Memorandum presenting the application of the nuclear-reactor simulator to an investigation of the validity of the customary assumption of uniform distributions of fuel burnup and fission-product poisoning in a reactor core. The two-group calculation results show the effects of the approximation on the reactivity, power distribution, and xenon-135 distribution for a specific power reactor in which the initial power density varied by a factor of approximately 4 over the core volume.

"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).

Memorandum presenting an investigation of 4811C ceramic blades and the problems involved in the adaption of ceramic materials to stressed turbine components. Results regarding spin tests and rotating heat-shock runs are provided.

Report presenting the drag-reducing effectiveness of bleeding air to the base region of blunt-base bodies in a supersonic stream was investigated at a Mach number of 1.91.

Memorandum presenting an investigation to determine the effect of mass distribution on the dynamic lateral stability and control characteristics of a model with a 60 degree triangular wing in the free-flight tunnel. Flight tests and calculations were made for five different loading conditions. Results regarding the oscillatory stability, lateral control, and general flight behavior are provided.

"An investigation to determine the structural damping characteristics of a full-scale airplane wing was conducted by the shock-excitation method wherein the wing was loaded to a predetermined deflection and the load suddenly released. The test specimen vibrated at its fundamental bending frequency of 1.69 cycles per second. Only the first 2 or 3 cycles showed any indication of a higher frequency being superimposed upon the fundamental bending frequency" (p. 1).

Report presenting pressure measurements on a semispan model of a cambered and twisted wing, alone and in combination with a fuselage. The wing had 40 degrees of sweepback, an aspect ratio of 10, a taper ratio of 0.4, and 5 degrees of washout at the tip. Results regarding the pressure distribution and flow separation, section characteristics, and span loading characteristics are provided.

Report presenting the rates of flame propagation of four alkylsilanes as determined by the tube method. Results regarding alkylsilane flame velocities, blends of diethylsilane and n-pentane, and flame propagation theories are provided.

Report presenting an investigation to determine the low-speed chordwise pressure distributions near the midspan station of the slotted flap and aileron of a model of the Bell X-1 airplane with a wing of aspect ratio 4, taper ratio 0.5, 0 degree sweepback of the 40-percent-chord line, and a modified NACA 64A004 airfoil section. Results regarding section pressure distribution and section normal-force and pitching-moment coefficients are provided.

An investigation of a method of preparing intricately shaped objects such as turbo-supercharger blades from refractory powders. The method consists of preparing an extremely thick slip of materials like titanium carbide with a small amount of binder, casting the slip in a mold, and freezing to retain the shape of the casting. Results regarding the applicability of the method and factors affecting soundness, are provided.

Report presenting flight testing of a 60 degree delta wing (NACA 65A003 airfoil section) mounted in midwing and high-wing positions on a modified transonic body from Mach numbers 0.8 to 2.0. The high-wing configuration without nacelles had higher drag coefficients than the midwing configuration without nacelles, but both configurations had approximately the same longitudinal distribution and frontal area. Results regarding nacelle internal drag, configuration drag, nacelle drag coefficient, and normal-force coefficient are provided.

Report presenting testing of a ram-jet canard missile model with a wing and horizontal and vertical canard surfaces of delta plan form with 70 degree swept leading edges in the supersonic pressure tunnel. Two ram-jet nacelles were mounted in the vertical plane near the rear of the body and various combinations of components were tested. Results regarding the longitudinal and lateral characteristics, comparison with theory, and effect of nacelles on the model are presented.

Memorandum presenting an investigation made to valuate the effects of vertical height of the horizontal tail on the static longitudinal stability of a model with a wing with 35 degrees of sweepback, an aspect ratio of 4.5, a taper ratio of 0.5, and NACA 64A010 sections. The investigation also included the effects of adding a partial-span, leading-edge chord extension to the outer portions of the wing. Results regarding the effect of tail height, wing-wake and local downwash measurements, and effect of a leading-edge extension are provided.

Memorandum presenting an investigation made of the effects of circular end plates on the aerodynamic characteristics of a modified triangular wing of aspect ratio 2 and taper ratio 0.33. The experimental results show that the addition of end plates produces so slight a difference in the total change in static longitudinal stability with Mach number in the range from 0.6 to 1.9 that no beneficial effects on the trim drag may be realized.

Heat-transfer investigation conducted on cooled as well heated impulse-type turbine blades in a static cascade to determine the effect of direction of heat flow on convective heat-transfer coefficients.

"The steady-state over-all performance characteristics of the J65-B3 turbojet engine were determined in an altitude test chamber for four exhaust-nozzle areas at Reynolds number indices of 0.8, 0.4, and 0.2. This range of Reynolds number indices corresponds to a range of altitudes from about sea level to 51,500 feet at a flight Mach number of 0.8. Generalized data are presented to allow calculation of engine performance at any flight condition corresponding to a Reynolds number index within the range investigated" (p. 1).

A Japanese log rodmeter of the rotating-vane impeller type, with a commutator on the impeller shaft, was calibrated in Langley tank no. 1. The rotational speed of two impellers was determined for forward speeds up to 24 knots at angles of yaw up to ?10 0 . In general, the rotational speeds of two apparently identical impellers tested in the rodmeter decreased with increasing yaw angle, right yaw causing a greater decrease than left yaw. The difference in calibration between the two impellers was approximately the same as that produced by a change in yaw angle from 50 left to 50 right. Evidence of cavitation within the impeller fairing appeared at speeds above 24 knots.