From Introduction: "The purpose of the present paper is twofold. First, a close connection will be established between reverse-flow theorems in subsonic and supersonic, steady-state wing theory and known reciprocity relations between two solutions of the equation the flow field."

Memorandum presenting a theoretical analysis of the supersonic flow about two-dimensional and three-dimensional axially symmetric models restricted by theoretical walls capable of removing the nose shock. Results regarding the supersonic-tunnel interference due to nonreflecting walls and supersonic-tunnel interference due to porous walls are provided.

Memorandum presenting a study of the performance of swirl-can combustor elements for an experimental short-length turbojet combustor utilizing hydrogen fuel at high-altitude operating conditions. Fuel was injected into each element through a tangential, sonic orifice that created a swirling fuel-air mixture within each element. Results regarding combustor blowout, combustion efficiency, outlet temperature distribution, and preliminary performance of multielement combustor are provided.

"Some aileron load characteristics for three thin wings varying in sweep have been presented for Mach numbers from 0.80 to 1.05. For the transonic Mach number range, shock effects exert a large influence on the loading, but the exact location of each shock for a specific wing design cannot be cataloged at the present time. It is shown, however, that the aileron loading, although greater in magnitude than at subsonic speeds, nevertheless varies in as uniform a fashion as at subsonic speeds" (p. 1).

Report presenting an investigation to determine the possibility of using simplified procedures for the estimation of control loads at supersonic speeds. The results indicated that relatively simple procedures are possible for the estimation of loadings on flap-type controls at supersonic speeds for cases when no flow separation occurs ahead of the hinge line.

Report presenting a wind-tunnel investigation at subsonic Mach numbers up to 0.9 to measure the root-mean-square variation of the normal forces on 27 NACA airfoil sections. The effects of thickness-chord ratio, camber, location of minimum pressure, and leading-edge radius were investigated.

Report presenting a consideration of the problem of shaping an adjoining fuselage for a given wing and supersonic Mach number so that the combination will have a low wave drag. Only fuselages that can be simulated by singularities distributed along the body axis are studied.

Report presenting a blade-vibration and rotating-stall survey on a modified version of a production turbojet engine with a 13-stage axial-flow compressor with a design pressure ratio of 7 and an air flow of 120 pounds per second. This testing was carried out due to the problems rotating stall can cause with both experimental and production axial-flow compressors. Results regarding the rotating-stall patterns, rotor-blade vibrations, radial and axial strength of rotating stall, and maximum rotating-stall speed are provided.

Memorandum presenting the Bell X-5 research airplane tested at 58.7 degrees sweepback during the program to determine the characteristics of a variable-sweep fighter airplane at transonic speeds. This paper includes the stability and control characteristics in the stable lift range up to Mach numbers near 1.0 at an altitude of 40,000 feet and to slightly lower Mach numbers at altitudes of 25,000 feet and 15,000 feet. Results regarding general comments, static stability and control characteristics, and longitudinal dynamic stability are provided.

Report presenting an exploratory investigation of three aluminum disoaps of C(sub 8) acids to determine the gelling properties and stabilizing ability in slurries of 50 percent magnesium power and JP-4 fuel. All of the soaps were found to gel the slurries satisfactorily and to exhibit adequate reproducibility of gel properties. Results regarding the soap behaviors, effects of temperature, viscosity, and formation of the gel structures are provided.

Memorandum presenting pulse techniques applied to strain gages for increasing the output level and extending the usable range. Bonded and unbonded strain gages which normally operate with exciting potentials between 3.5 and 14 volts operated satisfactorily with 200-volt pulses of 1-microsecond duration and a repetition rate of 350 per second. Results regarding maximum allowable voltages, effective pulse duration, sensitivity, minimum readable signal, effects of cable capacitance and inductance, sensitivity to external noise, and linearity are provided.

One of the problems connected with the sweptback wing is the difficulty of controlling the location of the center of pressure and hence the pitching moment. A method is presented for designing a wing to be self-trimming at a given set of flight conditions. Concurrently, the spanwise distribution of load on the wing is made to be approximately elliptical, in an effort to maintain low wing drag.

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.

Effective flame speeds of free turbulent flames were measured by photographic, ionization-gap, and photomultiplier-tube methods, and were found to have a statistical distribution attributed to the nature of the turbulent field. The effective turbulent flame speeds for the free flame were less than those previously measured for flames stabilized on nozzle burners, Bunsen burners, and bluff bodies. The statistical spread of the effective turbulent flame speeds was markedly wider in the lean and rich fuel-air-ratio regions, which might be attributed to the greater sensitivity of laminar flame speed to flame temperature in those regions. Values calculated from the turbulent free-flame-speed analysis proposed by Tucker apparently form upper limits for the statistical spread of free-flame-speed data. Hot-wire anemometer measurements of the longitudinal velocity fluctuation intensity and longitudinal correlation coefficient were made and were employed in the comparison of data and in the theoretical calculation of turbulent flame speed.

"The effects of interaction between a landing gear and a flexible airplane structure on the behavior of the landing gear and the loads in the structure have been studied by treating the equations of motion of the airplane and the landing gear as a coupled system. The landing gear is considered to have nonlinear characteristics typical of conventional gears, namely, velocity-squared damping, polytropic air-compression springing, and exponential tire force-deflection characteristics. For the case where only two modes of the structure are considered, an equivalent three-mass system is derived for representing the airplane and landing-gear combination, which may be used to simulate the effects of structural flexibility in jig drop tests of landing gears" (p. 619).

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 general matrix method is developed for the solution of characteristic-value problems of the type arising in many physical applications. The scheme employed is essentially that of Gauss and Seidel with appropriate modifications needed to make it applicable to characteristic-value problems. An iterative procedure produces a sequence of estimates to the answer; and extrapolation techniques, based upon previous behavior of iterants, are utilized in speeding convergence. Theoretically sound limits are placed on the magnitude of the extrapolation that may be tolerated" (p. 747).

Memorandum presenting a turbojet engine with a two-stage turbine operated with pentaborane fuel continuously for 11.5 minutes at a simulated altitude of 55,000 feet at a flight Mach number of 0.8. The engine incorporated an NACA combustor designed specifically for use with pentaborane fuel. Results regarding oxide formation and deposition, engine operating point, effect of oxide deposits on component performance, effect of oxide deposition on overall performance, and some operational comments are provided.

Memorandum presenting results of a supersonic flutter investigation of three low-aspect-ratio control surfaces. Two controls were all-movable but the third had a fixed cutout. Results regarding the experiments and calculations are provided.

Memorandum presenting force-oscillation tests made in the 8-foot transonic pressure tunnel to investigate some effects of an overhang-type aerodynamic balance and of a flow spoiler on the dynamic hinge-moment characteristics of a full-span flap-type rudder on a 5-percent-thick, swept vertical fin of low aspect ratio. Test results how that the aerodynamic damping moment on the plain rudder becomes unstable near a Mach number of 0.975 and remains unstable to the maximum speed of the tests.

Report presenting performance of a two-dimensional external-compression inlet designed for various methods of inlet-engine matching up to Mach 3 at Mach 1.89 and Mach 0. Results regarding shock geometry, two-shock ramps, isentropic ramps, profiles, and cowl drag for the various Mach number tests are provided.

Memorandum presenting an investigation of the performance of inlet configurations with a forebody designed for isentropic external compression at a nominal Mach number of 5.6. At zero angle of attack, all the configurations yielded larger total-pressure recoveries than had previously been obtained with a single-conical-shock inlet. Results regarding the flow about the forebody, inlet performance, and performance comparisons are provided.

Memorandum presenting an investigation of hemispherical nose shapes of titanium, stainless steel coated with aluminum oxide, and uncoated stainless steel with lithium hydride and magnesium as internal coolants. Results regarding titanium models, stainless-steel models (uncoated), stainless-steel models coated with aluminum oxide, solution effects on the decomposition temperature of lithium hydride, effect of lithium hydride and magnesium on temperature measurements, and efficiency of models cooled with lithium hydride are provided.

Transonic flutter derivatives for unswept wing control surface configurations determined by pressure cell measurements. The control surfaces were mounted on a wing with an aspect ratio of 3, a taper ratio of 0.6, and a wing-thickness ratio of 0.06. Results regarding aerodynamic balance, vortex generators, splitter-plate configurations, and wedges are provided.