Memorandum presenting a theoretical analysis of the supersonic flow about two-dimensional and three-dimensional axially symmetric models restricted by theoretical walls capable of removing the nose shock. Results regarding the supersonic-tunnel interference due to nonreflecting walls and supersonic-tunnel interference due to porous walls are provided.

Memorandum presenting a study of the performance of swirl-can combustor elements for an experimental short-length turbojet combustor utilizing hydrogen fuel at high-altitude operating conditions. Fuel was injected into each element through a tangential, sonic orifice that created a swirling fuel-air mixture within each element. Results regarding combustor blowout, combustion efficiency, outlet temperature distribution, and preliminary performance of multielement combustor are provided.

Memorandum presenting a turbojet engine with a two-stage turbine operated with pentaborane fuel continuously for 11.5 minutes at a simulated altitude of 55,000 feet at a flight Mach number of 0.8. The engine incorporated an NACA combustor designed specifically for use with pentaborane fuel. Results regarding oxide formation and deposition, engine operating point, effect of oxide deposits on component performance, effect of oxide deposition on overall performance, and some operational comments are provided.

Memorandum presenting results of a supersonic flutter investigation of three low-aspect-ratio control surfaces. Two controls were all-movable but the third had a fixed cutout. Results regarding the experiments and calculations are provided.

Memorandum presenting force-oscillation tests made in the 8-foot transonic pressure tunnel to investigate some effects of an overhang-type aerodynamic balance and of a flow spoiler on the dynamic hinge-moment characteristics of a full-span flap-type rudder on a 5-percent-thick, swept vertical fin of low aspect ratio. Test results how that the aerodynamic damping moment on the plain rudder becomes unstable near a Mach number of 0.975 and remains unstable to the maximum speed of the tests.

Report presenting performance of a two-dimensional external-compression inlet designed for various methods of inlet-engine matching up to Mach 3 at Mach 1.89 and Mach 0. Results regarding shock geometry, two-shock ramps, isentropic ramps, profiles, and cowl drag for the various Mach number tests are provided.

Memorandum presenting an investigation of the performance of inlet configurations with a forebody designed for isentropic external compression at a nominal Mach number of 5.6. At zero angle of attack, all the configurations yielded larger total-pressure recoveries than had previously been obtained with a single-conical-shock inlet. Results regarding the flow about the forebody, inlet performance, and performance comparisons are provided.

Memorandum presenting an investigation of hemispherical nose shapes of titanium, stainless steel coated with aluminum oxide, and uncoated stainless steel with lithium hydride and magnesium as internal coolants. Results regarding titanium models, stainless-steel models (uncoated), stainless-steel models coated with aluminum oxide, solution effects on the decomposition temperature of lithium hydride, effect of lithium hydride and magnesium on temperature measurements, and efficiency of models cooled with lithium hydride are provided.

Transonic flutter derivatives for unswept wing control surface configurations determined by pressure cell measurements. The control surfaces were mounted on a wing with an aspect ratio of 3, a taper ratio of 0.6, and a wing-thickness ratio of 0.06. Results regarding aerodynamic balance, vortex generators, splitter-plate configurations, and wedges are provided.

Memorandum describing an investigation using two airplanes, an F6F-3 and F-86A, each fitted with servo equipment for varying in flight the lateral and directional stability and handling characteristics, which have been flown by test pilots to simulate the predicted dynamic behavior of six prototype airplanes. The methods of simulation and the types and ranges of variables considered are presented and the results of the individual programs are discussed.

"A study has been made of a flare-cylinder configuration to investigate its feasibility as a reentry body of an intermediate range ballistic missile. Factors considered were heating, weight, stability, and impact velocity. A series of trajectories covering the possible range of weight-drag ratios were computed for simple truncated nose shapes of varying pointedness, and hence varying weight-drag ratios" (p. 1).

An investigation was conducted on a 35 deg swept-wing fighter airplane to determine the effects of several blunt-trailing-edge modifications to the wing and tail on the high-speed stability and control characteristics and tracking performance. The results indicated significant improvement in the pitch-up characteristics for the blunt-aileron configuration at Mach numbers around 0.90. As a result of increased effectiveness of the blunt-trailing-edge aileron, the roll-off, customarily experienced with the unmodified airplane in wings-level flight between Mach numbers of about 0.9 and 1.0 was eliminated, The results also indicated that the increased effectiveness of the blunt aileron more than offset the large associated aileron hinge moment, resulting in significant improvement in the rolling performance at Mach numbers between 0.85 and 1.0. It appeared from these results that the tracking performance with the blunt-aileron configuration in the pitch-up and buffeting flight region at high Mach numbers was considerably improved over that of the unmodified airplane; however, the tracking errors of 8 to 15 mils were definitely unsatisfactory. A drag increment of about O.OOl5 due to the blunt ailerons was noted at Mach numbers to about 0.85. The drag increment was 0 at Mach numbers above 0.90.

Report presenting an investigation at Mach numbers of 1.61 and 2.01 to determine the pressure distributions for a series of 20 controls on a 60 degree delta wing. Tests occurred at a range of angles of attack and control deflections. Results regarding basic pressure distributions, comparison of experimental and theoretical results, and experimental comparisons are provided.

"Investigations have been made in flight and in wind tunnels to determine which components of turbojet installations are most critical in icing conditions, and to evaluate several methods of icing protection. From these studies, the requirements necessary for adequate icing protection and the consequent penalties on engine performance can be estimated. Because investigations have indicated that the compressor-inlet screen constitutes the greatest icing hazard and is difficult to protect, complete removal or retraction of the screen upon encountering an icing condition is recommended" (p. 1).

"A flight investigation in natural icing conditions was conducted by the NACA to determine the effect of ice accretion on airplane performance. The maximum loss in propeller efficiency encountered due to ice formation on the propeller blades was 19 percent. During 87 percent of the propeller icing encounters, losses of 10 percent or less were observed" (p. 1).

From Summary: "An investigation to determine the effectiveness of icing protection afforded by air-heating hollow steel unpartitioned propeller blades has been conducted In the NACA Cleveland icing research tunnel. The propeller used was a production model modified with blade shank and tip openings to permit internal passage of heated air. Blade-surface and heated-air temperatures were obtained and photographic observations of Ice formations were made with variations In icing intensity and heating rate to the blades. For the conditions of Icing to which the propeller was subjected, it was found that adequate ice protection was afforded with a heating rate of 40 1 000 Btu per hour per blade."

From Summary: "The icing protection afforded an internal air-heated propeller blade by radial partitioning at 50-percent chord to confine the heated air to the forward half of the blade was determined in the NACA Cleveland icing research tunnel. A modified production-model hollow steel propeller, was used for the investigation. Temperatures of the blade surfaces for several heating rates were measured under various tunnel icing conditions. Photographic observations of ice formations on blade surfaces and blade heat-exchanger effectiveness were obtained."

From Summary: "The icing protection obtained from an internally air-heated propeller blade partitioned to confine the heated air forward of 25-percent chord was investigated in the NACA Cleveland icing research tunnel. A production-model hollow steel propeller was modified with an Internal radial partition at 25-percent chord and with shank and tip openings to admit and exhaust the heated air. Temperatures were measured on the blade surfaces and in the heated-air system during tunnel icing conditions. Heat-exchanger effectiveness and photographs of Ice formations on the blades were obtained."

Report presenting an investigation of the ejection release characteristics of the MB-1 rocket from the missile bay of a model of the Convair F-106A airplane with its fin tips retracted at a simulated altitude of 18,670 feet. Successful ejections of the rocket were made at supersonic speeds by applying a combination of ejection velocity and nose-down pitching moment at release.

"The aerodynamic forces on an oscillating airfoil or airfoil-aileron combination of three independent degrees of freedom were determined. The problem resolves itself into the solution of certain definite integrals, which were identified as Bessel functions of the first and second kind, and of zero and first order. The theory, based on potential flow and the Kutta condition, is fundamentally equivalent to the conventional wing section theory relating to the steady case" (p. 291).

Memorandum presenting an icing investigation conducted to determine the general de-icing and runback characteristics of three production samples of electric rubber-clad cyclic de-icing boots. The overall de-icing characteristics of two of the boots investigated were quite similar. Results regarding boot surface temperatures and general de-icing and runback characteristics are provided.

Report presenting an investigation of a model of the Republic F-105 airplane to determine the static longitudinal aerodynamic characteristics of a revised configuration. The revisions included a lengthened fuselage, a relocated canopy, a contoured fuselage afterbody, a ventral fin, and an enlarged vertical tail. Results regarding the effect of stores, effect of dive-brake flaps, effect of forebody modifications, gun blisters, and duct air bleed, and a comparison of the modified model with the original are provided.

"The trajectories of droplets in the air flowing past NACA 65(1)-208 airfoil and an NACA 65(1)-212 airfoil, both at an angle of attack of 4 degrees, were determined. The amount of water in droplet form impinging on the airfoils, the area of droplet impingement, and the rate of droplet impingement per unit area on the airfoil surface affected were calculated from the trajectories and are presented. The amount, extent, and rate of impingement of the NACA 65(1)-208 airfoil are compared with the results for the NACA 65(1)1-212 airfoil" (p. 1).

A lightweight instrument that utilizes resistance-wire electric strain gases to measure propeller-shaft thrust has been developed. A wind-tunnel investigation on a propeller installed, on a single-engine pursuit airplane showed that the instrument gave a reliable indication of propeller-shaft thrust to an accuracy of +/-2 percent within its calibrated range. No attempt was made to determine the relation of indicated shaft thrust to net propeller thrust.