A simplified procedure is shown for calculating the once-per-revolution oscillating aerodynamic thrust loads on propellers of tractor airplanes at zero yaw. The only flow field information required for the application of the procedure is a knowledge of the upflow angles at the horizontal center line of the propeller disk. Methods are presented whereby these angles may be computed without recourse to experimental survey of the flow field. The loads computed by the simplified procedure are compared with those computed by a more rigorous method and the procedure is applied to several airplane configurations which are believed typical of current designs. The results are generally satisfactory.

"The lifting-surface sidewash behind rolling triangular wings has been derived for a range of supersonic Mach numbers for which the wing leading edges remain swept behind the mark cone emanating from the wing apex. Variations of the sidewash with longitudinal distance in the vertical plane of symmetry are presented in graphical form. An approximate expression for the sidewash has been developed by means of an approach using a horseshoe-vortex approximate-lifting-line theory" (p. 455).

"Large downstream movements of transition observed when the leading edge of a hollow cylinder or a flat plate is slightly blunted are explained in terms of the reduction in Reynolds number at the outer edge of the boundary layer due to the detached shock wave. The magnitude of this reduction is computed for cones and wedges for Mach numbers to 20. Concurrent changes in outer-edge Mach number and temperature occur in the direction that would increase the stability of the laminar boundary layer. The hypothesis is made that transition Reynolds number is substantially unchanged when a sharp leading edge or tip is blunted" (p. 709).

"Two-dimensional porous-well cascade tests of the NACA 65- (l2Al0) 10 and NACA 65-(l2A2I8b)10 blade sections were made at Mach numbers from 0.3 to choking in most cases. Data were obtained at solidities of 1.0 and 1.5 at inlet-air angles of 45 deg. and 60 deg. for both blade sections. With a solid--wall modification to the cascade tunnel, schlieren observations were made of the flow in cascade at a solidity of 1.5 and inlet-air angle of 45 deg. and at a solidity of 1.0 and inlet-air angle of 60 deg" (p. 1).

A pair of combustors and transition liners in a quarter-annular, direct-connect assembly was operated at temperatures up to 2400 degrees F to determine the feasibility of using production-type combustor systems as high-tmeperature gas generators for turbine-cooling studies. Operation at high temperatures for 32 hours was possible when minor liner modifications were made that provided greater cooling-air flow between the turbine casing and interior components.

Memorandum presenting an investigation of the compressor and turbine operating trends during acceleration and deceleration of two hypothetical two-spool turbojet engines. The two engines have the same component performance maps but the arbitrarily specified ratio of outer- to inner-spool moment of inertia for the second engine is 4 times that specified for the first engine. Results regarding the acceleration characteristics and deceleration characteristics are provided.

A flight investigation was made at altitudes of 40,000, 25,000 and 15,000 feet to determine the horizontal-tail loads of the Bell X-5 research airplane at a sweep angle of 58.7 deg over the lift range of the airplane for Mach numbers from 0.61 to 1.00. The horizontal-tail loads were found to be nonlinear with lift throughout the lift ranges tested at all Mach numbers except at a Mach number of 1.00. The balancing tail loads reflected the changes which occur in the wing characteristics with increasing angle of attack. The nonlinearities were, in general, more pronounced at the higher angles of attack near the pitch-up where the balancing tail loads indicate that the wing-fuselage combination becomes unstable.

Report presenting local values of heat-transfer rate and temperature-recovery factor obtained on a transpiration-cooled flat plate. The results show primarily that transpiration cooling in a turbulent boundary layer at M = 2.7 has marked effects on the heat transfer and recovery temperature for nearly uniform air injection along the plate.

Report presenting an investigation at Mach number 1.94 of a series of triangular-wing and body combinations to determine the interference lift, drag, and pitching moment. The models had a series of seven flat-plate triangular wings of varying scale, four with semiapex angles of 30 degrees, and three with semiapex angles of 45 degrees. Results indicated that the interference between the wing and the body gave an increase in lift over the wing and body alone, but at the expense of more drag.

Memorandum presenting a theoretical analysis of an airplane automatic control system incorporating a compensating network. The compensating network is a computing network that has characteristics that are the inverse of the airframe; consequently, airplane dynamics are eliminated from the system response. Results regarding the displacement control system, the velocity command system, and the acceleration control system are provided.

Report presenting an investigation in the 4- by 4-foot supersonic pressure tunnel to determine the effect of changes in body cross-section shape on the aerodynamic characteristics of bodies and wing-body combinations. A series of 13 bodies of a given length and volume but various cross-section shapes were tested at a Mach number of 2.01. The results showed that changes in drag at zero lift due to changes in body cross-section shape from the basic circular shape are small and of the same order as the test accuracy.

Report presenting an investigation of aircraft which are required to maneuver rapidly at extreme altitudes, which involves reaching maximum loads at high angles of attack. Load information is necessary for that flight condition and for aircraft that reach their maximum loads at high speed and high dynamic pressures. Results regarding the wings and wing-body combinations are provided.

Report presenting an investigation of the ditching characteristics of the Boeing 707 jet transport in tank no. 2. Various conditions of damage, landing attitude, and speed were investigated. Data were obtained from visual observations, acceleration records, and motion pictures.

A study relating local-pressure fluctuations to static-pressure distributions on six two-dimensional airfoils. Total-pressure fluctuations and total-pressure loss in the wake of an NACA 65A008 airfoil are also compared. Results regarding local-pressure fluctuations on the models and total-pressure fluctuations in the wake of an NACA 65A008 airfoil are provided.

Report presenting experimental panel flutter data at a range of Mach numbers for buckled rectangular panels and the effect of a pressure differential. Increasing the pressure differential was found to eliminate flutter on most of the panels tested. Results regarding buckled panels clamped on the front and rear edges, bucked panels clamped on four edges, effect of lengthwise stiffeners on the flutter of a buckled panel, and panel flutter stresses are provided.

Memorandum presenting an analysis and evaluation of the meteorological requirements and problems anticipated with the operation of commercial turbojet aircraft. Discussions concerning problems of temperature, wind, pressure, ceiling, visibility, cloud and clear-air turbulence, icing, and communication are included in this study.

Report presenting an investigation to determine the effect of outer-shell design variables on the internal performance characteristics of plug-type nozzles designed for a pressure ratio between 6 and 12. Inlet Mach number and outer-shell angle were found to have no effect on nozzle thrust coefficient. For choked flow, the effective throat area decreased when the inlet Mach number or outer-shell angle was increased.

Report presenting flight tests performed using the Douglas X-3 research airplane during the manufacturer's demonstration program and U.S. Air Force evaluation. Tests were performed over a range of Mach numbers and altitudes. Longitudinal, lateral, and directional stability and control data were obtained during steady and maneuvering flight and are compared with wind-tunnel and rocket-model data in this report.

Report presenting an investigation of the boattail pressures and base pressures of two twin-jet afterbody configurations at Mach number 1.91. They were designed as a simple merging of two blunt-based conical afterbodies with spacings of 1.4 and 1.7 jet diameters between the jet center lines. Results regarding support-strut interference, effect of jet spacing ratio, effect of jet exit angle, longitudinal boattail pressure distribution, circumferential pressure distributions, and effect of a reflection plane are provided.

Report presenting an investigation of NACA 8.75-(5)(05)-037 eight- and six-blade dual-rotating propellers under static conditions. The slipstream-boundary cone angle was found to agree with the theoretical angle of spread for an unheated jet. Results regarding the longitudinal survey, stationary survey, effect of blade angle, nature of flow near propeller, and effect of blade angle on slipstream rotation are provided.

From Introduction: "The objectives of this report are to present methods and information sufficient for a lineralized dynamic description of the significant dependent and independent variables of a turboprop engine."

Report presenting an investigation in the 8- by 6-foot supersonic wind tunnel at several free-stream Mach numbers for a range of primary-nozzle pressure ratios and secondary weight-flow ratios to determine the effects on performance of varying the ejector diameter ratio by simulated iris flaps. Results indicated that increases in ejector gross force and secondary-to-primary total-pressure ratio were obtained subsonically when diameter ratio was reduced, thus reducing overexpansion losses.

Report presenting an investigation to determine the effects of altitude and inlet-pressure distortions on the steady-state and surge characteristics of the J57-P-1 two-spool turbojet engine in the altitude wind tunnel. Steady-state performance and surge fuel flows were obtained with a uniform inlet distribution at a range of altitudes at flight Mach number 0.8.

Report presenting an analysis of losses occurring in a series of subsonic turbine blades in a low-speed two-dimensional cascade and in a related series of four transonic rotors. Results regarding the two-dimensional cascade loss correlations, transonic turbine loss correlations, effect of unsteady flows, and mixing of stator wakes are provided.