Report presenting an investigation of the performance of a diffuser static-pressure-ratio control with a normal shock-positioning limit on a ramjet engine installed in an altitude free-jet facility. Testing occurred at Mach numbers of 2.35 and 2.50, altitudes of 50,000, 60,000 and 65,000 feet, and angles of attack of 0 and 7 degrees. Results regarding the effects of control constants, effects of disturbance size and operating point, effects of flight conditions, and control limitations and possible improvements are provided.

Injection techniques for fluorine, oxygen, and heptane in 200-pound thrust rocket engine.

"A 1/13-scale model of the forebody of the Republic F-105 with twin-duct wing-root inlets was tested in the Langley 4- by 4-foot supersonic pressure tunnel through a range of angle of attack from -4 deg to 15 deg at a Mach number of 2.01 and a Reynolds number of approximately 3.4 x 10(exp 6) per foot. The tests were made with four configurations which incorporated varying amounts of sweep and stagger of the inlet leading edges, modifications to the areas of the boundary-layer diverter floor plate, and modifications to the area of the boundary-layer diverter bleed slots. The highest overall pressure recovery at an angle of attack of 0 deg (average total-pressure recovery, 0.84 mass-flow ratio, 0.98) was achieved with configuration having an inlet leading-edge sweep angle of 58 deg with no leading-edge stagger" (p. 1).

From Introduction: "The feasibility of closed-loop control of ram-jet-engine thrust is demonstrated in references 1 and 2. The dynamic behavior of a 28-inch-diameter ram-jet engine designed to operate in Mach number range of 2.35 to 2.70 is evaluated herein."

Memorandum presenting a study of the effect of oxide-depositing fuels on engine starting, operation, and performance by using a modified production turbojet engine operated using a trimethyl borate azeotrope as a fuel. Results regarding boric oxide deposition, engine operation and performance, effect of turbine-inlet temperature, and dissipation of boric oxide deposits are provided.

Report presenting testing of a modified production turbojet engine using a trimethyl borate azeotrope as a fuel. Operation with this fuel for 100 minutes produced a 2-percent deterioration in engine speed and only a 1-percent increase in combustor total-pressure loss with the best engine configuration investigated. Results regarding boric oxide deposition, engine operation and performance, effect of turbine-inlet temperature, and dissipation of boric oxide deposits are provided.

Engine dynamics were investigated for supercritical operation of the ram jet at Mach 2.75 over a range of simulated altitudes from 68,000 to 82,000 feet. Indicial-and frequency-response tests were conducted with fuel flow as the input variable. For a wide range of operating points, the response of static or total pressure to fuel flow consisted of a dead time followed by a response form that generally approximated a linear, first-order, lead-lag. The dead time varied significantly only with distance from the combustion zone. The rise ratio and the time constant of the lead-lag function were nearly independent of the pressure sensed.

Report presenting an investigation of a semispan-wing-fuselage model with a 55 sweptback triangular wing of aspect ratio 3.5 with a horn-balanced flap-type control with a partially inset unbalancing tab. Control hinge-moment and effectiveness characteristics were obtained for a range of angles of attack, flap deflections, and tab deflections.

Memorandum presenting a mechanism for the thermal decomposition of sodium, lithium, beryllium, magnesium, aluminum, and boron alkyls and for the reverse reaction, the addition of olefins to metal hydrides. The reactions are shown to be nonradical and to probably proceed through a cyclic intermediate.

Characteristic exhaust velocity over a range of mixture ratios and variations in gas velocity with distance from the injector were measured for six injectors. Comparisons of injector performance showed the gains obtained from oxidant atomization, fuel atomization, and propellant mixing. The results are compared with oxygen and heptane performance and show the effect, which is qualitatively small, of spontaneous propellant ignition on the relation between injection processes and engine performance.

A spike-type nose inlet with sharp-lip cowl was investigated at a free-stream Mach number of 2.5 with water injection in its 16-inch diameter, 11-foot-long subsonic diffuser section. Inlet total temperature of exit with liquid-air ratios of about 0.04 with no apparent change in the critical pressure recovery. The observed temperature drops were less than the theoretically predicted values, and the amount of water evaporated was 35 to 50 percent less than that theoretically possible.

Report presenting power spectral densities of normal load factor obtained for two service operational training flights of a Republic F-84G airplane and three service operational training flights of a North American F-86A airplane in order to indicate the load-factor frequency content and possible uses of power spectral methods in analyzing maneuver load data. Results regarding the spectra of the two different planes, an analytical representation of maneuver load spectrum, and probability distributions are provided.

The performance of a control system designed for variable thrust applications was determined in an altitude free-jet facility at various Mach numbers, altitudes and angles of attack for a wide range of engine operation. The results are presented as transient response characteristics for step disturbances in fuel flow and stability characteristics as a function of control constants and engine operating conditions. The results indicate that the control is capable of successful operation over the range of conditions tested, although variations in engine gains preclude optimum response characteristics at all conditions with fixed control constants.