Report presenting calculations based on dynamometer test-stand data on an 18-cylinder radial engine made to determine the improvement in fuel consumption that can be obtained by gearing an exhaust-gas turbine to the engine crankshaft in order to increase the engine shaft work.

Report presenting tunnel-wall corrections for an airfoil of finite thickness and camber in a two-dimensional-flow wind tunnel. The theory takes account of the effects of the wake of the airfoil and of the compressibility of the fluid and is based on the assumption that the chord of the airfoil is small in comparison with the height of the tunnel. The theoretical results are compared with the small amount of low-speed experimental data available and agreement is seen to be satisfactory, even for relatively large values of the chord-height ratio.

Report discusses the results of testing of flap position and deflection on the aerodynamic characteristics of a NACA 23012 airfoil with a double slotted flap with a chord 30 percent of the airfoil chord. The maximum lift coefficient, profile-drag coefficients, pitching-moment coefficients, lift, and drag are provided at several positions of the flap. The results were also compared to previous testing on several flap configurations.

Report presenting a pressure-distribution investigation conducted in the 4- by 6-foot vertical wind tunnel to determine the air loads on an airfoil with a 22.1-percent-chord balanced split flap. Results regarding section pressure distribution and aerodynamic section coefficients are provided.

Report presenting an investigation of a spoiler-slot aileron on an NACA 23012 airfoil with a full-span 30-percent-chord Fowler flap. The static rolling, yawing, and hinge moments were determined for several angles of attack and flap deflections. The ineffective region could be eliminated by a provision in the aileron linkage that would automatically uprig the ailerons as the flap is deflected.

Report presenting an investigation of several modifications of 20-percent-chord plain and Frise ailerons on an NACA 23012 airfoil in the 7- by 10-foot wind tunnel. Static rolling, yawing, and hinge moments were determined for several angles of attack.

Report presenting lift and elevator hinge-moment characteristics were measured on horizontal tail provided with elevators having three different beveled trailing edges. Results regarding fuselage alone and fuselage interference, lift characteristics of fuselage-tail combination, elevator hinge-moment characteristics, drag, and comparison with data from two-dimensional-flow tests are provided.

Report discusses the results of testing on several models of flying boats, the XPB2M-1, the XPBB-1, the JRM-1, and 11 other models to determine the effect of bow form on the amount of spray thrown onto the windshield of a flying boat in rough water. Several recommendations for reducing the height and volume of spray are provided. Any change in the hull form that softens the impact between the hull and waves seems to reduce the spray.

Report presenting testing of specimens of 17S-T aluminum-alloy fittings with pressed-in steel bushings for various surface conditions. The surface conditions tested included bare surfaces, aonidcal coating and steel cadmium-plate, and one surface treated and the other bare, both without lubrication and with Gredag No. 83 as a lubricant. The calculated coefficients of friction for the various press fits for the investigation ranged from 0.33 for the unlubricated contact of bare steel and aluminum to 0.09 for the specimen with the unlubricated cadmium-plated bushing.

Report presenting an analysis of parallel flow and contraflow single pass heat exchangers, together with charts which allow the direct evaluation of the thermal performance of the units without recourse to trail-and-error techniques. The use of equations and charts is illustrated by several examples.

Report presenting an investigation of the characteristics of air scoops in the NACA propeller-research tunnel. The investigation showed that, at inlet-velocity ratios equal to or greater than 0.3, scoops in a forward position on the fuselage gave total pressures in the inlet nearly equal to free-stream total pressure.

"Equations and necessary data for the calculation of the gaseous radiation from water vapor and carbon dioxide in an exhaust gas heat exchanger are presented. A typical calculation is included" (p. 1).

Report presenting a description of a meter which will measure the heat flowing through surfaces. Its operation is based on the measurement of the temperature decrease through a fixed thermal resistance. Only the case of heat flow independent of time is discussed in this particular report.

Report presenting a method of making strain measurements on a series of circular cylinders with reinforcing rings, subjected to concentrated loads, in which the bending stiffness of the rings was varied systematically over a wide range. Results regarding the general remarks, bending-moment coefficient, and skin shear coefficients are provided.

"Flight tests were made of a type of internally balanced sealed ailerons installed on a Ryan ST airplane. Aileron effectiveness and stick forces were measured at various airspeeds under NACA recording instruments. For comparison, the aileron characteristics were also determined without the internal balance and seals" (p. 1).

"The ends of thin-wall truncated cones of circular section were clamped to rigid bulkheads and the cones subjected to strength tests. The results from torsion tests of five, compression tests of three, and tests in combined transverse shear and bending of 18 truncated cones are given herein. The results of the tests are correlated with the previously published results of corresponding tests of circular cylinders and are presented in charts suitable for use in design" (p. 1).

Report presenting computations made to determine the effect of changes in wing aspect ratio, additional side area, flight-path angle, and normal acceleration on the relation between the fin area and the dihedral angle required for spiral and for oscillatory lateral stability for a hypothetical airplane of the pursuit or fighter categories. The diagrams indicate that the effect of wing aspect ratio on lateral stability is small.

Report presenting the propeller forces due to an angular velocity of pitch, which are analyzed and shown to be very small for the pitching velocities that may actually be realized in maneuvers, with the exception of the spin. A dual-rotating propeller in yaw was found to develop up to one-third more side force than a single-rotating propeller.

From Summary: "Small high-speed single-cylinder compression-ignition engines were tested to determine their performance characteristics under high supercharging. Calculations were made on the energy available in the exhaust gas of the compression-ignition engines. The maximum power at any given maximum cylinder pressure was obtained when the compression pressure was equal to the maximum cylinder pressure. Constant-pressure combustion was found possible at an engine speed of 2200 rpm."

Report presenting an investigation to determine the knock-limited power obtainable by injecting water solutions of monomethylamine and dimethylamine as internal coolants into a CFR engine using AN-F-28, Amendment-2, fuel.

From Introduction: "The purpose of this paper is to show, in a similar manner, the effect of change in the core structure of the tubular intercooler on the over-all dimensions when the operating conditions are fixed."

Report presenting a generalized selection chart for tubular cross-flow intercoolers and another chart for Harrison cross-flow intercoolers. The charts make it easier to select intercoolers for any particular set of design conditions and under limitations on dimensions and pressure drops.

Report presenting tests conducted with a heat-transfer apparatus that simulates the piston-cylinder-wall relation by means of a stationary, electrically heated, smooth-walled aluminum piston and a reciprocating steel sleeve separated by an oil film. Results regarding heat balance, temperature distribution, heat input, speed, average sleeve temperature, side thrust, piston-clearance oil-supply rate, and specific variable correlation are provided.

Report presenting the results of an investigation to determine the fatigue strength of flush-riveted joints manufactured by different riveting methods. Tests were made on a direct stress fatigue machine at room temperature. The results showed that the fatigue strength of the joints was directly affected by the method of riveting used.