摘要:
The present invention relates to heat exchangers, and more particularly to a heat exchange apparatus configured to operate in a free air stream. In an embodiment, a heat exchange apparatus configured to operate in a free air stream includes a heat exchange structure having a shape configured to conform to a body of a vehicle when in a stowed condition; and a deployment mechanism for moving the heat exchange structure to a deployed condition external to the vehicle. The heat exchange structure has a curved surface that is concave into the air stream when the heat exchange structure is in the deployed condition.
摘要:
In certain embodiments, removing non-condensable gas from a cooling system includes trapping contents of a discharge tube of a heat exchanger, where the heat exchanger is in thermal communication with an ambient environment at an ambient temperature. The contents of the discharge tube comprises a vapor portion of a cooling fluid, a liquid portion of the cooling fluid, and a non-condensable gas. The cooling fluid is at a subambient pressure, and the ambient temperature is lower than a boiling point of the cooling fluid. A first additional portion of the cooling fluid is inlet into the discharge tube to increase a pressure within the discharge tube. The vapor portion of the cooling fluid within the discharge tube is allowed to condense. A second additional portion of the cooling fluid is inlet to purge the non-condensable gas from the discharge tube.
摘要:
A heat sink which comprises an enclosure having a highly thermally conductive surface region and defining an enclosed cavity. A porous, highly thermally conductive material is disposed in the cavity, preferably homogeneously therein, and is thermally coupled to the thermally conductive surface. A phase change material changing from its initial phase, generally solid, to its final phase, generally liquid, responsive to the absorption of heat is disposed in the enclosed cavity and in the porous material. In accordance with a first embodiment, the highly thermally conductive surface region is preferably aluminum and the porous medium is a highly thermally conductive porous medium, preferably aluminum. In accordance with a second embodiment, the thermally conductive surface is composed of highly thermally conductive fibers disposed in a matrix and the porous material is a plurality of the thermally conductive fibers extending from the thermally conductive surface into the cavity. The highly thermally conductive fibers are preferably graphite and the matrix is preferably an epoxy.
摘要:
An apparatus includes a heat receiving portion which receives heat within a footprint from a heat generating structure, and a cooling arrangement which causes flow of a coolant that absorbs heat at the heat receiving portion, the cooling arrangement being disposed in its entirety within a width of the footprint in a particular direction. A different feature involves an apparatus which includes a heat receiving portion at which a coolant receives heat, and a coolant separating portion which receives coolant traveling away from the heat receiving portion, and which separates liquid coolant from vapor coolant.
摘要:
A tail fin assembly for a guided projectile which is capable of withstanding the high pressures experienced during launch, which is also capable of stabilizing the projectile during initial flight shortly after emergence from the cannon or large gun barrel and which is also capable of freely spinning relative to the projectile front section for the remainder of the flight to minimize projectile roll to accomplish all of these capabilities sequentially during a single launch. The assembly includes the projectile and a rotatable member, preferably a tail fin assembly with tail fins which is rotatable about the projectile major axis and which is normally locked against rotation about the projectile. A locking structure is provided for locking the rotatable member against the rotation which is responsive to a predetermined condition to permit rotation of the rotatable member about the projectile. The tail fins are normally retracted and secured to the rotatable member and are extendable in response to a predetermined condition.
摘要:
A transportable hydraulic seismic transducer has a seismic energy source connected to a pad for imparting elastic waves to the underlying ground. The energy source has a reaction mass with a single diameter cylinder formed therein, a double ended piston reciprocally mounted in the cylinder with a piston rod extending from opposite ends of the piston and a pair of bushings fitted within the cylinder at opposite ends to provide bearing surfaces for the opposite ends of the piston rod. A piston may be ringed and a liner fitted into place within the cylinder with the rings forming a seal with the liner. The piston may also be ringless and a liner made of a bushing material fitted within the cylinder so that between the piston and the liner, an adequate seal is provided. The use of the single diameter cylinder or bore permits the total machining of inserted parts such as the bushings and liners to be done before inserting in the reaction mass bore.
摘要:
A dual mode vibrator (DMV), in its hydraulic cylinder, automatically provides a shorter stroke for higher frequencies and a longer stroke for lower frequencies. The cylinder contains a pair of sleeves, each sleeve having one diameter portion sufficient to slideably engage the piston and having a smaller diameter portion to slideably engage the piston rod. The sleeves themselves are moveable within the cylinder, such movement being effected by the application of high pressure on one end or the other. When the sleeves are moved together, the stroke is effectively shortened. When the sleeves are moved apart, the stroke is effectively lengthened.
摘要:
In certain embodiments, removing non-condensable gas from a cooling system includes trapping contents of a discharge tube of a heat exchanger, where the heat exchanger is in thermal communication with an ambient environment at an ambient temperature. The contents of the discharge tube comprises a vapor portion of a cooling fluid, a liquid portion of the cooling fluid, and a non-condensable gas. The cooling fluid is at a subambient pressure, and the ambient temperature is lower than a boiling point of the cooling fluid. A first additional portion of the cooling fluid is inlet into the discharge tube to increase a pressure within the discharge tube. The vapor portion of the cooling fluid within the discharge tube is allowed to condense. A second additional portion of the cooling fluid is inlet to purge the non-condensable gas from the discharge tube.
摘要:
An apparatus includes heat-generating structure disposed in an environment having an ambient pressure, and a cooling system for removing heat from the heat-generating structure. The cooling system includes a fluid coolant, structure which reduces a pressure of the coolant to a subambient pressure at which the coolant has a boiling temperature less than a temperature of the heat-generating structure; and structure which directs a flow of the liquid coolant at the subambient pressure so that it is brought into thermal communication with the heat-generating structure, the coolant then absorbing heat and changing to a vapor.
摘要:
According to one embodiment, a two-phase cooling system includes a condensing heat exchanger fluidly coupled to an evaporator assembly and a pressure controller. The condensing heat exchanger condenses a coolant from a vapor phase to a liquid phase by removing heat from the coolant. The evaporator assembly is thermally coupled to a vacuum tube and operable to receive liquid coolant from the condensing heat exchanger, cool the vacuum tube by evaporating the coolant from the liquid phase to the vapor phase, and transporting the evaporated coolant to the condensing heat exchanger. The pressure controller maintains the pressure of the coolant in the evaporator assembly at a sub-ambient pressure to lower the boiling point of the coolant for reducing the operating temperature of the vacuum tube.