Patent Application
20090277993
With continuous advances in technology, electronics are dissipating an increasing amount of power in a decreasing amount of space. This presents significant thermal management challenges to keep junction temperatures of components below maxima for performance and life. Additionally, aerospace platform manufacturers are increasing the use of composite materials in an effort to reduce weight. The replacement of metals, which are excellent heat conductors, with composites, which are poor heat conductors, reduces the effectiveness of sinking heat from electrical components to platform structure
Typically electronics are attached to heat sinks that have fins, pins, or slots and those fins, pins or slots conduct heat directly to the airframe or indirectly to the airframe, through air pockets within the airframe. Because of the historic use of metal in the airframe, the heat could be drawn away from the electronics. With advances in composite materials, the use of the airframe or pockets within the airframe are no longer viable because the composite material cannot conduct the heat away from the electronics.
Other methods of dissipating heat include passive convection cooling systems which are not capable of dissipating the large quantity of heat generated by electrical components. Simultaneously, forced convection cooling systems, which are typically active systems, have significant weight, cost and reliability concerns, due to the use of fans, pumps, reservoirs, and the need for additional electronic drivers.
Systems and methods for a passive, forced convection cooling system for aircraft electronic systems in disclosed herein. An example system for passive forced convection cooling includes, an intake port located in an area of high pressure on an air frame. The system further has an exhaust port located in an area of low pressure on an air frame. The areas of high and low pressure refer to areas of comparatively high and low pressure regions of the exterior ambient environment. Further still, an internal cooling duct connects the intake port with the exhaust port, such that air flows from the intake port through the cooling duct to the exhaust port. Additionally the system contains, at least one heat sink located in proximity of the intake port and orientated inside the cooling duct in order to allow the cool air traveling through the cooling duct to cool the at least one heat sink. A method for passive forced convection cooling includes a constant air flow created through an internal area of an airplane when an intake port is located in an area of high pressure on the airplane and an exhaust port is located on an area of low pressure of the aircraft, the intake port and exhaust port connected by a cooling duct; and a temperature sensitive device that is cooled by a heat sink in communication with the cooling duct.
The preferred and alternative embodiments of the present invention are described in detail below with reference to the following drawings:
Systems and methods for a passive, forced convection cooling system for aircraft electronic systems in disclosed herein. In one embodiment, the system draws air from outside the aircraft through a series of cooling ducts before exhausting the air to the outside environment. The system generally utilizes a heat sink with the cooling ducts to transfer heat from a temperature sensitive device to ambient air.
In one embodiment, one side of the heat sink 308 is thermally coupled to a temperature sensitive device 310 in order to absorb heat quickly and efficiently. The opposite side of the heat sink 308 has fins, pins and/or slots, which are located in the cooling duct 306. Being part of the cooling duct 306 allows air to pass over the fins, pins or slots thereby cooling the heat sink 308. The temperature sensitive device side of the heat sink 308 is sealed from the cooling duct 306 in order to protect the temperature sensitive device 310 from outside contaminants like humidity, deicing fluid, or fuel. The finned, pinned, or slotted side of the heat sink 308 will reside within or against the cooling duct. The side of the heat sink 308 with the electronics is sealed using gaskets, welds, or any other means. The heat sink 308 is generally constructed with aluminum but may also be made of copper, magnesium, carbon foam, or any other standard heat sink material
While the preferred embodiment of the invention has been illustrated and described, as noted above, many changes can be made without departing from the spirit and scope of the invention. Accordingly, the scope of the invention is not limited by the disclosure of the preferred embodiment. Instead, the invention should be determined entirely by reference to the claims that follow.
