摘要:
Provided is a testbed for conducting an experiment on a substance in a cryogenic liquid state in a microgravity environment. Such a testbed includes a frame with rectangular nominal dimensions, and a source section supported by the frame for supplying the substance to be evaluated in the cryogenic liquid form. An experiment supported by the frame includes an experiment vessel in fluid communication with the storage tank to receive and condense the substance into the cryogenic liquid state. A sensor senses a property of the cryogenic liquid in the experiment vessel as part of the experiment, and a bus section includes a controller configured to control delivery of the substance to the experiment vessel, and receives property data indicative of the property sensed by the sensor for subsequent evaluation on Earth.
摘要:
A test rig capable to test feed-throughs for cryogenic service is provided. The test rig permits testing feed-throughs under the actual pressure and cryogenic temperature conditions of the anticipated in-service application, without the risk of releasing volatile liquid cryogens in the event of leakage or catastrophic failure of the feed-through. Methods of using the test rig are also disclosed.
摘要:
Provided is a testbed for conducting an experiment on a substance in a cryogenic liquid state in a microgravity environment. The testbed includes a frame with rectangular nominal dimensions, and a source section including a supply of the substance to be evaluated in the cryogenic liquid state. An experiment section includes an experiment vessel in fluid communication with the storage section to receive the substance from the storage section and condense the substance into the cryogenic liquid state. A sensor is adapted to sense a property of the substance in the cryogenic liquid state in the experiment vessel as part of the experiment. A bus section includes a controller configured to control delivery of the substance from the storage section to the experiment vessel, and receive property data indicative of the property sensed by the sensor for subsequent evaluation on Earth.
摘要:
Apparatus for inductive braking of a projectile are disclosed. Embodiments include a receiver that has a unidirectional conductor having a closed conductive pathway that encircles a passageway for a moving projectile. The unidirectional conductor permits current to flow through it in substantially only one direction around the passageway. As the projectile and its associated magnetic field move past the unidirectional conductor, the moving magnetic field induces a current flow through the closed conductive pathway, which in turn generates a magnetic field behind the projectile having the same polarity as the projectile's field. The two fields attract one another, which both exerts a braking force on the projectile and tends to align the two fields. Alignment of these fields centers the projectile away from the passageway wall. Because the unidirectional conductor permits current to flow in substantially only the direction that produces a field having the same polarity as the moving field, the opposite-polarity repulsive magnetic field that would otherwise be generated ahead of the projectile, which would otherwise deflect the projectile from its path, is suppressed. Methods of inductive braking are also disclosed.
摘要:
A hydrogen storage and delivery system is provided having an orifice pulse tube refrigerator and a liquid hydrogen storage vessel. A cooling system, coupled to the orifice pulse tube refrigerator, cools the vessel and abates ambient heat transfer thereto in order to maintain the liquid hydrogen in the vessel at or below its saturation temperature. Hydrogen boil-off, and the necessity to provide continuous venting of vaporized hydrogen are minimized or avoided. In a preferred embodiment, the hydrogen storage vessel has a toroidal shape, and the pulse tube refrigerator is a two stage pulse tube refrigerator and extends within a central void space defined at the geometric center of the toroidal storage vessel. Also in a preferred embodiment, the cooling system includes first and second thermal jackets, each having a substantially toroidal shape and enclosing the storage vessel, wherein each of the thermal jackets is thermally coupled to one of the first or second stages of the pulse tube refrigerator in order to cool the vessel and to abate ambient heat leak thereto. The hydrogen storage and delivery system is particularly suitable for use in vehicles, such as passenger automobiles.
摘要:
Apparatus for inductive braking of a projectile are disclosed. Embodiments include a receiver that has a unidirectional conductor having a closed conductive pathway that encircles a passageway for a moving projectile. The unidirectional conductor permits current to flow through it in substantially only one direction around the passageway. As the projectile and its associated magnetic field move past the unidirectional conductor, the moving magnetic field induces a current flow through the closed conductive pathway, which in turn generates a magnetic field behind the projectile having the same polarity as the projectile's field. The two fields attract one another, which both exerts a braking force on the projectile and tends to align the two fields. Alignment of these fields centers the projectile away from the passageway wall. Because the unidirectional conductor permits current to flow in substantially only the direction that produces a field having the same polarity as the moving field, the opposite-polarity repulsive magnetic field that would otherwise be generated ahead of the projectile, which would otherwise deflect the projectile from its path, is suppressed. Methods of inductive braking are also disclosed.
摘要:
A system for determining the position of a gas/liquid interface of a fluid in a tank having a probe and a controller. The probe has silicon diodes arranged linearly on a substrate. The controller applies power to each of the silicon diodes to make a determination of whether a fluid in which the silicon diode is immersed is a liquid or a gas based on a rate of transfer of heat from the silicon diode to the fluid. A method for determining the phase of a fluid in which a sensor is immersed includes the steps of immersing the sensor in a fluid and increasing power applied to the sensor. The value of a thermal transient of the sensor is then measured and the phase of the fluid is determined based on the measured value of the thermal transient.
摘要:
A densifier is provided which in one embodiment can simultaneously densify two cryogenic liquids at different temperatures. The densifier has an oscillatory power source for generating oscillatory power and a two stage pulse tube refrigerator. The oscillatory power source can be a thermoacoustic heat engine or a mechanical oscillatory power source such as a linear flexure bearing compressor. The first stage densifies a first cryogenic liquid to a first cryogenic temperature, and the second stage densifies a second cryogenic liquid to a second, lower cryogenic temperature. A densified propellant management system also is provided which has a densifier for simultaneously densifying two cryogenic liquids at different temperatures, and a cryogenic temperature probe for measuring the temperature gradient in a cryogenic liquid.
摘要:
Provided is a testbed for conducting an experiment on a substance in a cryogenic liquid state in a microgravity environment. Such a testbed includes a frame with rectangular nominal dimensions, and a source section supported by the frame for supplying the substance to be evaluated in the cryogenic liquid form. An experiment supported by the frame includes an experiment vessel in fluid communication with the storage tank to receive and condense the substance into the cryogenic liquid state. A sensor senses a property of the cryogenic liquid in the experiment vessel as part of the experiment, and a bus section includes a controller configured to control delivery of the substance to the experiment vessel, and receives property data indicative of the property sensed by the sensor for subsequent evaluation on Earth.
摘要:
A sensor assembly includes a main body, a sensor, and a filler. The main body includes an outer surface having a continuously-variable radius of curvature in at least one portion. A sensor in thermal communication with a region of that surface having relatively low radius of curvature is disposed in the assembly recessed from the outer surface. Liquid droplets adhered to the outer surface in this region tend to migrate to a distant location having a higher radius of curvature. The main body has low thermal conductivity. The filler has a relatively higher thermal conductivity and, in embodiments, fills an opening in the outer surface of the main body, providing a thermally-conductive pathway between the sensor and the surrounding environment via the opening. A probe having a plurality of such sensors, and methods of detecting the presence of liquid and phase transitions in a predetermined space are also disclosed.