Abstract: A Fiber-fed Pulsed Plasma Thruster (FPPT) utilizes a motor to feed PTFE fiber to its discharge region, enabling high PPT propellant throughput and variable exposed fuel area. A highly parallel ceramic capacitor bank lowers system specific mass. Impulse bits (I-bits) from 0.057-0.241 mN-s have been measured on a thrust stand with a specific impulse (Isp) of 900-2400 s, representing an enhancement from state-of-the-art PPT technology. A 1 U (10 cm×10 cm×10 cm, or 1 liter) volume FPPT thruster package will provide 2900-7700 N-s total impulse, enabling 0.6-1.6 km/s delta-V for a 5 kg CubeSat. A 1 U design variation with 590 g propellant enables as much as ˜10,000 N-s and a delta-V of 2 km/s for a 5 kg CubeSat. Increasing the form factor to 2U increases propellant mass to 1.4 kg and delta-V to 10.7 km/s for an 8 kg CubeSat.

Abstract: A mobile fracking system and methods may include a gas turbine housed at least partially inside a trailer and an exhaust attenuation system configured to receive exhaust gas from the gas turbine. The exhaust attenuation system may include a lower elongated plenum configured to receive exhaust gas from the gas turbine and an upper noise attenuation system that is movably connected relative to a distal end of the lower elongated plenum.

Abstract: An oil thermal management system for a gas turbine engine includes a control system operable to selectively heat oil in the oil system with the heater system greater than a predetermined temperature prior to engine start. A method of starting a gas turbine engine includes sensing an oil temperature with respect to a predetermined oil temperature for engine start; and heating the oil to the predetermined oil temperature for engine start in response to the oil temperature being less than the predetermined oil temperature.

Abstract: A catalytic thruster includes a reaction chamber that extends between first and second opposed chamber ends. The first chamber end includes a thermal standoff cup. There is a catalyst bed in the reaction chamber, and a feed tube extends into the reaction chamber through the thermal standoff cup.

Abstract: A gas turbine includes a compressor, a turbine, and a combustor disposed downstream from the compressor and upstream from the turbine. The combustor includes an end cover. The combustor also includes a flange. The flange includes an internal fluid passage defined within the flange and the flange is coupled to an internal face of the end cover. A fuel port is integrally joined with the flange. The fuel port extends through the end cover between the flange and an inlet positioned outside of the end cover. The inlet of the fuel port is in fluid communication with the internal fluid passage of the flange.

Abstract: Spacecraft thruster systems are disclosed. In some instances, a spacecraft thruster system may include stacked ion thrusters and/or ion thruster layers. The ion thrusters and/or ion thruster layers may be sequentially activated and jettisoned from the thruster system after use.

Abstract: A liquid fuel system for an aircraft engine includes a first fuel supply conduit hydraulically connected to a fuel source, a second fuel supply conduit hydraulically connected to the engine, a fuel return conduit hydraulically connected to the second fuel supply conduit, and a fuel pump. The fuel pump has a main inlet hydraulically connected to the first fuel supply conduit, an outlet hydraulically connected to the second fuel supply conduit, and an intermediate inlet hydraulically connected to the fuel return conduit. The intermediate inlet is located between the main inlet and the outlet and in use has a pressure between the main inlet pressure and the outlet pressure. A method of supplying a liquid fuel to an aircraft engine is also described.

Abstract: The invention provides an electrothermal RF plasma production system and thruster design, and associated components, that may be used in terrestrial applications and/or miniaturized to the mass, volume, and power budget of Cube Satellites (CubeSats) to meet the propulsion needs of the small satellite (˜5 to ˜500 kg) constellations and larger satellite buses.

Abstract: An integrated combustor nozzle includes an inner liner segment; an outer liner segment; and a panel extending radially between the inner and outer liner segments. The panel includes a forward end, an aft end, and a side walls extending axially from the forward end to the aft end. The aft end defines a turbine nozzle having a trailing edge circumferentially offset from the forward end. The inner liner segment has a pair of sealing surfaces, each of which defines a first continuous curve in the circumferential direction. The outer liner segment has a pair of sealing surfaces, each of which defines a second continuous curve in the circumferential direction. In some instances, the curves are monotonic in the circumferential direction. A segmented annular combustor including an array of such integrated combustor nozzles is also provided.

Abstract: A field emission neutralizer is provided. The field emission neutralizer includes a bottom plate and a field emission cathode unit located on the bottom plate. The field emission cathode unit includes a substrate, a shell located on the substrate, a cathode emitter located inside the shell, a mesh grid insulated from the cathode emitter, and a shielding layer insulated from the mesh grid. The cathode emitter includes a cathode substrate and a graphitized carbon nanotube array. The graphitized carbon nanotube array is in electrical contact with the cathode substrate. The graphitized carbon nanotube array is fixed on a surface of the substrate body, and the carbon nanotubes of the graphitized carbon nanotube array are substantially perpendicular to the cathode substrate.

Abstract: An inlet arrangement is disclosed herein for use with a supersonic jet engine configured to consume air at a predetermined mass flow rate when the supersonic jet engine is operating at a predetermined power setting and moving at a predetermined Mach speed. The air inlet arrangement includes, but is not limited to, a cowl having a cowl lip and a center body coaxially aligned with the cowl. A protruding portion of the center body extends upstream of the cowl lip for a length greater than a conventional spike length. The protruding portion is configured to divert air flowing over the protruding portion out of a pathway of an inlet to the supersonic jet engine such that a remaining airflow approaching and entering the inlet matches the predetermined mass flow rate.

Abstract: A combustion staging system has: a splitter; pilot and mains fuel manifolds; mains flow control valves; and fuel servo line. Each mains flow control valve has a chamber containing a piston, the chamber to a piston mains side fed by the mains fuel manifold, and the chamber to a piston servo side fed by the servo line. The piston has an open pilot-and-mains position allowing flow from the chamber mains side to the respective injector mains discharge orifice. The piston prevents flow from the chamber mains side. The piston is movable under a pressure change in the servo line relative to the mains fuel manifold. The system has a servo pump and a hydraulic motor driving it. The servo pump changes fuel pressure. Motive power for the hydraulic motor is fuel diverted from a fuel pump high pressure output, the motor returning the diverted fuel to a low pressure input.

Abstract: The present disclosure provides a thruster device. The device includes a force-generating element mounted to a housing. The element is configured to generate a thrust force for propelling the housing. The element including a first electrode connected to a first input terminal of a power source. A second electrode is spaced apart by a predetermined distance from the first electrode and connected to a second input terminal of the power source. The second electrode includes a second longitudinal axis oriented parallelly to a first longitudinal axis. A dielectric medium is disposed between the electrodes. Upon receiving field emission condition, charged particles available at the first electrode accelerate towards the second electrode for generating a thrust force along a direction of movement of the charged particles. The thrust force is generated when the predetermined distance between the electrodes is shorter than a Rindler horizon defined by the charged particles during acceleration.

Abstract: The present disclosure is directed to a method of operating a combustion system to attenuate combustion dynamics. The method includes flowing, via a compressor section, an overall supply of air to the combustion system; flowing, via a fuel supply system, an overall flow of fuel to the combustion system; flowing, to a first fuel nozzle of the combustion system, a first supply of fuel defining a richer burning fuel-air mixture at the first fuel nozzle; flowing, to a second fuel nozzle of the combustion system, a second supply of fuel defining a leaner burning fuel-air mixture at the second fuel nozzle; and igniting the richer burning fuel-air mixture and the leaner burning fuel-air mixture to produce an overall fuel-air ratio at a combustion chamber of the combustion system.

Abstract: Embodiments of drive equipment for mobile hydraulic fracturing power units and methods for changing and controlling the drive equipment are disclosed. The mobile power units include a gas turbine engine that provides mechanical power to drive shaft which is connected to the drive equipment such that the drive equipment is driven by the engine. The drive equipment may be a hydraulic fracturing pump or an electrical generator. The drive shaft is rotated at a speed suitable for the hydraulic fracturing pump and the electrical generator includes a step up gearbox to increase a rotational speed of the drive shaft for use by the electrical generator. The drive equipment may be secured to a skid that is field changeable with a crane or a fork lift to change the drive equipment at a well pad based on the demands of the well pad.

Abstract: An exemplary gas turbine power plant includes a gas turbine with a compressor having a compressor inlet. A combustion chamber follows the compressor and a turbine follows the combustion chamber. A cross section of the compressor inlet includes an inner sector and an outer sector in relation to the axis of rotation of the compressor. A plurality of feed ducts introduces oxygen-reduced gas into the inner sector of the compressor inlet. The plurality of feed ducts is arranged in the compressor inlet so as to be distributed in a circumferential direction on a circle concentrically with respect to the axis of the gas turbine.

Abstract: An acoustic damper for a rotary machine includes at least one wall, at least one cooling air inlet, at least one outlet, and at least one cap. The at least one wall extends from a back side of a burner front panel such that the at least one wall partially defines a dampening chamber. The at least one cooling air inlet is defined within the back side of the front panel and is configured to channel a flow of cooling air into the dampening chamber. The at least one outlet is defined within the back side of the front panel and is configured to channel the flow of cooling air out of the dampening chamber. The at least one cap is positioned at least partially over the at least one cooling air inlet and is configured to reduce a velocity of the flow of cooling air within the dampening chamber.

Abstract: A combustion section for a gas turbine engine including an inner casing comprising a first material defining an inner diameter of a pressure vessel and a first heat transfer coefficient. A second material is extended at least partially over an outer diameter of the first material. The second material is disposed radially between the first material and a combustor liner. The second material defines a second heat transfer coefficient less than the first heat transfer coefficient.

Abstract: An annular heat shield arrangement for a combustor liner comprises annular heat shield assemblies. The annular heat shield assemblies include heat shield segments circumferentially distributed around an axis of the annular heat shield assembly. The heat shield segments extend from a first lateral edge face to a second lateral edge face, a first overlap joint portion being defined at the first lateral edge face, a second overlap joint portion being defined at the second lateral edge face. The first overlap joint portion and the second overlap joint portion are complementary to form an overlap joint when pairs of the heat shield segments are side by side in any one of the heat shield assemblies. An adjacent pair of the annular heat shield assemblies are connected to one another at an overlap between the pair, and wherein the overlap joints from a first of the annular heat shield assemblies of the pair are circumferentially offset from a second of the annular heat shield assemblies of the pair.

Abstract: A gas turbine engine component comprising: a first component having a receiving aperture extending; a second component having a first surface and a second surface; and a passageway portion including a first end, a second end opposite the first end, and an outer surface extending from the second end to the first end, the passageway portion extending from the second surface of the second component through the receiving aperture of the first component, wherein the outer surface of the passageway portion and the first component define a gap therebetween, the gap fluidly connecting airflow in an airflow path proximate the second surface of the first component to the cooling channel, wherein the gap is configured to direct the airflow along the outer surface and the outer surface is shaped to redirect the airflow in a lateral direction parallel to the second surface such that a lateral airflow is generated.