Patent Application
20090290305
Embodiments are generally related to heatsink devices and systems thereof. Embodiments are also related to air-cooling technology. Embodiments are specifically related to techniques for cooling integrated circuit chips and components thereof. Embodiments are additionally related to heatsink components utilized in avionics.
Electronic cooling has been a major impediment for system size reduction and often dictates external dimensions and form factors for computers and other equipments. Electronic systems are generally provided with a large number of heat-generating components such as, for example, microprocessors, power amplifiers, radio frequency (RF) devices and high-power lasers. The functional integrity of such electronic components can be maintained by keeping the temperature of these components below a predetermined value.
A heat exchanger, for example, can be utilized for efficient heat transfer from heat-generating components to ambient air. Conventional heat exchangers rely on an external air-moving component such as, for example, a blower or a fan, to provide airflow for convective heat transfer. For example, the heat exchanger for a CPU (Central Processing Unit) cooling in a desktop computer includes the use of a finned heatsink and a fan. However, such heat exchangers are generally not adequate for space-constraint applications such as avionic systems in which printed board assemblies (PBA) are often placed in proximity and would only allow low-profile heatsink structures/devices to be mounted onboard and direct fan attachment typically is not feasible.
Aircraft engine bleed air has been utilized for various operational needs such as cabin pressurization, air conditioning, ventilation, and cooling electronic chassis. However, the current depressurized engine bleed air available for avionics cooling requires the use of high-flow duct work, rendering it difficult to reach space constraint areas, such as those found in typical avionics applications.
Based on the foregoing it is believed that a need exists for an improved heatsink that can be adapted for enhanced performance in applications found in avionic systems.
The following summary is provided to facilitate an understanding of some of the innovative features unique to the embodiments disclosed and is not intended to be a full description. A full appreciation of the various aspects of the embodiments can be gained by taking the entire specification, claims, drawings, and abstract as a whole.
It is, therefore, one aspect of the present invention to provide for an improved heatsink.
It is a further aspect of the present invention to provide an entrainment heatsink.
It is yet a further aspect of the present invention to provide for the use of pressurized engine bleed air as the primary flow for an entrainment heatsink.
The aforementioned aspects and other objectives and advantages can now be achieved as described herein. An entrainment heatsink system and method utilizing distributed micro jets is disclosed. Such a system and/or method employ a pressurized primary flow through arrays of micro nozzles to entrain a much larger secondary flow to carry heat away from the heatsink. The pressurized bleed air from an aircraft engine represents an ideal pressurized air source for the primary flow for such a heatsink. As such, the needed high-pressure primary flow is very small and can be delivered via thin tubing, which has the flexibility to reach constraint spaces. In addition to the entrainment effect, the distributed micro jets also induce a high level of turbulence in the heatsink, significantly enhancing heat transfer and cooling performance.
The dense array of micro nozzles and the air channels are incorporated onto the fins of the entrainment heatsink to facilitate the micro jet entrainment and can be fabricated by utilizing various micro fabrication technologies. The heat exchanger disclosed herein incorporates air-moving mechanism directly on the fin surface and eliminates the external fan or blower, which significantly reduces the size thereof. Possible performance for such an approach can include, for example, dissipating 1000 W heat with less than 33 watt power consumption and 0.05 deg C/watt thermal resistances. It can be appreciated, of course, that such parameters are merely suggestions and not considered limiting features of the disclosed embodiments.
The accompanying figures, in which like reference numerals refer to identical or functionally-similar elements throughout the separate views and which are incorporated in and form a part of the specification, further illustrate the embodiments and, together with the detailed description, serve to explain the embodiments disclosed herein.
The particular values and configurations discussed in these non-limiting examples can be varied and are cited merely to illustrate at least one embodiment and are not intended to limit the scope thereof.
The bleed air 140 entering the manifold 145 can be provided in the form of compressed air originating from an aircraft engine (e.g., a turbo jet engine) 410, as illustrated in
As the compressed air exits micro nozzles 330, it attains a jet speed of 100 m/s to 300 m/s depending on the pressure. As the jets interact with the surrounding air, the momentum of the jets is transferred to a much larger amount of air, resulting in the movement of a much larger mass of air at a slower speed (e.g. 1 m/s to 20 m/s), as indicated by arrow 220 in the illustration of
The set of cooling fins 240 can include a set of air channels 320 in fluidic connection with a dense array of micro nozzles 330. As indicated at block 530, the bleed air can be passed through the air channels 320 and the dense array of micro nozzles 330 of the cooling fins 240 via small diameter hoses 130. Finally, as illustrated at block 540, a pressurized primary flow 140 can be employed to create micro jets through the array of micro nozzles 330, thereby entrain a much larger secondary flow to carry heat away from the heatsink 200 and thereby the heatsink system can significantly enhance heat transfer and cooling performance.
Possible applications for such an approach include thermal management for military and commercial avionics. For example, such an approach can be used to cool chips utilized in an Image Process Module for cockpit displays, power amplifiers, RF transmitters, and high power lasers.
It will be appreciated that variations of the above-disclosed and other features and functions, or alternatives thereof, may be desirably combined into many other different systems or applications. Also that various presently unforeseen or unanticipated alternatives, modifications, variations or improvements therein may be subsequently made by those skilled in the art which are also intended to be encompassed by the following claims.
This patent application claims priority to U.S. Provisional Patent Application Ser. No. 61/054,696, entitled “Entrainment Heatsink Using Engine Bleed Air,” which was filed on May 20, 2008, the disclosure of which is incorporated herein by reference in its entirety.
| Number | Date | Country | |
|---|---|---|---|
| 61054696 | May 2008 | US |
