Abstract: A two-phase heat transfer system includes an evaporator unit configured to receive heat from a source, a liquid line fluidly connected to the evaporator unit, a vapor line fluidly connected to the evaporator unit, and a condenser. The evaporation unit includes a thermal capacitance device and an evaporator integrated with the thermal capacitance device.

Abstract: A method of making an evaporator includes orienting a vapor barrier wall, orienting a liquid barrier wall, and positioning a wick between the vapor barrier wall and the liquid barrier wall. The vapor barrier wall is oriented such that a heat-absorbing surface of the vapor barrier wall defines at least a portion of an exterior surface of the evaporator. The exterior surface is configured to receive heat. The liquid barrier wall is oriented adjacent the vapor barrier wall. The liquid barrier wall has a surface configured to confine liquid. A vapor removal channel is defined at an interface between the wick and the vapor barrier wall. A liquid flow channel is defined between the liquid barrier wall and the primary wick.

Abstract: An evaporator includes a cylindrical barrier wall, and a cap that fits at an end of the cylindrical barrier wall. The cylindrical barrier wall defines a central axial opening and an outer cylindrical surface. The cap includes an outer surface that is external to the central axial opening and an inner surface that abuts the central axial opening. A portion of the outer cylindrical surface is configured to define a liquid port extending through the outer cylindrical surface of the cylindrical barrier wall.

Abstract: A bond joint and process of bonding metal parts to one another to form seamless, hollow metal articles, particularly made from beryllium. Tooling is assembled to the parts, prior to hot pressing, to cause pressure to be applied to flanges that extend peripherally from the parts. The parts, assembled together with the tooling, are then subjected to hot isostatic pressing of the flanges at a temperature of about 1700° F. to 1750° F., and at a pressure of about 2000 psi to 2500 psi, for around 3 hours. The tooling surrounding the metal parts functions to limit the amount of compression of the flanges. Articles formed by this process are particularly useful in space flight applications because they are formed of a homogeneous material. This means that the articles can operate under high pressure despite being subjected to temperature cycling. Strength of the bond joint is enhanced because no filler metal is used.

Abstract: A collimator is compact and uses power efficient light emitting diodes as the illumination source to generate a test image in collimated space. The collimator provides a test image across a wide field of view, which is useful for calibration of optical devices that have a wide field of regard. An optical projection system in the collimator utilizes an array of light emitting diodes, whose light is converged by a Fresnel lens, through a holographic diffuser plate, onto a target plate bearing the test pattern to be projected out into collimated space through a converging lens. An alignment structure provides translation of the target plate along the main axis of the collimator and provides rotational freedom about two axes (vertical and horizontal) via a gimbal structure mounted on the translation mechanism.

Abstract: A system includes a heat transfer system and a priming system coupled to the heat transfer system. The heat transfer system includes a main evaporator having a core, a primary wick, and a secondary wick, and a condenser coupled to the main evaporator by a liquid line and a vapor line. A heat transfer system loop is defined by the main evaporator, the condenser, the liquid line, and the vapor line. The priming system is configured to convert fluid into a liquid capable of wetting the primary wick of the main evaporator. The priming system includes a priming evaporator coupled to the vapor line, and a reservoir in fluid communication with the priming evaporator and coupled to the secondary wick of the main evaporator by a secondary fluid line.

Abstract: A capillary wick for use in capillary evaporators has properties that prevent nucleation inside the body of the wick, resulting in suppression of back-conduction of heat from vapor channels to the liquid reservoir. Use of a central liquid flow channel in the wick is eliminated, and pore size in the wick is chosen to maximize available pressure for fluid pumping, while preventing nucleation in the wick body. The wick is embodied with different geometries, including cylindrical and flat. A flat capillary evaporator has substantially planar heat input surfaces for convenient mating to planar heat sources. The flat capillary evaporator is capable of being used with working fluids having high vapor pressures (i.e., greater that 10 psia). To contain the pressure of the vaporized working fluid, the opposed planar plates of the evaporator are brazed or sintered to opposing sides of a metal wick. Additionally, a terrestrial loop heat pipe and a loop heat pipe having overall flat geometry are disclosed.

Abstract: A capillary pump two phase heat transport system that combines the most favorable characteristics of a capillary pump loop (CPL) with the robustness and reliability of a loop heat pipe (LHP). Like a CPL, the hybrid loop has plural parallel evaporators, plural parallel condensers, and a back pressure flow regulator. Unlike CPLs, however, the hybrid system incorporates elements that form a secondary loop, which is essentially a LHP that is co-joined with a CPL to form an inseparable whole. Although secondary to the basic thermal management of the system thermal bus, the LHP secondary loop portion of the system provides for important operational functions that maintain healthy, robust and reliable operation. The LHP secondary loop portion provides a function of fluid management during start-up, steady state operation, and heat sink/heat source temperature and power cycling.