Abstract: A monogroove heat pipe has a single central manifold communicating with plural parallel connected evaporators and a single condenser. The invention is directed to a tubular screen device which is axially positioned within the liquid channel of the manifold. A number of longitudinally spaced holes are formed in the body of the screen device, each hole being defined by cusp edges which are turned outwardly from the screen body into joint ends of the condenser and evaporator liquid channels. The existence of the screen material at the joint between condenser, evaporators, and the manifold assists the establishment of a primed condition in the heat pipe, even in a zero "g" environment for any initial liquid distribution within the heat pipe.

Abstract: An improved capillary pumped loop evaporator includes circumferential grooves formed in the outer heat exchanger portion of the evaporator. The grooves open to the interface existing between the heat exchanger and a centrally positioned tubular wick. Axially extending vapor channels are formed in the wick and also open onto the interface. The circumferential grooves continuously communicate with the interface and provide a vapor escape to the vapor channels which direct vapor passage from the evaporator. By shortening the vapor path from the interface, a thinner vapor barrier is possible at the interface which results in more efficient heat transfer.

Abstract: A leading edge construction for reducing drag on an airfoil, the construction includes a relatively thin solid plate extending forwardly from the air foil, the plate having an exposed top surface and an exposed bottom surface, and a relatively sharply radiused forward edge forming the leading edge of the air foil. The construction further includes slots adjacent to the top and bottom surfaces of the plates for injecting coolant over the top and bottom surfaces of the plate, toward the leading edge, to provide active cooling of the plate for removing stagnant heat lead.

Abstract: A variable conductance heat pipe includes an electronic component mounting plate serving as the evaporator of the heat pipe. The evaporator is connected to an air cooled condenser which condenses vapor flowing from the evaporator. The evaporator has a sump located at the lowest gravity point of the evaporator passage. By either vaporizing or pumping liquid from the sump and passing it back through the heat pipe a continuing wetted condition exists in the heat pipe which can accommodate heat dissipation transients by the electronic components. A control loop is closed through the heat pipe for controlling the penetration of an inert gas into the heat pipe condenser to maintain a constant temperature for the electronic components mounted thereto.

Abstract: A re-entrant groove heat pipe provides capillary channel fin surfaces which are smooth, continuous, and offer a large radius of curvature upon which an extended thin film of working liquid may develop. Superior formation of thin films of the working fluid allows heat to be conducted more readily between the surface of the heat pipe and the surface of the fluid where evaporation and condensation takes place.

Abstract: An interrupted monogroove slot in a heat pipe facilitates priming of the heat pipe under zero gravity conditions by preventing the monogroove slot from completely priming before the liquid channel is primed.

Abstract: A serpentine continuous vapor passage is formed in a metal card which mounts electronic components. Elongated channels of the passage evaporate the contained liquid in response to conducted heat from mounted electronic components. By mounting the side edges of the card to heat conductive retaining means, the evaporated fluid becomes condensed at end sections of the passage thereby transferring the heat from the card and converting the evaporated liquid in a gaseous state back to a liquid state. The resultant card is gravity-insensitive and a thermal-resistance path is minimized so that the cooling capability of the card becomes maximized.

Abstract: An enclosure covers equipment to be camouflaged from thermal or multi-spectral (thermal, radar visual) detection in spaced relation with the equipment. The enclosure is preferably semi-transparent plastic material sufficiently spaced from the equipment to permit natural convection, or forced airflow over the equipment. In one embodiment, the plastic material has a number of sides with a plurality of openings formed therein for entraining air and a top joining the sides. A chimney is formed in the top and an adjustable discharge damper is provided in the chimney for controlling the flow of air over the equipment. The airflow may be natural or controlled actively or semi-actively.

Abstract: A thermal pipe switch includes a single vapor channel communicating with two parallel formed liquid channels. Each of the liquid channels is connected to a respective liquid channel in a dual heat sink assembly which thermally contacts a cryocooler. If a first cryocooler becomes operative, liquid in the heat pipe thermal switch will fill a liquid channel communicating with the heat sink liquid channel which thermally contacts an operative cryocooler. The other heat pipe thermal switch liquid channel is filled with vapor so as to thermally decouple its respectively connected thermal cooler from the system.

Abstract: A heat pipe radiator system is rendered more survivable against laser attack while providing higher thermal performance with significantly lower weight. In order to achieve these advantages, the radiator fin is fabricated from carbon-carbon material which is quite resistant to laser destruction as well as exhibiting twice the thermal conductivity of ordinary metals, such as aluminum. An integral clamp secures the fin to each heat pipe, thereby thermally decoupling the fin from the heat pipe when layer heating occurs. A mesh heat pipe wick creates a vapor barrier in the interior of the heat pipes so that continuous operation of the heat pipe is ensured, even when the pipes are subjected to localized laser heating. The heat pipes are wrapped in multi-layer metal foil insulation to greatly reduce direct laser heating of the heat pipes.

Abstract: A heat pipe including evaporator and condenser sections is located within a stack for reclaiming vaporized metals. The heat pipe is a variable conductance design which employs a communicating reservoir of non-condensable gas for creating a variably positioned interface with the working fluid within the condenser of the heat pipe. The interface varies as a function of the heat load on the condenser and effectively provides a variable control for maintaining efficient, fairly constant heat transfer across the wall of the condenser. Fixed turbulators are mounted to a lower section of the heat pipe for mixing the vaporized metals flowing through the stack thereby increasing the efficiency of heat transfer between the vaporized metals and the heat pipe. The result is a compact and environmentally rugged heat pipe design.

Abstract: A thermal management system using heat pipe principles and incorporating capillary-pumped equipment mounting panels such that a heat transport loop without moving parts is provided. The panels can function to either absorb heat or to reject heat and can interface with heat generating equipment or heat radiators. Each panel comprises a pair of coextensive flat plates bonded together with a thin, fine-pore sheet wick interposed therebetween. A network of liquid grooves in one plate is in fluid communication with the sheet wick which covers the grooves and most of the plate and a separate liquid line connecting the panels. A network of vapor channels in the other plate is in fluid communication with the wick and with a separate vapor line connecting the panels. The vapor channel networks of the panels and the liquid groove networks of the panels are connected such that the panels are arranged in parallel in the fluid circuit or loop.

Abstract: A thermal management system using heat pipe principles and incorporating capillary-pumped equipment mounting panels such that a heat transport loop without moving parts is provided. The panels can function to either absorb heat or to reject heat and can interface with heat generating equipment or heat radiators. Each panel comprises a pair of coextensive flat plates bonded together with a thin, fine-pore sheet wick interposed therebetween. A network of liquid grooves in one plate is in fluid communication with the sheet wick which covers the grooves and most of the plate and a separate liquid line connecting the panels. A network of vapor channels in the other plate is in fluid communication with the wick and with a separate vapor line connecting the panels. The vapor channel networks of the panels and the liquid groove networks of the panels are connected such that the panels are arranged in parallel in the fluid circuit or loop.

Abstract: A screen mesh artery (50) supported concentrically within the evaporator section (20) of a heat pipe liquid channel (27) retains liquid (41) in the channel (27) and thereby assures continued and uniform liquid feed to the heat pipe evaporation section (20) during periods of excessive heat transfer.

Abstract: A method for thermally pumping volatile liquids and a pump for use therewith. The pump has an inlet liquid cooled pump chamber having therein a porous inlet membrane and a porous exit membrane defining between them a pump volume. The membranes are permeable to the liquid phase of the fluid being pumped but, when saturated with liquid, are not permeable to the vapor phase of the fluid. A passive check valve system permitting the passage of liquid but preventing the passage of vapor therethrough is thus formed by the membranes. A baffle plate with a heater located in a concavity therein is positioned in the pump volume adjacent the inlet membrane. The pump output is connected to the inlet of a suitable heat transfer system preferably of the heat-pipe type. With the pump filled with liquid, pumping is initiated by turning on the heater, forming a vapor bubble in the liquid in the pump volume.

Abstract: A heat pipe comprising an elongated sealed metallic envelope having at least a pair of longitudinal channels extending along the length thereof. One of the channels is for the circulation of the vapor phase of the working medium in operation and the other for the liquid phase and capillary means are provided to furnish fluid communication therebetween. Dedicated vapor and liquid channels result in low viscous pressure drops, the capillary communication means and circumferential grooving in the vapor channel provide high capillary pressure differences, and circumferential grooving is provided to furnish the high evaporation and condensation film coefficients required. To support higher heat fluxes, wicking can be used to augment the capillary flow from the liquid channel. To support higher evaporator heat flux without the need for wicking means, the heat pipe can be provided with more than one liquid channel, each communicating with the vapor channel by capillary means.

Abstract: A wick system is disclosed comprising a casing, a wall capillary and a mesh screen wick having at least one artery structure used in conjunction with a closed or open system while in contact with the wall capillary. The wick system may be used in a vertical or inclined position with a condenser at the top.