Report presenting tests in the two-dimensional low-turbulence pressure tunnel to study the interference effects of various pusher-propeller shaft-housing combinations on a low-drag airfoil. Thirty different combinations were tested, variations being made in shaft size, shape, angle, and fillet.

"In connection with studies of airfoils applicable to large high-speed aircraft, the effects of roughness on three 22-percent-thick airfoils were investigated. The tests were made over a range of Reynolds number from about 6 to 26 x 10(exp 6) for the airfoils smooth and with roughness strips applied to the surfaces. The results indicated that for the roughened models the scale effect was generally favorable" (p. 1).

Report presenting the results of flight investigations showing that a beveled trailing-edge aileron gives as low or a lower profile drag than a contour aileron. Section profile drag and lift coefficients with two different types of ailerons were obtained at 3 different Reynolds numbers.

Three airfoils were tested with an intersecting flat plate normal to the span as a preliminary study of interference effects on airfoils. Small interference effects were noted on the first two airfoils, while larger effects were noted on the NACA 66,2-422 section, which had previously been shown to be unconservative with respect to separation. Airfoils known to be conservative should be used for inboard sections subject to nacelle and fuselage interference.

Report presenting a wooden model equipped with a slotted flap that was tested in the two-dimensional tunnel. It represented a wing section of the Curtiss-Wright P-60A airplane and the NACA 66,2-118 section. Results regarding lift characteristics, drag coefficients, and flap deflection characteristics are provided.

"Pressure-distribution measurements were made at the request of the Materiel Division, U.S. Army Air Corps, on a 24-inch-chord wooden model equipped with a slotted flap and submitted by the Curtiss-Wright Corporation. The tests were made in the Langley two-dimensional tunnel at a Reynolds number of about 5,600,000" (p. 1).

Wing pressure distribution diagrams for several angles of attack and flap deflections of 0 degrees, 20 degrees, and 40 degrees are presented. The normal force coefficients agree with lift coefficients obtained in previous test of the same model, except for the maximum lifts with flap deflection. Pressure distribution measurements were made at Reynolds Number of about 6,000,000.

Report presenting pressure distribution measurements on two 24-inch chord models equipped with Fowler flaps in the two-dimensional low-turbulence pressure tunnel. Results regarding pressure-distribution diagrams and normal-force and moment coefficients are provided.

Report presenting testing in the two-dimensional tunnel of four models submitted by the Glenn L. Martin Company as intermediate sections of the wing of the XB-33 airplane. Each airfoil model had different types of flaps or no flaps at all. Results regarding the lift and drag data, lift coefficients, effect of flap positions, aileron effects, drag coefficients, and hinge-moment coefficients are provided.

Report presenting lift and drag tests made in the two-dimensional tunnel of three airfoil models. The models represented intermediate sections on alternative wings of the XB-32 airplane and were equipped with 0.30 Fowler flaps. Results regarding the Davis model, the C.A.C. model, and low-drag model are provided.

"Tests were conducted in the Langley 24-inch highspeed tunnel to ascertain the static-pressure and total-pressure losses through screens ranging in mesh from 3 to 12 wires per inch and in wire diameter from 0.023 to 0.041 inch. Data were obtained from a Mach number of approximately 0.20 up to the maximum (choking) Mach number obtainable for each screen. The results of this investigation indicate that the pressure losses increase with increasing Mach number until the choking Mach number, which can be computed, is reached" (p. 1).

Report discussing an investigation into the stalling characteristics, aileron effectiveness, and longitudinal stability of a scale model of the XB-36 airplane. The model was tested with the original configuration as well as with several modifications to the outboard panels and flap arrangement.

Report presenting a practical method for determining the chordwise distribution of the rate of heat transfer from the surface of a wing or body of revolution to air. The method is limited to use to the determination of heat transfer fro the forward section of such bodies when the flow is laminar.

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 discussing testing of 2-percent additions of seven aromatic amines on the knock-limited performance of 28-R fuel in a CFR engine. The most effective antiknock additives are described.

Report discussing the results of testing conducted to determine the knock-limited performance of fuel blends containing 80 percent of S-2 reference fuel and 20 percent of several exploratory fuels. Butyl acetate, sec-butyl acetate, isopropyl acetate, sec-butyl alcohol, tert-butyl alcohol, isopropyl alcohol, cyclohexanol, methylcyclohexanol, isobutylcarbinol, sec-butylcarbinol, triethyl borate, and dimethylfuran were examined.

Report discusses the variation of surface-ignition temperature with charge density, fuel-air ratio, and surface-ignition advance. Tests on several fuels were conducted on a supercharged CFR engine to determine surface-ignition temperature as a function of the three variables. It was concluded that surface-ignition temperature is not a satisfactory criterion for differentiating between preignition characteristics of different fuels.

Report discussing the knock-limited performance of blends of triptane and 28-R fuel in an F-4 engine at three sets of conditions and three compression ratios. The knock limits of the triptane blends were more sensitive to compression ratio than the 28-R fuel, and the sensitivities of the blends increased as the severity of other engine conditions increased.

"The knock-limited performance of blends of 0,50; and 100 percent by volume of 2,2,3-trimethylpentane in 28-R fuel determined with a modified F-4 engine at three sets of conditions varying from severe to mild at each of three compression ratios (6.0, 8.0, and 10.0). A comparison of the knock-limited performance of 2,2,3-trimethylpentane with that of triptane (2,2,3-trimethylbutane) is included. The knock-Limited performance of 2,2,3-trimethylpontane was usually more sensitive to either compression ratio or inlet-air temperature than 28-R fuel, but the ratio of the knock-limited indicated mean effective pressure of a given blend containing 2,2,3-trimethypentane and 28-R to the indicated mean effective pressure of 28-R alone was not greatly affected by compression ratio if the engine operating conditions were mild" (p. 1).

Report discussing the knock-limited performance of blends of 2,3-dimethylpentane and 23-R fuel in an F-4 engine at three sets of conditions and three compression ratios. The knock-limited performance of 2,3-dimethylpentane has about the same sensitivity to compression ratio and inlet-air temperature as 28-R fuel.

Report presenting tests to investigate the effect of 2-percent additions of nine aromatic amines on the knock-limited performance of AN-N-28 (28-R) fuel. The results of the testing of antiknock effectivneess of the 27 aromatic amines obtained to date in the program are also summarized.

Report discussing tests on the effect of 2-percent additions of 13 aromatic amines on the knock-limited performance of 28-R fuel in a CFR engine. The amines tested gave good rich mixture response at standard F-4 operating conditions, but were sensitive to engine severity at lean fuel-air ratios.

Report presenting a investigation covering the physical and chemical properties of various ethers as components of aviation fuels. Their antiknock effectiveness and methods of preparation and purification are included. Methyl tert-butyl ether gave the best knock-limited rich mixture response, but isopropyl tert-butyl ether and di-tert-butyl ether gave better results at lean mixtures.

Report presenting the knock-limited performance of nine fuels comprising isolated members of four classes of hydrocarbons in the form of three-dimensional plots of fuel-air ratio, compression temperature, and compression-air density.