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An analytical method of correlating fluid friction data for flow parallel to square array cylindrical tubes in rectangular cross-section flow channels has been devised. In this technique, the experimental values for friction factors and Reynolds moduli are multiplied by correlation terms which yield new friction factors and Reynolds moduli that pertain to the core region of the tube bundle excluding the boundary effects; hence, model configurations with different numbers of tubes and different tube bundle to shell wall spacing can be correlated. Experimental fluid friction data have been obtained on a 25-tube tube bundle by the ARE Division and on a 100-tube tube bundle by the REE Division with some disagreement of results and it was thought that by this technique this disagreement could be explained However, it is shown that for either of these two configurations application of this technique changes the original data by less than five percent and does not bring these data into better agreement. (auth)

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This quarterly report details activities of the Metallurgy Research Sub-Section for the months of January, February, and March of 1956.

Report presents the results of the measurements of intensity of turbulence, the longitudinal and lateral correlation coefficients, and the spectra of turbulence in a 3.5-inch-diameter free jet measured with hot-wire anemometers at exit Mach numbers from 0.2 to 0.7 and Reynolds numbers from 192,000 to 725,000.

Memorandum presenting an analysis comparing engine performance determined by use of a method involving adjustment of engine cycle calculations using JP-4 fuel with performance obtained using hydrogen as a fuel.

Report discussing an investigation to determine the low-speed aerodynamic characteristics of a North American FJ-3 airplane with a segmented spoiler-slot-deflector lateral control system installed ahead of convention ailerons and operated as individual units and as combined segments. The longitudinal characteristics of the plane, the spoiler-slot-deflector effectiveness, and spoiler-deflector hinge-moment data are all described.

Memorandum presenting the results of an experimental investigation to determine the pressure-distribution characteristics of a conically cambered wing with and without pylon-mounted engine nacelles for Mach numbers of 1.6 and 1.9. The pressure data obtained during this investigation indicate that the low-pressure region existing on the upper surface over the forward part of the wing was spread over a larger proportion of the local chord than would be the case for an uncambered wing.

Note presenting an investigation to determine the effects of homogenization treatments and of composition on the tensile properties of as-cast alloys in the Ni(sub 3)Al-intermetallic-phase region. Results regarding the effects of the casting method, hot-workability of stoichiometric Ni(sub 3)Al, mechanical properties, and microstructure of Ni(sub 3)Al are provided.

Report presenting the steady-state diffusion and transport theory solutions of several self-shielding problems for multiregion cells of rectangular and cylindrical geometries. Results regarding the rectangular case and cylindrical case are provided.

Report presenting a calculation procedure by which the dimensions of the core of a gas-to-gas crossflow heat exchanger with prescribed heat-transfer surface can be determined rapidly. The procedure is based on a number of charts that may be prepared for each surface with prescribed entrance conditions, pressure drops, and temperature changes.

Report presenting an experimental investigation to determine the effects of various geometric and flow factors on the discharge coefficients for circular holes with flow parallel to the plane of the hole. The geometric and flow factors considered were hole diameter, wall thickness at the hole, parallel-flow duct height, boundary-layer thickness, parallel-flow velocity, static-pressure level, and pressure ratio across the test hole.

Report presenting pressure distributions calculated for some symmetrical wing-body combinations at zero lift. Of particular interest is the effect of indenting the body on the distribution of pressure over the wing.

Report presenting an investigation of a body-contouring method for alleviating adverse interference of a high-aspect-ratio sweptback wing at high speeds. Modifying the body shape did not significantly affect the aerodynamic characteristics at subcritical speeds, but beneficial results were obtained at free-stream Mach numbers above critical. Results regarding force and pressure studies are provided.

Report presenting a series method of determining two-dimensional vortex paths is considered and applied to the computation of vortex positions behind a slender equal-span cruciform wing at any angle of bank as a function of the distance behind the trailing edge.

Report presenting an investigation of the rotating stall characteristics of several guide-vane-rotor and guide-vane-rotor-stator configurations. Guide vanes of 4 different turning angles were tested. Results regarding initial rotating stall point, number of stall zones formed, surge, flow fluctuations due to rotating stall, pressure fluctuations due to rotating stall, and stall propagation rate are provided.

Report presenting results of an exploratory free-flight investigation at zero lift of several rocket-powered drag-research models with 60 degree sweptback delta wings presented for a range of Mach numbers. The airfoil sections tested included the NACA 65-006 and a series of double-wedge sections with various thicknesses and positions of maximum thickness.

Report presenting an investigation in the 7- by 10-foot tunnel to determine the feasibility of using a serovane control at high-subsonic and low-transonic speeds. The control could presumedly be deflected with relatively low control forces compared to flap-type controls. Through the range tested, the servovane control produced increments of lift, pitching moment, and rolling moment int he correct direction over most of the angle-of-attack range tested.

From Introduction: "The time-averaged flows are considerably simpler to deal with theoretically than are the instantaneous flows, and the results of several theoretical analyses are available (refs. 2 to 6, for example). Several previous experimental investigations (see ref. 7 for a bibliography) have provided some qualitative information on the subject by the use of smoke in flight and in wind tunnels. However, quantitative measurements (refs. 8 to 10) are extremely scarce and, in general, are inadequate either to define the nature of the flow or to check the accuracy of the theoretical calculations."

Report presenting measurements of the resistance to air flow of a series of perforated metal sheets with open areas ranging from less than 1 percent up to 41 percent. The results showed that the permeability of a perforated sheet is governed principally by its open-area ratio.

Note presenting an axial-flow turbojet engine equipped with a hemispherical target thrust reverser that was pylon-mounted beneath the wing of a cargo airplane. Results regarding the performance of full-depth hemisphere, operational problems, and performance of modified hemisphere are provided.

Note presenting measurements made of the resistance to air flow of a series of perforated metal sheets with open areas ranging from less than 1 percent up to 41 percent. The results showed that the permeability of a perforated sheet is governed principally by its open-area ratio. The number of holes per square inch, the sheet thickness, and the shape of the individual holes had little or no effect on permeability.

From Summary: "Tests of two wing-body combinations have been conducted in the Langley 19-foot pressure tunnel at a Reynolds number of 4 x 10(exp 6) and a Mach number of 0.19 to determine the effects of the bodies on the wing span load distributions. The wings had 45 degrees sweepback of the quarter-chord line, aspect ratio 8.02, taper ratio 0.45, and incorporated 12-percent-thick airfoil sections streamwise. One wing was untwisted and uncambered whereas the second wing incorporated both twist and camber. Identical bodies of revolution, of 10:1 fineness ratio, having diameter-to-span ratios of 0.10, were mounted in mid-high-wing arrangements."