Abstract: A capillary evaporator (100) for removing heat from a heat source (102), particularly under high heat-flux conditions. The capillary evaporator includes a housing (104) having a plurality of ribs (108) in thermal communication with the heat source when the heat source is present. The ribs define a plurality of vapor channels (110) for receiving vapor (112) caused by the vaporization of working fluid (114) within the evaporator. A capillary wick (106) is located within the housing in spaced relation to the ribs. A bridge (118) interposed between the capillary wick and ribs thermally communicates heat from the ribs to the wick and fluidly communicates the vapor from the wick to the vapor channels. The bridge includes a plurality of fractal layers (FL) each having openings (122) and webs (128) that are scaled in size and number with respect to the immediately adjacent fractal layer and are arranged so that the openings in adjacent layers overlap one another.

Abstract: A heat exchanger (HX) (120) utilizing a working fluid and having a high heat flux transfer capacity. The HX comprises a core (130) having a heat transfer surface (128), a length and a width. Inlet manifolds (140) and outlet manifolds (142) located alternatingly across the width of the core extend the length of the core. Interconnecting channels (144) each fluidly communicate with a corresponding outlet manifold and the two inlet manifolds located immediately adjacent that outlet manifold. Heat exchanger fin (154) in thermal communication with the heat transfer surface (128) generally defines the surface of the interconnecting channels. A pathway directs the working fluid first towards and then away from heat transfer surface (128) in a direction substantially normal to the heat transfer surface. Heat is transferred to or from the working fluid from heat transfer fin (154) as the fluid flows toward and away from the heat transfer surface.

Abstract: A device (10) and method for inducing a longitudinal force into a filament (14) are disclosed. The device includes an enclosure (16) that defines a chamber (18) having a first orifice (32) and a second orifice (42) located in respective opposing end walls. The filament extends through the first orifice, chamber and second orifice. The area of the first orifice is slightly larger than the transverse cross-sectional area of the filament, and the area of the second orifice is larger than the area of the first orifice. The chamber is filled with a pressurized fluid (12), which flows out of the enclosure through the first and second orifices, creating corresponding drag forces (56, 58) on the filament that are in opposite directions to one another.

Abstract: A normal-flow heat exchanger (NFHX) (120) utilizing a working fluid and having a high heat flux transfer capacity. The NFHX comprises a core (130) having a heat-transfer surface (128), a length and a width. An inlet plenum (124) is located at one end of the length, and an outlet plenum (126) is located at the opposite end of the length. A plurality of inlet manifolds (140) extend the length of the core, and a plurality of outlet manifolds (142) extend the length of the core and are located alternatingly with the inlet manifolds across the width of the core. A plurality of interconnecting channels (144) each fluidly communicate with a corresponding inlet manifold and the two outlet manifolds located immediately adjacent that inlet manifold. A heat-exchanger fin (154) is generally located between each pair of immediately adjacent interconnecting channels. In one embodiment, the core comprises a plurality of plate pairs (132) each comprising a heat exchanger plate (136) and a spacer plate (138).

Abstract: A duct is provided having a flattened portion containing a liquid slug of gallium, and a magnetic field is passed through the gallium while an alternating current is also passed through the gallium to produce back and forth motion of the liquid gallium slug in step with the alternating current, enabling compression of working fluid within the duct.

Abstract: A radial flow heat exchanger (20) having a plurality of first passages (24) for transporting a first fluid (25) and a plurality of second passages (26) for transporting a second fluid (27). The first and second passages are arranged in stacked, alternating relationship, are separated from one another by relatively thin plates (30) and (32), and surround a central axis (22). The thickness of the first and second passages are selected so that the first and second fluids, respectively, are transported with laminar flow through the passages. To enhance thermal energy transfer between first and second passages, the latter are arranged so each first passage is in thermal communication with an associated second passage along substantially its entire length, and vice versa with respect to the second passages. The heat exchangers may be stacked to achieve a modular heat exchange assembly (300).

Abstract: A three-phase inverter for small, high speed motors such as a miniature centrifical compressor which has a low voltage, high current requirement. The inverter is supplied with DC power at 28 volts, and produces power of about 50 to 500 watts at about 15 volts, and at frequencies of about 5 to 9 kilohertz. Six D-type flip-flops with clock inputs produce twelve signals which are provided to six bridge drivers. Each bridge driver controls two MOSFET's in series. The MOSFET's are supplied with DC power. Outputs are fed to primaries of adjacent transformers in a circular array. The transformer secondaries are arranged in a star configuration to produce stepped voltage and saw-tooth current output wave forms approximating sinusoids in three phases.

Abstract: An electric discharge machining power supply has a capacitor which is recharged using an inductor. After a spark, a transistor switch is closed, and energy from a source is stored in the inductor. The inductor charge period allows for deionization of the spark gap. After the desired amount of energy has been stored in the inductor, the transistor switch is opened, and the energy in the inductor is transferred to a capacitor. When the capacitor is charged, the gap voltage increases to its breakdown value for spark ignition. Because the energy transfer from the inductor to the capacitor is faster than the spark ignition delay, the capacitor is fully charged before the next spark occurs. After the spark ignition delay, a new spark is generated and the cycle is repeated. Other controls and elements are added. Gap voltage is sensed at a point intermediate two resistors between the source and the discharge electrode. A short across the gap is sensed. An inductor/transformer isolates the power source and spark.

Abstract: The present invention is directed to a compact heat exchanger having a permeable heat transfer element and an impervious heat transfer element. Fluid passes through the permeable element through passages which are substantially normal to the interface between the permeable and impervious elements. The fluid passes into channels which are provided at or near the interface between the permeable heat transfer element and the impervious element. Heat is transferred between the fluid and the permeable heat transfer element by convection as the fluid flows through the permeable element. Heat is transferred between the impervious element and the permeable element by conduction. The permeable element can be formed from one or more plates which bound one or more passages through which the fluid flows or can be formed from various porous material such as sintered powders, rods and metal foams.

Abstract: The present invention is directed to a seal for demountable joints operating over a wide temperature range down to liquid helium temperatures. The seal has anti-extrusion guards which prevent extrusion of the soft ductile sealant material, which may be indium or an alloy thereof.

Abstract: The present invention is directed to a compact heat exchanger having a permeable heat transfer element. Fluid passes through the permeable element to passages which are provided at the interface between the permeable heat transfer element and a high thermal conductivity impervious element. Heat is transferred from the fluid to the permeable heat transfer element as the fluid flows through the permeable element. Heat is transferred to the impervious element from the permeable element and from the fluid as the fluid flows through the passages. Optionally a second fluid is in thermal communication with the impervious element.