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Report presenting an investigation at subsonic and transonic speeds in the high-speed 7- by 10-foot tunnel to determine the aerodynamic characteristics of a 42.7 degree sweptback wing with a 20-percent-chord and 50-percent-span outboard aileron. The investigation was performed in transonic flow over a bump on the tunnel floor and in subsonic flow on one of the tunnel side walls.

Measured values of lift, drag, and pitching moment at a Mach number of 1.53 and Reynolds numbers of 0.31, 0.62, and 0.84 million are presented for a wing-fuselage combination having a wing leading-edge sweep angle of 63 degrees, an aspect ratio of 3.42, a taper ratio of 0.25, and an NACA 64A006 section in the stream direction. Data are also presented for sweep angles of 57.0 degrees, 60.4 degrees, 67.0 degrees, and 69.9 degrees. The experimentally determined characteristics were less favorable than indicated by the linear theory but the experimental and theoretical trends with sweep were in good agreement. Boundary-layer-flow tests showed that laminar boundary-layer separation was the primary cause of the differences between experiment and theory.

From Introduction: "This report presents the aerodynamic characteristics at low speed end high Reynolds number as determined in the Ames 40- by 80 foot wind tunnel."

This is a report on Analytical Services of the Pile Area Laboratories at Hanford. Pertinent facts are listed regarding the analytical services currently provided by the Analytical Section in the pile areas. The work of the Analytical Section in the pile areas may be classified into five categories as follows: Analysis of pile process water, analysis of power plant (boiler) waters, analysis of drinking water, analysis of columbia (non-process) and Yakima River water, and preparation of reagents and standard solutions.

Note presenting some of the basic general equations governing the three-dimensional compressible flow of gas through a compressor or a turbine in terms of velocity components, total enthalpy, and entropy. The equations are applied to investigate the maximum compatible number of the radial variations of the gas properties between successive blade rows that a designer is free to specify.

"Basic general equations governing the three-dimensional compressible flow of gas through a compressor or turbine are given in terms of total enthalpy, entropy, and velocity components of the gas. Two methods of solution are obtained for the simplified, steady axially symmetric flow; one involves the use of a number of successive planes normal to the axis of the machine and short distances apart, and the other involves only three stations for a stage in which an appropriate radial-flow path is used. Methods of calculation for the limiting cases of zero and infinite blade aspect ratios and an approximate method of calculation for finite blade aspect ratio are also given" (p. 1).

This semiannual report includes references in future items in the Brookhaven National Labratory program as well as an account of progress in the post six months.

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Report presenting a landing investigation with a flying boat with a conventional configuration to determine the applicability of hydrodynamic impact theory in defining full-scale water impact loads. The results indicated that in addition to chine flare and angular rotation, there are many other factors that may affect overall load, such as elasticity effects, sustained pressures on the area behind the chine, and the effect of variation of wing lift during impact.

Report presenting comparisons of the structural efficiency of panels with straight-web and curved-web Y-section stiffeners. In the high-stress region in which failure is at least in part associated with local buckling, panels with curved-web Y-section stiffeners have higher structural efficiencies than panels with straight-web Y-section stiffeners, which is evidenced by higher average stresses at failure, smaller stiffener heights, or wider average spacing of rivet lines.

Field work in White Canyon was initiated to determine reserves of uranium ores and to determine the nature of the physical, geological, and economic conditions affecting mining and milling of such ores.

Report presenting an investigation of the exhaust of corrosive attack in an aluminum alloy wing employing an exhaust-gas-air mixture as a heating medium for ice prevention. There were no cases of structurally serious corrosion on either painted or plain specimens removed from the wing for detailed microscopic and metallurgic examination.

This study was undertaken to determine the maximum temperatures that may be expected in slugs under various operating power levels. Information of this nature is required to properly evaluate the effects on the slug of pile operation at power levels higher than those currently in use.

"Direct-reading design charts are presented for 24S-T aluminum-alloy flat compression panels having longitudinal formed Z-section stiffeners. These charts make possible the direct determination of the stress and all the panel proportions required to carry a given intensity of loading with a given skin thickness and effective length of panel" (p. 1).

"Direct-reading design charts are presented for 24S-T aluminum-alloy flat compression panels having longitudinal straight-web Y-section stiffeners. These charts make possible the direct determination of the stress and all the panel proportions required to carry a given intensity of loading with a given skin thickness and effective length of panel" (p. 1).

"A method developed in a previous report for finding the induced velocity field behind a supersonic wing with known load distribution is used to find the downwash behind a triangular wing with subsonic leading edges. Results are given for the chord plane in the extended vortex wake of the wing and for the vertical plane of symmetry up to about 20 percent of the wing span above the plane of the wing" (p. 1).

Memorandum presenting preliminary tests in order to determine the effect of forced ventilation on the hydrodynamic characteristics of a scale model of a streamline fuselage of a hypothetical transonic airplane. The forced ventilation consisted of air ejected at about 300 feet per second through small orifices distributed over the fuselage bottom in a series of patterns simulating chines or multiple steps. Results regarding resistance, effective hydrodynamic lift, trim, spray, and air flow are provided.

Report presenting an investigation of the take-off and landing behavior in waves of models of a hypothetical flying boat with hull length-beam ratios of 6 and 15. The flying boat had a design gross weight of 75,000 pounds, a wing loading of 41.1 pounds per square foot, and a power loading of 11.5 pounds per brake horsepower for take-off. Results regarding the landing behavior, spray characteristics, and taxiing and take-off behavior are provided.

Note presenting landing tests made with the PB2Y-6 flying boat to determine the effect of production step vents and forebody longitudinal steps on skipping. Skipping was found to occur at higher landing trims without either step vents or longitudinal steps. The steps were found to constitute a powerful method for improving the landing stability.

Report presenting an investigation of the effect of the rate of change of angle of attack on the maximum lift coefficient of a pursuit airplane equipped with a low-drag-type wing in stalls of varying abruptness over a range of Mach and Reynolds numbers. Maximum lift coefficients were found to increase linearly with increasing rate of change of angle of attack per chord length of travel up to the maximum rate attained in the tests.

Note presenting calculations, based on linearized supersonic flow theory and on the additional assumption that the Mach cones yaw with the wing, to determine the effect of thickness on the lateral force and yawing moment of a sideslipping delta wing at supersonic speeds. Generalized equations are derived for delta wings with rhombic profile and constant thickness ratio.

Considerable study has been given to the problem of a cathode-follower coupling circuit for matching a B-wall tube to a properly terminated coaxial cable. A matched circuit makes it possible to obtain faster counting rates independent of practical cable lengths. A breadboard circuit has been built and first results indicate that a two millivolt signal at the input of the cathode-follower will operate the Model 162 Instrument Development Laboratory Scaling Unit when adjusted for maximum gain. This is comparable to the voltage available when the B-wall tube is coupled to its amplifier through a coaxial cable. Shielded room measurements have been completed in the ``R`` Building. One log-amplifier (EL-257) was delivered to group 32, one scaler-multiplier (EL-252) to group 34, one four-input GM mixer (EL-247 to Group 24, and the plating control regulation checker (EL-258) plus the portable pulse generator (EL-261) to Group 12. The scaler-multiplier (EL-253)is 20 per cent complete and the motor-driven slide wire and the four-input gamma mixer (EL-262) are 95 per cent complete. The manufacturing specifications for plating controls and the instruction book for the portable pulse generator (EL-2561) have been submitted for duplication and should be completed by January 31, 1949. The two (2) 6 …

Redox operations and waste metal recovery are reported. Construction in the 100-H, 100-DR, P-10 area pile areas and in the 234-5, 241-BY waste storage, and redox areas, process areas and Richland village are described. Visitor information is given. And construction progress at Schenectady is reported.