Report discussing testing to determine the drag characteristics at zero lift of a wing with a circular-arc airfoil section with a maximum thickness of 9 percent chord. The results were compared to previous testing on an NACA 65-009 airfoil. It was found that the NACA airfoil had lower drag coefficients than the circular-arc airfoil tested in this experiment.

Experimental data are presented on the variation of the modulus of rigidity in the temperature range -20 to +50 degrees C. of a number of metals which are of possible use for elastic elements for aircraft and other instruments. The methods of the torsional pendulum was used to determine the modulus of rigidity and its temperature coefficient for aluminum, duralumin, monel metal, brass, phosphor bronze, coin silver, nickel silver, three high carbon steels, and three alloy steels. It was observed that tensile stress affected the values of the modulus by amounts of 1 per cent or less.

Report presenting local coefficients of convective heat transfer as measured from skin temperature along the body of an RM-10 NACA research missile, which consisted of a parabolic body of revolution. Results regarding recovery factors, adiabatic wall temperatures, Nusselts, Prandtl, and Reynolds numbers, and boundary-layer transition are provided.

There have been numerous independent suggestions to use high speed shocks to heat deuterium gas to thermonuclear temperature (E. Teller, R.R. Wilson, H. Grad, W. Marshall)², and extensive experimental work in this field is being carried on by, e.g., Kolb³, and S. Janes⁴. Our own work in this field has been directed towards a fundamental understanding of the strong shock process in the limit of no particle collision, to find out if within this limit the ion heating following the passage of the shock is large enough to give rise to a thermonuclear reaction.

Report presenting testing of a 6.5-inch-diameter ramjet engine with a design Mach number of 2.13 and a short-flame-length combustor. Performance characteristics are provided for a range of Mach numbers and fuel-air ratios. Results regarding thrust, drag tests, static pressure, and combustion efficiencies are provided.

Report presenting the effects of a low-speed wind-tunnel investigation to determine the effects of vertical-fin location and area on the static and rotary lateral stability characteristics of semitailless airplane models. Results regarding straight flow, yawing flow, and rolling flow are provided.

From foreword: This report presents the preliminary design of a gamma irradiator intended for use as an experimental hospital sterilizer.

Sodium hydride dissolves in and reacts with molten NaOH to give an equilibrium mixture of NaH, NaOH, Na/sub 2/O, Na, and H. In the case where there is a gaseous phase (hydrogen) and only one condensed phase, the system is defined by the temperature, pressure, and one composition variable. The equilibrium, H/ sub 2/ pressure, which is a measure of the H/sub 2/ activity within the melt, was determined as a function of the composition of the condensed phase(s) at 600, 700, and 500 deg for equilibrium mixtures with original compositions of 2.5 to 97.5, 5.0 to 95.0, l0.0 to 90.0, and 20.0 to 50.0 mole% NaH-NaOH. The equilibrium H/sub 2/ pressure-composition isotherms obtained by removing measured increments of H/sub 2/ were reproduced by reabsorbing H/sub 2/. Results for the 5.0 mole % NaH mixture were duplicated by starting with an equivalent quantity of either Na in NaOH or Na/sub 2/O in NaOH, and reacting with measured increments of H/sub 2/. The system is discussed in relation to the interdependent reactions involved, the phase rule, the thermodynamics of certain reactions, and experimental techniques employed. (auth)

Portions of the NaOH-NaH phase diagram were studied by means of differential thermal analysis. Under certain conditions NaH will either react with NaOH according to the equation NaH + NaOH in equilibrium Na/sub 2/O + H/ sub 2/ or thermally dissociate according to the equation NaH in equilibrium Na + 1/2 H/sub 2/. Both of these reactions are suppressed by a high H/sub 2/ pressure; and NaH neither reacts nor dissociates to an extent sufficient to affect the results reported. This was evidenced by the fact that changing the H/ sub 2/ pressure above the system in the range indicated did not change, within the limit of error of the experiments ( approximately plus or minus 5 deg ), the temperature at which a phase change was started or completed. Therefore the concentrations of Na and Na/sub 2/O present in the samples must have been small in all cases. Under a high H/sub 2/ pressure, therefore, the system may be considered as essentially binary, consisting of NaOH and NaH. (auth)

Considerable interest has been shown at HAPO in the development of a continuous ion exchange process for concentrating plutonium solutions. Development work has been performed on continuous ion exchange for both uranium and plutonium concentrations at the X-10 at ORNL. On a recent trip to Oak Ridge to discuss critical mass problems and experiments with Dr. A. D. Callihan of the ORNL critical mass facility, a meeting was also held with C. W. Hancher and R. Higgins of X-10 regarding continuous ion exchange operation. From this meeting, information was obtained that is helpful to work out nuclear safety aspects of such a plant for the concentration of plutonium solutions. An advance copy of "Countercurrent Ion Exchange" by T. A. Arehart, J. C. Bresee, C. W. Hancher, and S. H. Jury was obtained. This paper is to be presented at an AIChE meeting this fall. Preliminary blue prints of ORNL-3" Ion Exchange column design were also obtained. Upon my return to HAPO, a meeting was held with members of the Process Planning, Equipment Development, and Chemical Engineering Development Units of the Chemical Engineering Sub-Section (Separations Technology) to present the document and blue prints on continuous ion exchange and arrive at a …

The use of ceramic material for rocket nozzles and the effectiveness of preventing oxidation and erosion of graphite nozzles by chrome-plating the internal surface were investigated. A supported ceramic nozzle, cracked by initial operation, was operated a second time without further cracking or damage. Chrome-plating the internal surface of graphite nozzles effectively prevented oxidation and erosion that occurred during operation with unprotected graphite.

From summary: "On the basis of the tests described herein, the corrosion characteristics of T-347 welded stainless steel are found not to be affected by the magnetic properties of the welds even though these properties are likely the result of the presence of the ferritic structure."

The bending stresses in the covers of box beams or wide-flange beams differ appreciably from the stresses predicted by the ordinary bending theory on account of shear deformation of the flanges. The problem of predicting these differences has become known as the shear-lag problem. The first part of this paper deals with methods of shear-lag analysis suitable for practical use. The second part of the paper describes strain-gage tests made by the NACA to verify the theory. Three tests published by other investigators are also analyzed by the proposed method. The third part of the paper gives numerical examples illustrating the methods of analysis. An appendix gives comparisons with other methods, particularly with the method of Ebner and Koller.

From abstract: "On the 86-inch cyclotron a 41-kw beam has been calorimetered at a net ion loading efficiency of 40%; the average proton current was 1.85 ma at 22.5 Mev. Practical specific yields have been determined for (p,2n) reactions on zinc and bismuth. The investigation of products of proton-induced fission of uranium has been continued and new techniques are being used in measuring angular distribution of reaction products. The 63-inch heavy particle cyclotron is now in operation; N+++ particles have been accelerated to ~25 Mev. In preliminary tests, induced activities have been detected in carbon, nitrogen, and oxygen targets. A hot-cathode ion source is ready for test operation. The 22-inch cyclotron is being used in an investigation of the problems associated with the use of rf and dc electrodes for the acceleration of protons from the ion source into the dees. Radiation-induced corrosion in Inconel tubing containing #21 eutectic (ANP) has been produced by proton irradiation in the 86-inch cylclotron; it is shown that the corrosion was not due to thermal effects. Approximately 150 grams of highly purified U 238 (< 5 ppm U 235) have been prepared, and two grams of thorium 230 (ionium) has been enriched to 90.6%."

A report describing the methods and results of a chemical copper determination. A colorimetric method was considered the most feasible. Results and further discussion are provided in the report.

Memorandum presenting a study of the relationship between the static and dynamic properties of heat-resistant alloys at high temperatures. An auxiliary objective is to provide a better basis for evaluating the results from the various types of fatigue machines.

Storage of the fission products separated from the product streams of the Purex process is being accomplished using a smaller volume of accompanying solution than any other process here-to-fore used at HAPO. The operating technique and control mechanisms which are needed to store large quantities of these highly radioactive wastes are not yet fully understood, but considerable insight into the problem has been gained from the experience at Redox during the last 36 months. The basic intentions of the 241-A Storage Facility design is to control the boiling wastes by providing suitable tanks to contain the liquid and a vapor system provided with suitable seals to control the vapors. This document (Part I) will present a somewhat detailed description of the Purex Storage Facility and a review of the activities there before plant start-up. Part II, published under separate cover, contains a description of Waste Farm Technology including a process description and a recommended plan for operation.

Memorandum presenting tests in the 9-inch supersonic tunnel to investigate the factors that determine the magnitude of the wing-tail interference effects on the static longitudinal stability of supersonic missile configurations with low-aspect-ratio, tandem, cruciform lifting surfaces and to develop a missile configuration with a minimum variation in static margin due to wing-tail interference effects.

Memorandum presenting lift, drag, and pitching-moment data and some static rolling-moment data are presented for missile configurations having wing-tail-span ratios equal to and less than 1. The configurations include variations in wing and tail plan forms, wing-tail-span ratios, body length, and nose shape.

Report presenting boundary-layer measurements on rocket-powered free-flight models to determine average skin-friction coefficients. The test body, NACA RM-10, was a fin-stabilized parabolic body of revolution of fineness ratio 12.2 with a blunt base to provide space for a rocket jet. Results regarding the skin-friction and boundary-layer profiles and experimental and theoretical curves are provided.

Report presenting an investigation of the pressure distribution over a leading-edge flap in the 19-foot pressure tunnel. Testing occurred on 42 degree and 52 degree sweptback wings of NACA 64(sub 1)-112 sections, with the 42 degree wing being used in conjunction with a circular cross-section fuselage in a high-wing combination.

Memorandum presenting a single J33 combustor and an experimental tubular combustor incorporating a fuel vaporizer as operated with gaseous hydrogen at temperatures slightly above the boiling point of the fuel. Data were obtained to explore possible effects of the fuel temperature on combustor performance and on the control and measurement of fuel flow.

A 4-ft-7-in. adsorption column packed with 1/8 in. sodium fluoride pellets was designed to reduce the hydrogen fluoride content of the fluorine being used by the Volatility Pilot Plant from 5% to less than 0.01%. It will be a non-isothermal packed bed with the bas inlet heated to 100 C to avoid plugging and the exit cooed to 25 C for more complete HF removal.

This document contains reproductions of technical papers on some of the most recent research results on aircraft structures from the NACA Laboratories. These papers were presented by members of the staff of the NACA Laboratories at the NACA conference held at the Langley Aeronautical Laboratory March 7, 1951. The purpose of this conference was to convey to those involved in the study of aircraft structures these recent research results and to provide those attending an opportunity for discussion of these results.