 20 controls on a 60 degree delta wing. Tests occurred at a range of angles of attack and control deflections. Results regarding basic pressure distributions, comparison of experimental and theoretical results, and experimental comparisons are provided.

Memorandum presenting an investigation of performance estimates of aircraft nuclear propulsion (ANP) systems. This paper includes a relation of current estimated ANP performance to the future requirements that nuclear propulsion systems will be required to meet.