From Introduction: "This paper, which should be of interest to those concerned with transonic wind tunnels, covers the design and operating characteristics of the nozzle."

Report discussing an investigation into the ability of human pilots to control short-period yawing oscillations using a yaw simulating device. The ability to control the oscillations was determined to be a function of period, control effectiveness, and inherent damping. Pilot control effectiveness was found to improve with practice.

Report discussing about 400 references pertaining to the hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings.

Report presenting a study of the acceleration characteristics of a turbojet engine equipped with variable-position inlet guide vanes in the altitude test chamber. Maximum acceleration values for 3 engines of the same model were also obtained during testing and were found to differ as much as 50 percent. Results regarding the effect of fuel step size and inlet guide vane on acceleration, effect of flight condition, reproducibility of engine acceleration, compressor pressure ratio in relation to acceleration, and acceleration with inlet air distortion are provided.

From Summary: "Qualitative investigations have shown that use of the NACA injection impeller with the R-3350 engine increases the inertia of the fuel-injection system and, when the standard fuel-metering system is used, this increase in inertia results in poor engine acceleration characteristics. This investigation was therefore undertaken to determine whether satisfactory acceleration characteristics of the engine equipped with the injection impeller could be obtained by simple modifications to the fuel-monitoring system. The engine was operated with two types of carburetor; namely, a hydraulic-metering carburetor incorporating a vacuum-operated accelerating pump and a direct-metering carburetor having a throttle-actuated accelerating pump."

From Summary: "Tests of a 1/7 size model of the Grumman XJR2F-1 amphibian were made in Langley tank no.1 to examine the landing behavior in rough water and to measure the normal and angular accelerations experienced by the model during these landings. All landings were made normal to the direction of wave advance, a condition assumed to produce the greatest accelerations. Wave heights of 4.4 and 8.0 inches (2.5 and 4.7 ft, full size) were used in the tests and the wave lengths were varied between 10 and 50 feet (70 and 350 ft, full size)."

A 1/5.5-size powered dynamic model of the Columbia XJL-1 amphibian was landed in Langley tank no. 1 in smooth water and in oncoming waves of heights from 2.1 feet to 6.4 feet (full-size) and lengths from 50 feet to 264 feet (full-size). The motions and the vertical accelerations of the model were continuously recorded. The greatest vertical acceleration measured during the smooth-water landings was 3.1g.

From Summary: "An analytical investigation was made to determine from component performance characteristics the effect of air bleed at the compressor outlet on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Consideration of several operating lines on the compressor performance map with two turbine-inlet temperatures showed that for a minimum acceleration time the turbine-inlet temperature should be the maximum allowable, and the operating line on the compressor map should be as close to the surge region as possible throughout the speed range. Operation along such a line would require a continuously varying bleed area."

Report presenting an analytical investigation to determine the effect of compressor interstage air bleed with the use of constant-area bleed ports on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Constant-area interstage bleed, properly located, gave smaller acceleration times than variable-area compressor exit bleed. Results regarding acceleration with interstage bleed, acceleration using constant-area interstage bleed in combination with compressor outlet bleed, variable-area interstage bleed, and comparison of acceleration modes are provided.

From Summary: "An analytical investigation was made to determine from component performance the effect of turbine stator adjustment on the acceleration characteristics of a typical high-pressure-ratio single-spool turbojet engine. Turbine stator adjustment was adequate to permit engine operation in the intermediate-speed range, but was less satisfactory than the relatively simple schemes of compressor-interstage and -outlet bleed."

Memorandum presenting a study of an acceleration-limiting control on a turbojet engine in order to determine its feasibility as an acceleration control. A proportional-plus-integral type of controller was used in the investigation. Results regarding the one-loop control and two-loop control are provided.

Memorandum presenting an acceleration-limiting control used on a turbojet engine to study the feasibility of its use as an acceleration control. A proportional-plus-integral type of controller was used in this investigation. Results regarding one-loop control and two-loop control are provided.

From Introduction: "This report describes some measurements of these quantities obtained by crashing fighter aircraft under circumstances approximating those observed in service."

An equation for quenching distance based on the destruction of chain carriers by the surface is derived. The equation expresses the quenching distance in terms of the diffusion coefficients and partial pressures of the chain carriers and gas phase molecules, the efficiency of the surface as a chain breaker, the total pressure of the mixture, and a constant which depends on the geometry of the quenching surface. Quenching distances measured by flashback for propane-air flames are shown to be consistent with the mechanism. The derived equation is used with the lean inflammability limit and a rate constant calculated from burning velocity data to estimate quenching distances for propane-air (hydrocarbon lean) flames satisfactorily.

"A cascade impactor, an instrument for obtaining the size distribution of droplets borne in a low-velocity air stream, was adapted for flight cloud droplet-size studies. The air containing the droplets was slowed down from flight speed by a diffuser to the inlet-air velocity of the impactor" (p. 1).

The report summarizes source material on combustion for flight-propulsion engineers. First, several chapters review fundamental processes such as fuel-air mixture preparation, gas flow and mixing, flammability and ignition, flame propagation in both homogenous and heterogenous media, flame stabilization, combustion oscillations, and smoke and carbon formation. The practical significance and the relation of these processes to theory are presented. A second series of chapters describes the observed performance and design problems of engine combustors of the principal types. An attempt is made to interpret performance in terms of the fundamental processes and theories previously reviewed. Third, the design of high-speed combustion systems is discussed. Combustor design principles that can be established from basic considerations and from experience with actual combustors are described. Finally, future requirements for aircraft engine combustion systems are examined.

This volume continues the NACA study of combustion principles for aircraft propulsion. The various aspects of combustion pertinent to jet engines are organized and interpreted with quite extensive information, particularly for basic or fundamental. subject matter. The report concerns only air-breathing engines and hydrocarbon fuels, and not rocket engines and high-energy fuels.

"About 500 additional references pertaining to hydrodynamic design of seaplanes have been compiled, and the information is presented in the form of abstracts classified under six main headings:GENERAL INFORMATION, HYDROSTATICS, HYDRODYNAMICS, AERODYNAMICS, OPERATION, and RESEARCH. The compilation is an extension of NACA RM No. L6I13, entitled "Abstracts Pertaining to Seaplanes," by Jerold M. Bidwell and Douglas A. King. An author index and a subject index are included" (p. 1).

From Introduction: "This report makes further comparisons of the theoretical computing method with available experimental results, showing effects of wing plan-form changes, and the effect of an airfoil-section change on a wing of given plan form."

Report presenting an investigation at the Lewis laboratory to develop air-cooled, strut-supported turbine blades. Six blades were investigated in a full-scale turbojet engine to obtain data on blade durability and blade-cooling effectiveness and strut temperature. Results regarding the heat-transfer investigation and blade-durability investigation are provided.

Memorandum presenting an experimental study of the effects of several variations in configuration geometry on the aerodynamic characteristics of flat-top wing-body combinations. Generally, the configurations consist of one half of a body of revolution mounted beneath a wing of essentially arrow plan form. Results regarding the effect of trailing-edge sweep, effect of the addition of auxiliary bodies, effect of tip-flap deflection, effect of dihedral, effect of leading-edge sweep, effect of fuselage fineness ratio, effect of fuselage profile shape, and static longitudinal stability characteristics are provided.

From Introduction: "Reported herein are results of the additional direct-stress fatigue tests on: (1) a plate-type specimen with cored centrally located hole and (2) 0.300-inch-diameter round polished specimens with various degrees of porosity."

From Introduction: "The purpose of the present paper is to present results obtained recently relating to the characteristics of a full-span sharp-edge spoiler with an 0.02-chord projection above the wing surface at several chordwise positions and also to the relative effectiveness of the sharp-edge spoiler and a wedge-type spoiler located at the 80-percent-chord line."

From Introduction: "The results of an investigation of the low-speed static stability of a simplified model of such an arrangement having one of the airfoils placed vertically on top of the body and the other two as wing panels having negative dihedral are presented in reference 1. In order to provide information for predicting the effects of changes in the basic configuration on the low-speed stability characteristics presented in reference 1, additional measurements have been made."