From Introduction: "The purpose of this report is to present the results of the analysis and to compare them with the experimental results of the transonic turbine."

Memorandum presenting a rocket-propelled model of a representative 35 degree sweptback wing airplane design at high subsonic Mach numbers to investigate the possibility of the existence of coupled longitudinal and lateral motions. The data indicate the existence of sustained longitudinal motions of appreciable amplitude forced by lateral oscillations. The longitudinal motions had twice the frequency of the lateral oscillations and are shown to be the result of aerodynamic moments due to sideslip and inertial cross coupling.

"A considerable weight reduction in the turbine wheel of an aircraft gas turbine is attained through the use of high-aspect-ratio rotor blading. An experimental investigation was made to compare the performance of a turbine of conservative aerodynamic design having shrouded rotor blades with an aspect ratio of 4.48 with that obtained from both a shrouded and an unshrouded rotor design with aspect ratio of 2.24. The use of high-aspect-ratio rotor blades had a negligible effect on the turbine efficiency" (p. 1).

Report presenting an investigation to determine the blade torsional deflection of three supersonic-type propellers at various operating conditions. Blade-torsional deflection was found to produce appreciable results that can be predicted by theory with good accuracy. Results regarding the efficiency, thrust coefficient, and power coefficient are provided.

Abstract: A visualized electron beam has been reflected by a conventional magnetic mirror. Visualization of the beam path from the electron gun to and including the region of reflection was achieved by the "thread ray" technique of Wehnelt. The total current passing through a magnetic mirror has been measured as a function of the beam energy and angular momentum for H₂ over a range of pressures from 0.5 to 5 microns.

Report regarding the mathematical analysis of the exponential pile experiment using highly absorbent slugs and assuming the emitting of fast neutrons. Related theory and equations are discussed.

An investigation was conducted on a 35 deg swept-wing fighter airplane to determine the effects of several blunt-trailing-edge modifications to the wing and tail on the high-speed stability and control characteristics and tracking performance. The results indicated significant improvement in the pitch-up characteristics for the blunt-aileron configuration at Mach numbers around 0.90. As a result of increased effectiveness of the blunt-trailing-edge aileron, the roll-off, customarily experienced with the unmodified airplane in wings-level flight between Mach numbers of about 0.9 and 1.0 was eliminated, The results also indicated that the increased effectiveness of the blunt aileron more than offset the large associated aileron hinge moment, resulting in significant improvement in the rolling performance at Mach numbers between 0.85 and 1.0. It appeared from these results that the tracking performance with the blunt-aileron configuration in the pitch-up and buffeting flight region at high Mach numbers was considerably improved over that of the unmodified airplane; however, the tracking errors of 8 to 15 mils were definitely unsatisfactory. A drag increment of about O.OOl5 due to the blunt ailerons was noted at Mach numbers to about 0.85. The drag increment was 0 at Mach numbers above 0.90.

Results are presented of wind-tunnel investigations at Mach numbers of 0.60 to 0.94 and angles of attack of -2 degrees to about 24 degrees to determine the lateral control characteristics of spoilers with various wing chord-wise and spanwise locations and spoiler spans and deflections on thin 60 degree delta wing of NACA 65a003 airfoil section parallel to free stream.

Memorandum presenting an analysis to determine the compressor pressure ratios and specific weight flows obtainable with single-stage air-cooled turbines for both nonafterburning and afterburning turbojet engines operating at a flight Mach number of 2 in the stratosphere. Wide ranges in turbine-inlet temperature, tip speed, hub-tip radius ratio, and coolant-flow ratio were considered.

Report presenting an investigation of a conservatively designed experimental cold-air turbine with and without a shroud band on the rotor blades. The tip of the rotor blade was oriented toward the tangential direction so that the adverse effect of blade-tip scraping would not be appreciable. The efficiency for the unshrouded-rotor configuration was about one point higher than for the shrouded rotor.

Report presenting an investigation to study the aerodynamic problems associated with a turbine design for a mode of engine operation which utilizes turbine stator adjustment to maintain a fixed compressor operating point. An indication of the turbine requirements for a particular compressor operating point indicated that a feasible sing-stage air-cooled turbine design could be obtained within reasonable aerodynamic limits. Results regarding the performance of the turbine, pressure ratios, and operational requirements are provided.

Report presenting an investigation of combustion oscillations using white fuming nitric acid and a hydrocarbon fuel in a 1000-pound-thrust rocket engine. Results regarding rotary oscillation shown by 40,000-frame-per-second photographs, oscillations recorded by streak photography, ion gap traces, pressure measurements, and plastic chamber erosion are provided.

Economic study covering several classes of cycles of reactor steam power plants.

From Introduction: "This paper presents the results of an investigation conducted in the Langley 11-inch hypersonic tunnel to evaluate methods of increasing maximum lift-drag ratio."

From introduction: "The present paper deals with a classical calculation in which some of the meson effects can be included to all orders in the meson-nucleon coupling coupling constant, in particular those having to do with the gyration of the nucleon spin and isotopic spin. Such a treatment leads to results qualitatively different from the weak coupling calculations."

Report presenting flight measurements of the buffeting characteristics of the Bell X-5 airplane at 58.7 degrees of sweepback at a range of Mach numbers and altitudes. Information about tail buffeting and wing buffeting at several angles of attack is provided. The pilot considered the buffeting to be unobjectionable throughout the entire test region.

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Report discussing the progress made on various research projects at North American Aviation during the quarter from January to March 1954.

Report presenting an investigation in the transonic tunnel to determine the basic aerodynamic and loading characteristics of an unswept-wing-fuselage combination with a wing of aspect ratio 4, taper ratio 0.5, and NACA 65A004 airfoil sections. Force, moment, and pressure measurements were obtained for a range of Mach numbers and angles of attack.

Summary of miscellaneous updates related to the project. This includes information on the following. Simplified equations for modeling reactor conditions. Solubility tests involving thorium, bismuth, and protactinium. various other measurements and tests involving thorium, uranium, protactinium, bismuth, aluminum, and various other salts.

"A series of shock tube studies demonstrate that two types of pressure gauges respond to dust carried with shock waves by indicating an increase in dynamic pressure. This contribution to the dynamic pressure is approximately the product of the dust density and the square of the dust velocity under the experimental conditions. Besides this information studies give insight into the interaction of a square shock wave with dust when that dust is placed in a plane before and parallel to the shock front. It is found that the shape of the pressure wave is little changed except for a rounding of the front. The dust, after accelerating, is carried as a pulse with the mass flow velocity of the air."

The following quarterly report covers the period of January, February and March of 1954, discussing medical and health physics such as: the metabolic properties of various materials, biological studies of radiation effects, lipoprotein studies, health chemistry, and health physics.

A preliminary study has been made of a solid homogeneous reactor for stationary power plant application. The core consists of graphite spheres impregnated with uranium and thorium, and the coolant is bismuth. This concept possible offers advantages over other solid fuel reactor systems with respect to simplification of core structure, fuel fabrication and fuel handling, and reduction of fuel inventory external to the reactor. From the results of this preliminary study, it appears that the potential cost of electric power from this reactor is competitive with that from other reactor systems which have been proposed for the same application. The Po210 produced in the coolant presents a decontamination problem, but is also possibly a valuable by-producgt.

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