Abstract: An overexpanded thrust vector control nozzle has a converging extension section downstream of the jet exhaust stream deflecting section for defining a restriction or orifice. The orifice functions to elevate the exhaust pressure in the deflection section, which permits a reduction in nozzle size for operation at high and low altitudes. The orifice, which isolates the deflection section from outside ambient pressure, receives a deflected exhaust stream after it is turned in the direction opposite to that of the original stream deflection by the wall of the converging section. Control ports, which are adapted to communicate with a source of pressurized control fluid, are provided in the deflection section to position the exhaust stream.

Abstract: A fuel pump assembly for a gas turbine engine incorporates an impeller pump and a vane pump which are driven by a common drive shaft. A centrifugally operated clutch functions to disengage the vane pump from the drive shaft at a predetermined angular velocity. The vane pump is designed to fulfill dry lift, starting flow and pressure requirements for the engine. The impeller pump, alone, provides fuel to the engine near idle speed and above after the vane pump has been disengaged from the drive shaft.

Abstract: A vane pump has a cam member carried upon a drive shaft in coaxial relationship therewith. The axial sides of the cam member define annular cam surfaces which each engage an array of vanes disposed in a fixedly mounted stator. An interior portion of the drive shaft is hollowed to provide a fluid inlet to passages in the cam member which communicate with the cam surfaces. The cam member is provided with additional passages to receive discharge flow from intervane volumes and direct such flow to the radially outer periphery of the cam member.

Abstract: A thrust augmentation technique wherein a primary gas stream is directionally switched at a high rate to produce flow discontinuities in the interest of increasing efficiency. Apparatus in accordance with the invention includes a fluidic switch, particularly a controlled expansion thrust vector control nozzle, which delivers a pulsating primary gas stream to an eductor or lift surface.

Abstract: Control of a liquid power stream by establishment of a gaseous control flow is disclosed. The gaseous control flow is generated by the withdrawal of air at the boundary of the power stream to thereby create a pressure differential which deflects the power stream. Creation and control of a moving carrier flow to establish a moving boundary whereby the energy of the power stream may be modulated is also disclosed.

Abstract: An exhaust nozzle has two frames each with flow attachment surfaces, mounted on its exit end in diametrically opposed relationship. Side plates are mounted on the sides of the attachment surfaces in such a manner that the plates project inwardly toward the axis of the nozzle. The attachment surfaces and their respective side plates define flow channels which receive only annular sectors of the exhaust stream emanating from the nozzle. Each flow channel is of sufficient radial depth and curvature to permit ambient pressure at a selected location on the attachment surface to detach the exhaust stream. A plurality of passages are provided in each frame for communicating ambient pressure to the respective attachment surfaces. A solenoid operated valve on each frame controls communication between the respective passages and the ambient atmosphere.

Abstract: A fuel control system has a positive displacement gear pump for supplying a metered fuel flow to a gas turbine engine. A variable speed drive mechanism, as constituted by a hysteresis type of electro-magnetic clutch driven by the engine, is operatively connected to the pump for varying the speed of the pump in accordance with a commanded pump speed signal. A scheduling device, which senses various engine parameters, generates a signal indicative of a scheduled fuel flow. The fuel flow signal is, in turn, applied to a function generator which supplies the commanded pump speed signal in accordance with a predetermined relationship between pump speed and fuel flow for the engine sought to be controlled. The relationship between pump speed and fuel flow may be calculated for a wide range of flight conditions since the pressure rise or head across the pump is basically a function of fuel flow. This arrangement obviates the use of a head regulator for highly accurate fuel metering.

Abstract: Fluidic switches characterized by a first divergent region immediately downstream of a nozzle throat and a second downstream region of reduced divergence which will be contacted by a deflected jet. The switches of the present invention include control ports which are normally open to the ambient atmosphere, the ports being located at or near the free stream separation point, and the transition from the first divergent section to the second section is located at or near the attached stream separation point. The switches of the present invention may assume a circular cross-section and when so doing will be provided with a plurality of ribs on the internal surface for preventing circumferential flow about a deflected jet.

Abstract: A hydraulic servo valve assembly and a control system therefor employing a pneumatic sensor-actuator are disclosed. The servo valve assembly comprises a servo-operated power valve assembly including a differential piston, a solenoid operated override and hysteresis adjustment. The valve assembly is a "snap-action" device wherein the power valve differential piston is selectively positioned through use of the pneumatic sensor controlled servo valve to vent the pressure applied to the larger area reaction surface of the piston.

Abstract: A boost pump incorporates a low-flow impeller pump for charging the inlet of a gas producer fuel pump and a high-flow impeller pump for charging the inlet of an augmentor fuel pump. The low-flow pump is connected to a drive shaft so as to be continuously driven thereby. The drive shaft may be placed in driving connection with the high-flow pump through the medium of a friction clutch which is engageable by the application of a fluid pressure. Disengagement of the high-flow impeller, when augmentation is not required, significantly contributes to an increase in pump efficiency and a reduction in heating of the fluid being pumped.

Abstract: A centrifugal type impeller pump has a restricting valve to control the inlet area of the collector for reducing recirculating flow from the collector to the impeller. The restricting valve includes a ring mounted upon the pump housing for rotary and axial motion. Rotary motion is imparted to the ring by an actuator. Cam slots in the ring and pins secured to the housing produce axial motion of the ring as the ring rotates. Precise positioning of the ring is possible because large motions of the actuator can be utilized to provide small changes in ring position. The axial position of the ring is determinative of the inlet area of the collector.

Abstract: A hydromechanical fuel control for a turboshaft engine includes a gas producer control and an independent power turbine governor in series flow relationship. The basic gas producer control includes an acceleration system, a deceleration system and all speed governor to regulate the fuel flow output of the gas producer control. The acceleration system includes a main metering valve which is positioned by a compressor discharge pressure responsive device and the all speed governor. A speed responsive computer mechanism controls the head across the metering valve. The computer mechanism includes an enrichment valve and a start valve and is connected to the shut-off valve lever for the fuel control in such a manner that the mechanism may be controlled by actuation of this lever. The power turbine governor includes a fuel flow reset governor and a deceleration system to prevent flameouts.