"The principle of operation of a device to control the distribution of fuel to any number of discharge nozzles of a gas-turbine engine is presented. A description of an experimental model of the device and the results of a bench investigation are presented. This device controlled the flow to four discharge nozzles within 2 percent of perfect distribution over a wide range of fuel flow and was unaffected by uneven discharge-nozzle pressures" (p. 1).

Report presenting the results of an investigation to determine the effect of Mach number on the aerodynamic characteristics of a flying-boat hull with a high length-beam ratio. Information about the drag coefficients, angles of attack for minimum drag, and longitudinal and directional stability is provided.

Report presenting testing on the first of a series of flutter rockets, designated the NACA FR-1-A, which was tested with two identical swept wings. Results regarding the launching, flight, and wing failure are provided.

Report presenting the results of an investigation to determine the effects of several methods of fuel injection on the operational performance of a 20-inch ram jet. Four fuel-injection arrangements using the same flame holder were presented. Results regarding the variation of combustion efficiency, ram-pressure ratio, location of the point of fuel injection, and range of fuel-air ratios over which combustion can be maintained are provided.

Report presenting an investigation of the maximum hovering time, or the time that a helicopter can sustain itself without motion, for helicopters using a reciprocating engine, by ramjet engines at the tips of rotor blades, and by pulse-jet engines at the tips of rotor blades. Testing showed that the reciprocating engine permitted much longer hovering time than the jet-propulsion engines, but the jet-propulsion engines were much lighter and could lift greater disposable loads.

"Results have been obtained by means of a free-flight technique utilizing rocket propulsion which indicate that aileron-rolling-effectiveness characteristics are affected adversely by variations in airfoil section which procedure large increases in the trailing-edge angle" (p. 1).

Memorandum presenting an investigation in the free-flight tunnel to determine the effect of the sloshing of fuel in partly filled, unbaffled tanks on the lateral stability of a free-flying model. Flight tests were made to determine the effects of the water sloshing for different depths of water and various masses and moments of inertia of the model. The sloshing caused small-amplitude, high-frequency lateral oscillations which were superimposed on the normal Dutch roll oscillation so that the lateral motions of the model appeared jerky.

Investigation of a single-offset-duct system designed to prevent entrance of water into a turbojet engine was conducted on a half-scale nacelle model. An investigation was made to determine ram-pressure recovery and radial velocity profiles at the compressor section and icing characteristics of such a duct system. At a design inlet velocity of 0.77, the maximum ram-pressure recovery attained with effective water-separating inlet was 77 percent, which is considerably less than attainable with a direct-ram inlet. Continuous heating of the accessory-housing surface would be required for inlets that have a small ice storage space.

Report presenting an investigation of the distribution of pressure at zero lift over the surface of a swept airfoil of biconvex section. The measured pressures are compare with theoretical values calculated from thin-airfoil theory. Results regarding pressure distributions, drag, and boundary-layer studies are provided.

Report presenting an investigation of combustion occurring downstream of various turbulence promoters in a 20-inch length of a 1 7/8-inch inside-diameter, water-jacketed tubing using premixed vaporized fuel and air. Among the turbulence promoters investigated were flat plates perforated with 1/8-inch diameter holes, 1/4-inch diameter holes, and a single large hole to give 12.4, 17.2, and 21.5 percent open area respectively.

Report presenting an investigation to determine the spin and recovery characteristics of a model of the Douglas AD-2W airplane, which has a large radome installation. Results indicated that the plane has satisfactory erect and inverted spin-recovery characteristics. Information about erect spins, inverted spins, and recommended recovery technique is provided.

Measured values of lift, drag, and pitching moment at M(sub o) = 1.53 are presented for seven wings varying in sweep angle from 60 degrees sweepforward to 60 degrees sweepback. All wings had a cambered, double-wedge section 5-percent thick and a common taper ratio of 0.5. The experimental results are compared with the predictions of the linear theory.

Report presenting flight tests to determine the causes of undesirable dynamic lateral-stability characteristics of an airplane. Various rudder modifications were flight tested with the rudder free and fixed over an indicated airspeed range from approximately 200 to 450 miles per hour. Results regarding rudder-fixed characteristics and rudder-free characteristics are provided.

Memorandum presenting equations for obtaining the wall coordinates of two-dimensional supersonic nozzles. The equations are based on the application of the method of characteristics to irrotational flow of perfect gases in channels. A brief discussion of characteristics as applied to nozzle design is given to assist in understanding and applying the nozzle-design method of the report.

Memorandum presenting a theoretical analysis of the effect of aerodynamic hysteresis on stalling flutter. The results were applied to a given airfoil and correlation of the experimental and theoretical results was found possible by assuming that the angle of aerodynamic lag varies as the slope of the static-lift curve. It was shown that the phenomenon of stalling flutter can at least in some cases be explained on the basis of an aerodynamic lag or hysteresis effect.

Report presenting theoretical calculations made by means of semirigid-flutter theory to determine the effect of centrifugal force on the critical flutter speed of a uniform cantilever beam. Calculations are made on airfoils with fundamental bending frequencies up to 2000 radian per second. Centrifugal force can under certain conditions reduce the critical flutter speed.

Report presenting the results of pitching-moment, lift, and drag measurements on a model of the D-558-1 with speed reduction brakes and a symmetrical profile wing at a range of Mach numbers. Only a small decrement in Mach number is produced with no nose-inlet flow and the speed-reduction brakes deflected.

Report presenting tests at Mach numbers between 1.36 and 2.01 of a twin-scoop duct inlet that had slots in the walls of the duct contiguous to the forebody and immediately behind the inlet. The mass flow and total-pressure recovery through the diffusor were measured during tests in which the slot length was constant and the slot width and ramp angle were varied. Results regarding mass flow and total-pressure recovery are provided.

Report presenting a wind-tunnel investigation using the transonic-bump method to determine the longitudinal stability and control characteristics of a semispan airplane model with a 45 degree sweptback wing and tail at transonic speeds. An increase in the rate of change of the pitching-moment coefficient with lift coefficient at a constant Mach number through the transonic range was noted.

Aerodynamic and icing studies were conducted on a one-half-scale model of an annular submerged inlet for use with axial-flow turbojet engines. Pressure recoveries, screen radial-velocity profiles, circumferential mass-flow variations, and icing characteristics were determined at the compressor inlet. In order to be effective in maintaining water-free induction air, the inlet gap must be extremely small and ram-pressure recoveries consequently are low, the highest achieved being 65 percent at inlet-velocity ratio of 0.86. All inlets exhibited considerable screen icing. Severe mass-flow shifts occurred at angles of attack.

Experiments were conducted with 1000-pound-thrust rocket engine to determine feasibility of cooling convergent-divergent nozzle by internal film of water introduced at nozzle entrance. Water flow of 3 percent of propellant flow reduced heat flow into nozzle to 55 percent of uncooled heat flow. Introduction of water by porous ring before nozzle resulted in more uniform coverage of nozzle than water introduced by single arrangement of 36 jets directed along nozzle wall. Water flow through porous ring of 3.5 percent of propellant flow stabilized wall temperature in convergent section but did not adequately cool throat or divergent sections.

Contains a few measurements of the variation of elevator angle and elevator force with Mach number at 30,000 feet altitude up to a Mach number of 0.85. These data show that the airplane possessed positive static longitudinal stability up to a Mach number of 0.80. A trim change in the nose-down direction occurred for Mach numbers above 0.82.

This report contains the results of a high-speed wind-tunnel investigation of the effectiveness of a 10-percent-chord plain flap on the NACA 65-210 airfoil section. The results include an indication of the lift-producing characteristics and the effectiveness of the 10-percent-chord flap. From a comparison of the characteristics of the 10-percent-chord flap with those of a 20-percent-chord flap it was concluded that, although a reduction in flap-chord ratio from 0.20 to 0.10 lessens the severity of the effectiveness loss at supercritical speeds, the 20-percent-chord flap is more effective throughout the entire range of Mach numbers from 0.3 to 0.875.

Report presenting testing of seven models that from two different wing series: a series of taper ratio 0.5 and differing aspect ratio and a series of aspect ratio 4 and differing taper ratio. Measurements of lift, drag, and pitching moment were made at Mach number 1.53. The aerodynamic parameters generally varied with aspect ratio and taper ratio in the manner indicated by the linear theory.