This report presents the results of flight measurements of longitudinal stability and control characteristics made on a swept-wing jet aircraft to determine the origin of the pitch-up encountered in maneuvering flight at transonic speeds. For this purpose measurements were made of elevator angle, tail angle of attack, and wing-fuselage pitching moments (obtained from measurements of the balancing tail loads).

"An experimental investigation was conducted to determine the cooling effectiveness of a wide variety of air-cooled turbine-blade configurations. The blades, which were tested in the turbine of a - commercial turbojet engine that was modified for this investigation by replacing two of the original blades with air-cooled blades located diametrically opposite each other, are untwisted, have no aerodynamic taper, and have essentially the same external profile. The cooling-passage configuration is different for each blade, however" (p. 1).

From Introduction: "The data obtained for each configuration are presented in a manner to show the effects of fuel distribution and flame-holder design on net thrust, specific fuel consumption, exhaust-gas temperature, combustion efficiency, operable range of tail-pipe-burner fuel-air ratios, and maximum altitude limit."

A 24-inch-diameter shock-in-rotor supersonic compressor rotor designed to obtain simple radial equilibrium behind the normal shock obtained a maximum total-pressure ratio of 2.02 at an adiabatic efficiency of 0.74 and a weight flow of 61.5 pounds per second at design speed. Although this design method considerably reduced the radial forces, there was no apparent reduction in the radial forces, there was no apparent reduction in the radial redistribution of mass flow over the radial redistribution obtained in the previous investigation. This investigation indicates that the shock boundary-layer interaction pattern and associated effects have a very large effect on the radial redistribution of mass flow through the shock-in-rotor supersonic-compressor rotor.

Report presenting an investigation into the effect of end plates and end-mounted struts on the lift-drag ratios of a hydrofoil at several speeds and Reynolds numbers that were all above the limiting speed of wave propagation. Information about the lift-drag ratio, effective aspect ratio, and comparison of the results versus theoretical calculations is included.

This report presents the results of an investigation to ascertain the lift, drag, and pitching moment of a wing-body combination having a triangular wing of aspect ratio 2 with NACA 0003-63 thickness distribution in streamwise planes and twisted and cambered for a nearly elliptical span load distribution. Results are shown for Mach numbers from 0.60 to 0.90 and from 1.30 to 1.70 at Reynolds numbers of 3.0 million and 7.5 million.

The Mach number and temperature profiles in jets expanding from convergent and convergent-divergent nozzles are presented for several values of nozzle-exit pressure ratio. The effects of jet temperature, Reynolds number, and humidity on jet spreading are briefly evaluated. The results indicated that the downstream Mach number profiles for a heated jet are slightly narrower than those for a unheated jet, whereas the downstream temperature profiles were unaffected by nozzle temperature change, and that the effects of Reynolds number and humidity were negligible.

Experimental side and blade pressure distributions over a series of conical boattails without and with jet flow from the base are presented at a Mach number of 1.91. For the case of no jet flow the methods of characteristics and linearized theory are shown to overpredict the side pressure drag. A semi-empirical theory is presented to predict the effect of boattail angle on base pressure. With the boattail extending to a sharp edge at the nozzle exit, the over-pressure jet is shown to decrease the side pressure drag. Presence of an annular base may eliminate the effect of the jet on the side pressure drag, but the jet effect on the base pressure drag may greatly increase or decrease the total boattail drag.

Report presenting an investigation of water landings in the impact basin with a model with a flat rectangular planing surface, a pulled-up bow, and a simulated landing wheel. Runs were made at several wave conditions, trim ranges, flight-path angles, and beam loadings. The results were found to be applicable in predicting loads and motions exhibited by a flat rectangular ski during impact with a water surface.

Report presenting an experimental investigation of the effectiveness of a horizontal tail on two 47.7 degree sweptback wing-fuselage combinations of aspect ratios 5.1 and 6.0. Various combinations of components were tested, including leading-edge flaps, drooped-nose, split flaps, and double slotted flaps, in addition to the flaps-neutral configuration. The primary purpose of the study was to determine the longitudinal stability characteristics of these wings in combination with the fuselage and tail and to determine if the tail is effective in overcoming the unstable variations in pitching moment prior to maximum lift.

Report presenting a flight investigation at high subsonic, transonic, and supersonic speeds and at high Reynolds numbers to determine the zero-lift drag of an arrow wing-body combination and of the body without the wing. Results regarding the drag coefficient, Reynolds number, and normal-force coefficient against Mach number are provided.

Memorandum presenting the effects of specimen-axis orientation with respect to forging direction on the true stress-strain curves and the fracturing characteristics at room temperature of forged and subsequently heat-treated billets of alloys 16-25-6, S-816, and Inconel X. Results regarding plastic properties and fracture properties are provided.

Memorandum presenting a thermodynamic method of determining the work input to a centrifugal compressor operating with water injection. The method was used to compute the work input to a double-entry centrifugal compressor, which was operated at a design equivalent impeller speed over a range of inlet-water ratios and varying weight flow.

Report presenting a survey of various types of catapults in connection with the problem of accelerating a large car along a track to a speed of 150 miles per hour. A hydraulic jet catapult seems to be the best-suited for the purpose, and various types of design problems are examined.

Memorandum presenting a method for designing a wing to be self-trimming at a given set of flight conditions. The spanwise distribution of load on the wing is made to be approximately elliptical, in an effort to maintain low wing drag. The procedure is illustrated using several examples.

Report presenting some highlights of recent experimental studies of flutter at high speeds. Flutter problems have become more varied with the advent of transonic flight and importance of aeroelasticity, and the flutter field has merged with other aspect of aeroelasticity such as divergence and buffeting. The two main subjects of flutter, classical flutter and stall flutter, are explored in these studies.

"An experimental investigation of a 0.8 hub-tip radius ratio, nontwisted-rotor-blade turbine designed for a stagnation-pressure ratio of 2.5 and an equivalent mean blade speed of 643 feet per second was made in a cold-air turbine with (a) nontwisted stator blades, and (b) twisted stator blades designed to maintain zero rotor-inlet incidence angles. Turbine efficiencies of the order of 0.85 at the design point were obtained with a nontwisted-rotor-blade turbine with a hub-tip radius ratio of 0.80. The turbine with the twisted stator blades gave higher efficiencies at the design point (of the order of 1.5 percentage points) than the turbine with the nontwisted stator blades" (p. 1).

"The pressure distribution and drag were determined for a spherical-nosed axially symmetric body with thin projecting rods at Mach numbers of 1.76, 1.93, and 2.10. The upstream projection distance of the rods was varied over a wide range to study changes in the character of the flow separation and to determine the variation of drag and pressure distribution with tip projection. Drag coefficients between 0.18 and 0.30 were obtained for most tip projections at each Mach number" (p. 1).

Memorandum presenting an investigation on the effectiveness of different slot configurations, which uses the method of making the flow of the cooling air visible. Two methods were used for this purpose: one utilized the traces caused by a reaction between pain spread over the blade surface and a gas mixed with the cooling air, while the second utilized smoke mixed with the cooling air to make it visible. A continuous slot was found to give the best coverage of the cooling-air film.

Report presenting a wind-tunnel investigation of two semispan wing models with 45 degrees of sweepback, an aspect ratio of 5, and a taper ratio of 0.565. One wing had no camber or twist while the other was cambered for a design lift coefficient of 0.4 and twisted to relieve loading at the tip. Results regarding the plane wing, cambered and twisted wing, wing-body combinations, effect of camber and twist, effect of fences, effect of surface roughness, and lift-drag ratio are provided.

"When porcelain enamels or vitreous-type ceramic coatings are applied to ferrous metals, there is believed to be an evolution of hydrogen gas both during and after the firing operation. At elevated temperatures rapid evolution may result in blistering while if hydrogen becomes trapped in the steel during the rapid cooling following the firing operation gas pressures may be generated at the coating-metal interface and flakes of the coating literally blown off the metal. To determine experimentally the relative importance of the principal sources of the hydrogen causing the defects, a procedure was devised in which heavy hydrogen (deuterium) was substituted in turn for regular hydrogen in each of five possible hydrogen-producing operations in the coating process" (p. 269).

Windmilling characteristics of several turbojet and turbine-propeller engines were investigated individually over a wide range of flight conditions in the NACA Lewis altitude wind tunnel. A study was made of all these data and windmilling performance of gas turbine engines was generalized. Although internal-drag, air-flow, and total-pressure-drop parameters were generalized to a single curve for both the axial-flow type engines and another for the centrifugal-flow engine.

"Strain-gages were used to measure blade vibrations causing failures in the third stage of a production 11-stage axial-flow compressor. After the serious third-stage vibration was detected, a series of investigations were conducted with second-stage vane assemblies of varying angles of incidence. Curves presented herein show the effect of varying the angle of incidence of second-stage vane assembly on third-stage rotor-blade vibration amplitude and engine performance" (p. 1).