Report discussing various features of the stability of ballistic reentry shapes, including considerations for ballistic-missile and manned-satellite reentry capsules. Attainment of satisfactory stability of reentry bodies with subsonic terminal velocities was not found to be too difficult, but undesirable features that may cause marginal stability characteristics may be introduced in an effort to minimize weight. Reentry bodies with supersonic terminal velocities have fewer stability issues.

Report presenting the tracking performance of an automatically controlled interceptor in which the deflection channel incorporated a bank-angle-error computer that commanded rolling velocities of the interceptor proportional to the computed bank-angle errors. Results regarding gravity terms included in bank-angle-error computation and a comparison of modified system using bank-angle-error computer with the prototype system are provided.

From Introduction: "The importance of blunt noses as a means of reducing the heat transfer to high velocity missiles has recently received much publicity. The question of just what blunt shape is best is still moot, and it is the purpose of this paper to present and examine some recent experimental results which may throw some light on this problem."

From Introduction: "Evaluation of tail-pipe burning in this engine with a larger tail-pipe combustion chamber is discussed in reference 1. Results of investigations on tail-pipe burning in this engine at static sea-level conditions are presented in reference 2. An investigation of thrust augmentation by means of injecting water at the inlet of an axial-flow compressor engine is discussed in reference 3."

From Introduction: "Data are presented to show the effects of tail-pipe fuel-air ratio, altitude, and flight Mach number on tail-pipe-burner performance at rated engine speed and approximately constant turbine-outlet temperature. Operational characteristics of the tail-pipe burner and variable-area exhaust nozzle are also reported."

An equation for average heat transfer of a surface was derived when the boundary layer changed from laminar to turbulent. Influences on the heat transfer through a laminar boundary layer of Mach number, temperature ratio (gas temperature divided by wall temperature), and exponents of gas-property temperature relations were shown to be relatively small for air with Mach numbers less than 2 and temperature ratios between 1 and 4. Good agreement was obtained with experimental results from cylinders, an airfoil, and turbine blades.

Report presenting an investigation of a series of flame holders designed with the objective of providing a high combustion efficiency in a ramjet combustor at an inlet air velocity of 200 feet per second, inlet-air pressure of 60 inches of mercury absolute, inlet air temperature of 200 degrees Fahrenheit, and near stoichiometric fuel-air ratio. Results regarding the preliminary experiments, two parallel rows of gutters, three rows of gutters, staggered gutters, simultaneous use of three rows and staggered gutters, use of molybdenum, and magnitude of pressure fluctuations are provided.

"A two-dimensional wedge diffuser, designed to be used with a ducted-airfoil ram jet, was tested on a rocket-powered test vehicle up to a Mach number of 1.45. Orifice plates and a choking section behind the diffuser exit simulated burning in a combustion chamber by providing the proper pressure drop. Results obtained from these tests showed there was no abrupt changes in mass flow and pressure recovery as the model velocity increased through the transonic region" (p. 1).

Performance characteristics of a two-dimensional isentropic diffuser have been experimentally determined at a Mach number of 3.85. At zero angle of attack, a maximum total-pressure recovery of 0.41 was obtained with a supercritical mass-flow ratio of 0.95. As a consequence of the twin-duct arrangement of the diffuser, a large discontinuity in pressure recovery and mass flow with a characteristic hysteresis was encountered between critical and subcritical operation. An asymmetric shock pattern with large-scale separation and flow reversal in one of the passages occurred at reduced mass flows. Pressure and force data presented for an angle-of-attack range from zero to 4 degrees.

Memorandum presenting minimum spark-ignition engines at reduced pressures for ethane, ethylene, acetylene, n-hexane, cyclohexane, and benzene.

Analytical methods are presented for the determination of local values of outside and inside heat-transfer coefficients and effective gas temperatures by use of turbine-blade-temperature measurements. The methods are derived for a number of configurations that can be applied to typical cooled-turbine-blade shapes as well as to other types of heat-transfer apparatus.

From Introduction: "Analyses of heat transfer for liquid metals flowing turbulently in smooth tubes (low Pradtl numbers) are given in reference 1 and 2. The predicted heat-transfer coefficients from these analyses are considerably higher than those determined in the experimental heat-transfer investigations for mercury and lead bismuth given in references 2 to 4. If the analytical and experimental results for flow of gases are compared at low Peclet numbers, they are also found to be in disagreement (references 5 and 6)."

Report presenting a Bendix-Friez Aerovane Anenometer oscillated in the streamwise direction at several frequencies for each of several low wind-tunnel airspeeds. Records of the displacement of the anenometer and velocity indicated by the instrument during oscillation are provided. The over-registration of this anenometer was found to be much smaller than predicted by theory.

This report presents the results of an investigation conducted on the effect of exhaust-stack nozzle area, shape, and length on engine power, jet thrust, and gain in net thrust (engine propeller plus jet). Single-cylinder engine data were obtained using three straight stacks 25, 44, and 108 inches in length; an S-shaped stack, a 90 degree bend, a 180 degree bend, and a short straight stack having a closed branch faired into it. Each stack was fitted with nozzles varying in exit area from 0.91 square inch to the unrestricted area of the stack of 4.20 square inches. The engine was generally operated over a range of engine speeds from 1300 to 2100 r.p.m, inlet-manifold pressures from 22 to 30 inches of mercury absolute, and a fuel-air ratio of 0.08. The loss in engine power, the jet thrust, and the gain in net thrust are correlated in terms of several simple parameters. An example is given for determining the optimum nozzle area and the overall net thrust.

From Summary: "Stability and control characteristics determined from tests in the Langley 19-foot pressure tunnel of a 0.2375-scale model of the Douglas XA-26 airplane are compared with those measured in flight tests of a Douglas A-26 airplane. Agreement regarding static longitudinal stability as indicated by the elevator-fixed neutral points and by the variation of elevator deflection in both straight and turning flight was found to be good except at speeds approaching the stall. At these low speeds the airplane possessed noticeably improved stability, which was attributed to pronounced stalling at the root of the production wing."

"A theoretical study was made of the shimmy of castering wheels. The theory is based on the discovery of a phenomenon called kinematic shimmy. Experimental checks, use being made of a model having low-pressure tires, are reported and the applicability of the results to full scale is discussed. Theoretical methods of estimating the spindle viscous damping and the spindle solid friction necessary to avoid shimmy are given. A new method of avoiding shimmy -- lateral freedom -- is introduced" (p. 147).

From Introduction: "The importance of blunt noses as a means of reducing the heat transfer to high velocity missiles has recently received much publicity. The question of just what blunt shape is best is still moot, and it is the purpose of this paper to present and examine some recent experimental results which may throw some light on the problem."

Report presenting a 45 degree sweptback wing of aspect ratio 3, with twist and a distributed type of camber, tested in combination with a body of fineness ratio 12.5 to determine the lift, drag, and pitching-moment characteristics.

Control requirements were determined from calculated engine performance maps for a fixed-geometry ram jet of a configuration suitable for strategic supersonic missile propulsion. Several control schemes for attaining desired engine performance and for stabilizing missile flight velocity during cruise are presented. The advantages and disadvantages of each system are discussed.

The longitudinal stability and control characteristics of a 1/30-scale model of the Republic XF-103 airplane were investigated in the Langley 8-foot transonic tunnel. The effect of speed brakes located at the end of the fuselage was also investigated. The main part of the investigation was made with internal flow in the model, but some data were obtained with no internal flow. The longitudinal stability and control at transonic-speeds appeared satisfactory. The transonic drag rise was small. The speed brakes had no adverse effects on longitudinal stability.

This report presents the results of an investigation of the hinge moments of ailerons of various chords and spans on two airfoils having the Clark Y and USA-27 wing sections, supplementing the investigations described in NACA-TR-298 and NACA-TR-343, of the rolling and yawing moments due to similar ailerons on these two airfoil sections. The measurements were made at various angles of pitch, but at zero angle of roll and yaw, the wing chord being set at an angle of +4 degrees to the fuselage axis.

"Paper presents a practical method for computing the approximate values of the normal component of the induced velocity at points in the flow field of a lifting rotor. Tables and graphs of the relative magnitudes of the normal component of the induced velocity are given for selected points in the longitudinal plane of symmetry of the rotor and on the lateral rotor axis. A method is also presented for utilizing the tables and graphs to determine the interference induced velocities arising from the second rotor of a tandem or side-by-side-rotor helicopter and the induced flow angle at a horizontal tail plane" (p. 1).