摘要:
Heat exchanger systems and associated systems and methods for cooling aircraft starters/generators are disclosed. A system in accordance with one embodiment includes a first fluid flow path for a first fluid, a second fluid flow path for a second fluid, and a third fluid flow path for a third fluid. The first and second flow paths are positioned proximate to the third flow path to transfer heat between the third fluid and both the first and second fluids. The third flow path is configured to allow a transfer of heat between the second and third fluids at a first transfer rate when the first fluid carries heat at a first rate, and at a second transfer rate different than the first transfer rate when the first fluid does not carry heat, or carries heat at a second rate less than the first rate. Accordingly, when the heat to be rejected by one fluid is decreased, the heat transfer rate for the remaining fluid can be increased.
摘要:
A heat transfer device for installation in a system having a heat generating element within the system away from which heat is to be transferred is described. The heat transfer device includes a heat pipe having a first portion, a second portion, and a working fluid contained within the heat pipe for transferring heat from the first portion to the second portion. The first portion is disposed in proximity with the heat generating element. The second portion is coupled to the first portion. At least part of the second portion is disposed outside the system to dissipate heat from the heat generating element and the second portion may be variably extended outside the system.
摘要:
Heat transfer devices are described. In one example, a heat transfer device for installation in a system having a heat generating element within the system away from which heat is to be transferred is described. The heat transfer device includes a heat pipe having a first portion, a second portion, and a working fluid contained within the heat pipe for transferring heat from the first portion to the second portion. The first portion is disposed in proximity with the heat generating element. The second portion is coupled to the first portion. At least part of the second portion is disposed outside the system to dissipate heat from the heat generating element and the second portion may be variably extended outside the system.
摘要:
Heat exchanger systems and associated systems and methods for cooling aircraft starters/generators are disclosed. A system in accordance with one embodiment includes a first fluid flow path for a first fluid, a second fluid flow path for a second fluid, and a third fluid flow path for a third fluid. The first and second flow paths are positioned proximate to the third flow path to transfer heat between the third fluid and both the first and second fluids. The third flow path is configured to allow a transfer of heat between the second and third fluids at a first transfer rate when the first fluid carries heat at a first rate, and at a second transfer rate different than the first transfer rate when the first fluid does not carry heat, or carries heat at a second rate less than the first rate. Accordingly, when the heat to be rejected by one fluid is decreased, the heat transfer rate for the remaining fluid can be increased.
摘要:
Heat exchanger systems and associated systems and methods for cooling aircraft starters/generators are disclosed. A system in accordance with one embodiment includes a first fluid flow path for a first fluid, a second fluid flow path for a second fluid, and a third fluid flow path for a third fluid. The first and second flow paths are positioned proximate to the third flow path to transfer heat between the third fluid and both the first and second fluids. The third flow path is configured to allow a transfer of heat between the second and third fluids at a first transfer rate when the first fluid carries heat at a first rate, and at a second transfer rate different than the first transfer rate when the first fluid does not carry heat, or carries heat at a second rate less than the first rate. Accordingly, when the heat to be rejected by one fluid is decreased, the heat transfer rate for the remaining fluid can be increased.
摘要:
An improved cryogenic propellant which can be utilized as an improved rocket fuel, hypersonic vehicle fuel, aircraft fuel, explosive, or coolant is described. The improved cryogenic propellant is illustrated by a mixture of liquid hydrogen and solid methane. As an example, an approximate 50/50 mixture by weight of liquid hydrogen and solid methane has a mixture density approximately 2.0 times that of liquid hydrogen alone. This increase in density is partially offset by a loss in ISP of about 8 percent, compared to that of liquid hydrogen alone, with oxygen. Broadly speaking, more of the improved fuel must be carried for a given mission to compensate for the loss in ISP. However, this weight penalty is offset by the 200 percent increase in density. Increased fuel density reduces fuel tank weight and drag.
摘要:
A thermomechanical analysis apparatus includes a probe assembly supported in substantially weightless contact with a sample material over a range of displacement of the probe by means of a linear motor controlled from a constant current source. The probe assembly is automatically weighed by measuring and storing the value of the current needed to raise the probe, that value is thereafter employed during the analysis mode to maintain the probe assembly in a substantially weightless condition.
摘要:
A damping building structure, in the form of a floor joist, spanning two separated supports. Oscillations in the joist are damped by a pair of overlapping plates which are clamped together by one or more nuts and bolts. One of the plates is secured to the floor joist being damped, and the other of the plates is secured, directly or indirectly, to ground. The friction between the overlapping plates acts to damp any oscillations in the floor joist. A spring may be interposed between one of the plates and the nut or bolthead, and, if desired, a friction material may be sandwiched between the plates. The damping arrangement may be secured to the floor joist at one end, at both ends, or at mid-point of the span between the two supports.
摘要:
A facsimile system has improved features for receiving copy medium and for printing. The system has a cylindrical rotatably driven drum that has an expansion device that allows the drum to expand its effective diameter. When the unit is used as a receiver, a cylindrical loop of copy medium is inserted over the drum, when the drum is in its reduced diameter position. Then the expansion device is actuated to enlarge the diameter and tightly constrain the copy medium. The same device may be used to transmit, since the expansion device utilizes a slot formed along the periphery of the drum. The slot opens to receive the edge of an original document when the expansion device is in the reduced diameter position. The slot closes to retain the document when the expansion device is rotated to the enlarged diameter position. The printing is accomplished by a solenoid actuated hammer that presses a ribbon against the copy medium while the drum rotates.