Results regarding an investigation to determine the horizontal- and vertical-tail contributions to the static lateral stability of a complete-model swept-wing configuration at high subsonic speeds. Generally, Mach number effects within the range studied and wing effects on the tail contribution were small and the overall trends of the data of the present investigation agreed with those which have been established at low speeds.

"The relation of Whitcomb's "area rule" to the linear formulas for wave drag at lightly supersonic speeds is discussed. By adopting an approximate relation between the source strength and the geometry of a wing-body combination, the wave-drag theory is expressed in terms involving the areas intercepted by oblique planes or Mach planes. The resulting formulas are checked by comparison with the drag measurements obtained in wind-tunnel experiments and in experiments with falling models in free air. Finally, a theory for determining wing-body shapes of minimum drag at supersonic Mach numbers is discussed and some preliminary experiments are reported" (p. 757).

"Theoretical values of performance parameters for liquid ammonia and liquid fluorine as a rocket propellant were calculated on the assumption of equilibrium composition during the expansion process for a wide range of fuel-oxidant and expansion ratios. The parameters included were specific impulse, combustion-chamber temperature, nozzle-exit temperature, equilibrium composition, mean molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, coefficient of viscosity, and coefficient of thermal conductivity" (p. 1).

Report presenting theoretical values of rocket performance parameters for two mixtures of liquid ammonia and hydrazine with flourine as oxidant for a variety of parameters. Parameters included are specific impulse, combustion chamber temperature, nozzle-exit temperature, equilibrium composition, mean molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, coefficient of viscosity, and coefficient of thermal conductivity.

"Theoretical values of performance parameters for liquid ammonia and liquid fluorine as a rocket propellant were calculated on the assumption of equilibrium composition during the expansion process for a wide range of fuel-oxidant and expansion ratios. The parameters included were specific impulse, combustion-chamber temperature, nozzle-exit temperature, equilibrium composition, mean molecular weight, characteristic velocity, coefficient of thrust, ratio of nozzle-exit area to throat area, specific heat at constant pressure, coefficient of viscosity, and coefficient of thermal conductivity" (p. 1).

"An investigation was conducted in the NACA Lewis altitude wind tunnel to improve the altitude performance and operational characteristics of an afterburner primarily by modifying the diffuser-exit velocity profile by changes in diffuser design and by changing the fuel distribution and the flame holder. Twenty configurations, consisting of combinations of six diffuser geometries, six flame-holder types, and twelve fuel systems, were investigated. Data were obtained over a range of afterburner fuel-air ratios at diffuser-inlet total pressures from 2750 to 620 pounds per square foot" (p. 1).

Note presenting a solution to second order in thickness derived for harmonically oscillating two-dimensional airfoils in supersonic flow. For slow oscillations of an arbitrary profile, the result is found as a series including the third power of frequency.

Report presenting a review of available information on the behavior of brittle and ductile materials under conditions of thermal stress and thermal shock. A number of practical methods that have been used to minimize the negative effects of thermal stress and shock are provided.

"An analytical solution has been obtained for the equations of motion of water droplets impinging on a wedge in a two-dimensional supersonic flow field with a shock wave attached to the wedge. The closed-form solution yields analytical expressions for the equation of the droplet trajectory, the local rate of impingement and the impingement velocity at any point on the wedge surface, and the total rate of impingement. The analytical expressions are utilized to determine the impingement on the forward surfaces of diamond airfoils in supersonic flow fields with attached shock waves" (p. 1).

"Afterbody pressure distributions and wave drag were calculated using a second-order theory for a variety of conical boattails at zero angle of attack. Results are presented for Mach numbers from 1.5 to 4.5, area ratios from 0.200 to 0.800, and boattail angle from 3 degrees to 11 degrees. The results indicate that for a given boattail angle, the wave drag decreases with increasing Mach number and area ratio" (p. 1).

Given three presumably identical lots of commercial, sintered, wrought molybdenum, the 1-hour recrystallization temperature of one lot remained above 2900 F by limiting the amount of effective restraining to 35 percent or less. Different recrystallization temperatures were obtained in various atmospheres, the highest in argon and the lowest in hydrogen. Metal thus fabricated and then stress-relieved possessed an ultimate tensile strength at room temperature within 10 percent of metal swaged 99 percent and also possessed equivalent ductility. At 1800 F, equivalent strength and ductility was obtained irrespective of the amount of swaging over the range of 10 to 99 percent.

Note presenting the velocity potentials, span loadings, and corresponding force and moment derivatives for a number of slender-tail arrangements performing a steady rolling motion at supersonic speeds. The method of analysis is based on an application of conformal-transformation techniques.

The preliminary selection of a propeller on the basis of cruising and take-off performance for application to transport airplanes at flight Mach numbers up to 0.8 can be accomplished by the use of charts and methods presented. The charts are of sufficient scope to permit a fairly rapid evaluation of the propeller performance for engine power ratings of 1,000 to 10,000 horsepower. The method is presented primarily in the interest of propeller-noise abatement.

Report presenting working formulas for the steady-state temperatures and thermal stress in heat-generating infinite plates of constant conductivity. Of all planes in the plate, the plate surfaces are always under the greatest tension, and the midplane is under the greatest compression.

Note presenting an investigation of the principal high-speed planing characteristics for a prismatic surface with an angle of dead rise of 0 degrees determined over a wide range of planing variables. Wetted length, resistance, center-of-pressure location, and draft were determined at speed coefficients ranging up to 25.0, beam loadings up to 87.3, and trims up to 30 degrees.

Efficient temperature ranges are indicated for two high-strength aluminum alloys, two titanium alloys, and three steels for some short-time compression-loading applications at elevated temperatures. Only the effects of constant temperatures and short exposure to temperature are considered, and creep is assumed not to be a factor. The structural efficiency analysis is based upon preliminary results of short-time elevated-temperature compressive stress-strain tests of the materials. The analysis covers strength under uniaxial compression, elastic stiffness, column buckling, and the buckling of long plates in compression or in shear.

Report present a study of the problem of determining nonlinear parameters of dynamic systems, such as aircraft or servomechanisms, whose measured responses are nonlinear. Nonconstant coefficients can be determine satisfactorily for first- or second-order systems using one or a combination of the techniques developed. The methods can be divided into three categories: the equations-of-motion methods, the response curve-fitting methods, and the phase-plane methods.

Report presenting experiments conducted to obtain information on heat transfer in turbulent, mixed-free- and -forced-convection flow. The investigation revealed that the total flow regime as characterized by its Reynolds and Grashof numbers can be subdivided into a forced-flow regime, a free-flow regime, and a mixed-free- and -force-convection regime.

"An investigation has been made in the NACA Lewis icing research tunnel to determine the aerodynamic and icing characteristics of a full-scale induction-system air-scoop assembly incorporating a flush alternate inlet. The flush inlet was located immediately downstream of the offset ram inlet and included a 180 deg reversal and a 90 deg elbow in the ducting between inlet and carburetor top deck. The model also had a preheat-air inlet" (p. 1).

Report presenting the results of an investigation of cross-sectional-area distribution, nacelle configuration, and landing-gear-fairing configuration on the minimum drag characteristics of a model of a four-engine bomber airplane with a low-aspect-ratio triangular wing. The lateral stability characteristics are also included.

"An investigation was conducted in the Lewis altitude wind tunnel to evaluate the performance and operational characteristics of the J40-WE-8 afterburner. A brief program of minor modifications to the flame holder, diffuser, and fuel system was undertaken to improve at a burner-inlet pressure level of 620 pounds per square foot. At this pressure level, modifications to the fuel system resulted in an increase in maximum net thrust from 1500 to 1600 pounds and a reduction in specific fuel consumption in the stoichiometric region from 3.70 to 3.15 pounds of fuel per hour per pound of net thrust" (p. 1).

Report presenting the performance of the liquid fluorine-liquid ammonia propellant combination investigated in 100-pound-thrust, water-cooled engines operating at a chamber pressure of 300 pounds per square inch absolute. Several impinging-jet injectors were evaluated in chambers of characteristic length equal to 50 inches. Results regarding specific impulse, characteristic velocity, thrust coefficient, heat rejection, and operational notes are provided.

Report presenting measurements of average heat-transfer and friction coefficients for air flowing through a smooth, electrically heated tube with a bellmouth entrance with a length-to-diameter ratio of 15 and a range of average surface temperatures, Reynolds numbers, exit Mach numbers, and heat fluxes. Results regarding the axial-wall-temperature distribution, heat balance, correlation of heat-transfer coefficients, and correlation of friction coefficient are provided.

Memorandum presenting a summary of the methods for estimation of water landing loads on hydro-ski-equipped aircraft in order to provide a unified picture and bibliography of NACA work on the subject. Two approaches to the problem of calculating hydro-ski landing loads are covered. Results regarding the impact load theory for rigidly mounted hydro-skis, effect of chine immersion on landing loads, impact load theory for shock-mounted hydro-skis, and estimation of the water pressure distribution on impacting hydro-skis are provided.