"A method and equipment are described for determining the surface parameters of contact required for heat transfer calculations. In this method, the output of a surface analyzer for one surface is recorded on one channel of magnetic tape and the output for the other surface of the contact pair on a second channel. The tape is played back to an analog computer which then integrates the analog voltage to compute the void volume thickness, the number of contact points, and the ratio of metallic contact area to the total area."

Abstracts. Results are given for bulk-density and pulse-velocity measurements performed on specimens of the Project Hobo medium. Test techniques, sample handling, and specimen preparation are described. Values are tabulated in terms of sample origin and geological identity.

From Extension of Tables: "Because of its range and size, this table of wavenumbers is in two volumes, Volume I presenting wavenumbers for all wavelengths between 2000 and 7000 A, and Volume II giving wave-numbers for all wavelengths from 7000 A to 10000000 A=1 mm. In some cases Volume I may suffice for ionic spectra, and in others Volume II may be adequate for molecular spectra, but in general both volumes will needed to cover the entire range of spectral wavelengths measured in standard air."

Memorandum presenting an experimental investigation to determine the effect on drag of applying the moment-of-area-rule modifications to wing-body combinations with various wing plan forms. The effect of mounting air-to-air type missiles on the wing-mounted bodies of revolution which are part of the moment-of-area-rule modification was also investigated.

Transonic flutter derivatives for unswept wing control surface configurations determined by pressure cell measurements. The control surfaces were mounted on a wing with an aspect ratio of 3, a taper ratio of 0.6, and a wing-thickness ratio of 0.06. Results regarding aerodynamic balance, vortex generators, splitter-plate configurations, and wedges are provided.

Report presenting a determination of transonic flutter characteristics from pressure cell measurements on control surfaces sinusoidally oscillated at an amplitude of plus or minus 1.08 degrees at frequencies from 5 to 30 cycles per second. Various control-surface configurations were investigated, including internal and external aerodynamic balance, vortex generators, a splitter-plate type of control surface, and superposition of triangular shaped wedges or tetrahedra along the rear portion of the control-surface chord.

Report presenting an investigation in an altitude test chamber using a turbojet engine equipped with an afterburner and ejector to compare directly two techniques of determining thrust that are both applicable to flight installations. One method uses a swinging uncooled rake at the ejector outlet while the other requires extensive instrumentation to measure the momentum forces of systems and the force on the internal surface of the ejector nozzle. Results regarding the swinging-rake technique and internal-pressure technique are provided.

Memorandum presenting results of a supersonic flutter investigation of three low-aspect-ratio control surfaces. Two controls were all-movable but the third had a fixed cutout. Results regarding the experiments and calculations are provided.

Report presenting the results of a supersonic flutter investigation of three low-aspect-ratio control surfaces, two which had all-movable controls and one with a fixed cutout. Experimental results are provided and compared to calculations using the piston theory for plan form 2. Modifications for improving the flutter of the various control surfaces are also described.

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.

Measurement of radioactive carry-over was made on borax III operating at 300 psig and at power levels ranging from 4 to 14 mv. Decontamination factors of from 1.5 x 104 (at 14 mv) were obtained. These data are in essential agreement with those predicted by previous laboratory experimental work.

Two methods for calculating the *reduction in η due to spectral hardening have been used. In the first method it is assumed that the absorption cross section of U-238 is l/v. This indicates no change in η within the error of the calculation. In the second it is assumed that the scattering cross section of uranium is constant. A decrease in η of 3.0% at the centerline of the slug is indicated by this calculation. The assumption U-238 is a l/v absorber is regarded as the most reasonable of the two.

From Summary: "An experimental investigation has been made in the Langley stability tunnel to determine the low-speed yawing, pitching, and static stability characteristics of a 1/10-scale model of the Grumman F9F-9 airplane. Tests were made to determine the effects of duct-entrance-fairing plugs on the static lateral and longitudinal stability characteristics of the complete model in the clean condition. The remaining tests were concerned with determining tail contributions as well as the effect of duct-entrance-fairing plugs, slats, flaps, and landing gear on the yawing and pitching stability derivatives. These data are presented without analysis in order to expedite distribution."

The following document focuses on the study of the absorption spectra of americium chloride. Large samples and a spectrograph of great dispersion were used.

From Introduction: "The Ames Aeronautical Laboratory has in progress an experimental investigation of the aerodynamic characteristics of wings of interest in the design of high-speed fighter aircraft. This program included an investigation in the Ames 6-by 6-foot supersonic wind tunnel at both subsonic and supersonic Mach numbers of a wing-body combination having a 3-percent-thick, unswept, tapered wing with circular-arc sections and an aspect ratio of 3.1 (reference 1).

Report presenting testing of rocket-powered models at supersonic speeds to determine some of the surface conditions on the zero-lift drag of fin-stabilized parabolic bodies of revolution. Two types of models and three types of surface roughness were tested. Results regarding mean-drag coefficients, side-pressure coefficients, and total-drag coefficients are provided.

"A modified triangular wing of aspect ratio 2.53 having an airfoil section 3.7 percent thick at the root and 5.98 percent thick at the tip was designed in an attempt to improve the lift and drag characteristics of triangular wings. Free-flight drag and stability tests were made using rocket-propelled models equipped with the modified wing. The Mach number range of the test was from 0.70 to 1.37" (p. 1).

Report discussing the details of a radiation burst in a spherical reactor using plutonium nitrate fuel that occurred on November 16, 1951 at Hanford Works.

"Investigations have been made in flight and in wind tunnels to determine which components of turbojet installations are most critical in icing conditions, and to evaluate several methods of icing protection. From these studies, the requirements necessary for adequate icing protection and the consequent penalties on engine performance can be estimated. Because investigations have indicated that the compressor-inlet screen constitutes the greatest icing hazard and is difficult to protect, complete removal or retraction of the screen upon encountering an icing condition is recommended" (p. 1).

Report presenting a preliminary analytical evaluation of the air and fuel specific-impulse characteristics of magnesium and magnesium-octene-1 slurries. Adiabatic combustion flame temperature, air specific impulse, and fuel-weight specific impulse are given for each fuel.

From Introduction: "An investigation of the high-speed aerodynamic characteristics of a modified delta wing in combination with a fuselage was conducted in the Langley high-speed 7- by 10-foot tunnel. The model was tested on the sting support system through a Mach number range of 0.40 to 0.90 with both free and fixed transition. Because of the nature of the transition effect, the results seemed to be of the general interest and are presented in the present paper."

"An investigation of a 1/24-scale dynamically similar model of the Boeing B-47 airplane was made to determine the ditching characteristics and proper ditching technique for the airplane. Various conditions of damage, landing attitude, flap setting, and speed were investigated. The behavior of the model was determined from visual observations, motion-picture records, and time-history deceleration records. The results of the investigation are presented in table form, photographs, and curves" (p. 1).

Report discussing an investigation of the rolling effectiveness at transonic and supersonic speeds on a 38.1 degree sweptback tapered wing with NACA 0010-64 airfoil sections and partial-span ailerons of true contour with a modified flt-side blunt trailing-edge shape. The variation of Reynolds number with Mach number and the control effectiveness is provided.

An altitude-wind-tunnel investigation of the performance of AN-F-58 and AN-F-32 fuels in an experimental turbojet engine was conducted over a range of simulated altitudes and flight Mach numbers. Combustion efficiencies obtained with AN-F-58 and AN-F-32 fuels were approximately equal. The minimum-speed altitude operational limit was essentially the same with either AN-F-58 or AN-F-32 fuel. Starting characteristics of the two fuels were approximately the same at low wind milling speeds. Visual observation showed no apparent differences in the carbon-deposition rates of AN-F-58 and AN-F-32 fuels.