The present disclosure relates generally to synthetic jet ejectors, and more particularly to versatile and modular synthetic jet ejectors and systems incorporating the same.
A variety of thermal management devices are known to the art, including conventional fan based systems, piezoelectric systems, and synthetic jet ejectors. The latter type of system has emerged as a highly efficient and versatile thermal management solution, especially in applications where thermal management is required at the local level.
Various examples of synthetic jet ejectors are known to the art. Earlier examples are described in U.S. Pat. No. 5,758,823 (Glezer et al.), entitled “Synthetic Jet Actuator and Applications Thereof”; U.S. Pat. No. 5,894,990 (Glezer et al.), entitled “Synthetic Jet Actuator and Applications Thereof”; U.S. Pat. No. 5,988,522 (Glezer et al.), entitled Synthetic Jet Actuators for Modifying the Direction of Fluid Flows”; U.S. Pat. No. 6,056,204 (Glezer et al.), entitled “Synthetic Jet Actuators for Mixing Applications”; U.S. Pat. No. 6,123,145 (Glezer et al.), entitled Synthetic Jet Actuators for Cooling Heated Bodies and Environments”; and U.S. Pat. No. 6,588,497 (Glezer et al.), entitled “System and Method for Thermal Management by Synthetic Jet Ejector Channel Cooling Techniques”.
Further advances have been made in the art of synthetic jet ejectors, both with respect to synthetic jet ejector technology in general and with respect to the applications of this technology. Some examples of these advances are described in U.S. 20100263838 (Mahalingam et al.), entitled “Synthetic Jet Ejector for Augmentation of Pumped Liquid Loop Cooling and Enhancement of Pool and Flow Boiling”; U.S. 20100039012 (Grimm), entitled “Advanced Synjet Cooler Design For LED Light Modules”; U.S. 20100033071 (Heffington et al.), entitled “Thermal management of LED Illumination Devices”; U.S. 20090141065 (Darbin et al.), entitled “Method and Apparatus for Controlling Diaphragm Displacement in Synthetic Jet Actuators”; U.S. 20090109625 (Booth et al.), entitled Light Fixture with Multiple LEDs and Synthetic Jet Thermal Management System”; U.S. 20090084866 (Grimm et al.), entitled Vibration Balanced Synthetic Jet Ejector”; U.S. 20080295997 (Heffington et al.), entitled Synthetic Jet Ejector with Viewing Window and Temporal Aliasing”; U.S. 20080219007 (Heffington et al.), entitled “Thermal Management System for LED Array”; U.S. 20080151541 (Heffington et al.), entitled “Thermal Management System for LED Array”; U.S. 20080043061 (Glezer et al.), entitled “Methods for Reducing the Non-Linear Behavior of Actuators Used for Synthetic Jets”; U.S. 20080009187 (Grimm et al.), entitled “Moldable Housing design for Synthetic Jet Ejector”; U.S. 20080006393 (Grimm), entitled Vibration Isolation System for Synthetic Jet Devices”; U.S. 20070272393 (Reichenbach), entitled “Electronics Package for Synthetic Jet Ejectors”; U.S. 20070141453 (Mahalingam et al.), entitled “Thermal Management of Batteries using Synthetic Jets”; U.S. 20070096118 (Mahalingam et al.), entitled “Synthetic Jet Cooling System for LED Module”; U.S. 20070081027 (Beltran et al.), entitled “Acoustic Resonator for Synthetic Jet Generation for Thermal Management”; U.S. 20070023169 (Mahalingam et al.), entitled “Synthetic Jet Ejector for Augmentation of Pumped Liquid Loop Cooling and Enhancement of Pool and Flow Boiling”; U.S. 20070119573 (Mahalingam et al.), entitled “Synthetic Jet Ejector for the Thermal Management of PCI Cards”; U.S. 20070119575 (Glezer et al.), entitled “Synthetic Jet Heat Pipe Thermal Management System”; U.S. 20070127210 (Mahalingam et al.), entitled “Thermal Management System for Distributed Heat Sources”; U.S. 20070141453 (Mahalingam et al.), entitled “Thermal Management of Batteries using Synthetic Jets”; U.S. Pat. No. 7,252,140 (Glezer et al.), entitled “Apparatus and Method for Enhanced Heat Transfer”; U.S. Pat. No. 7,606,029 (Mahalingam et al.), entitled “Thermal Management System for Distributed Heat Sources”; U.S. Pat. No. 7,607,470 (Glezer et al.), entitled “Synthetic Jet Heat Pipe Thermal Management System”; U.S. Pat. No. 7,760,499 (Darbin et al.), entitled “Thermal Management System for Card Cages”; U.S. Pat. No. 7,768,779 (Heffington et al.), entitled “Synthetic Jet Ejector with Viewing Window and Temporal Aliasing”; U.S. Pat. No. 7,784,972 (Heffington et al.), entitled “Thermal Management System for LED Array”; and U.S. Pat. No. 7,819,556 (Heffington et al.), entitled “Thermal Management System for LED Array”.
In one aspect, a device is provided which comprises (a) a plurality of heat sources arranged in a channel, wherein each heat source has a top; and (b) a synthetic jet ejector disposed in said channel; wherein said synthetic jet ejector directs a synthetic jet across the tops of said heat sources.
In another aspect, a computer is provided which comprises (a) a plurality of heat sources; (b) a heat sink spaced apart from said heat sources; (c) a plurality of thermal conductors, each of which is in thermal contact with said heat sink and one of said heat sources; and (d) a synthetic jet ejector which directs a synthetic jet onto or across a surface of said heat sink.
In a further aspect, a synthetic jet ejector is provided which comprises (a) a diaphragm; and (b) a chassis having first and second major surfaces which are equipped with a first set of interlocking features such that a first instance of the synthetic jet ejector releasably attaches to a second instance of the synthetic jet ejector by way of said first set of interlocking features.
The structure of a synthetic jet ejector may be appreciated with respect to
The movement of the flexible diaphragm 111 may be controlled by any suitable control system 117. For example, the diaphragm may be moved by a voice coil actuator. The diaphragm 111 may also be equipped with a metal layer, and a metal electrode may be disposed adjacent to, but spaced from, the metal layer so that the diaphragm 111 can be moved via an electrical bias imposed between the electrode and the metal layer. Moreover, the generation of the electrical bias can be controlled by any suitable device, for example but not limited to, a computer, logic processor, or signal generator. The control system 117 can cause the diaphragm 111 to move periodically or to modulate in time-harmonic motion, thus forcing fluid in and out of the orifice 113.
Alternatively, a piezoelectric actuator could be attached to the diaphragm 111. The control system would, in that case, cause the piezoelectric actuator to vibrate and thereby move the diaphragm 111 in time-harmonic motion. The method of causing the diaphragm 111 to modulate is not particularly limited to any particular means or structure.
The operation of the synthetic jet ejector 101 will now be described with reference to
c depicts the synthetic jet ejector 101 as the diaphragm 111 is controlled to move outward with respect to the chamber 105, as depicted by arrow 127. The chamber 105 has its volume increased and ambient fluid 115 rushes into the chamber 105 as depicted by the set of arrows 129. The diaphragm 111 is controlled by the control system 117 so that, when the diaphragm 111 moves away from the chamber 105, the vortices 123 are already removed from the edges of the orifice 113 and thus are not affected by the ambient fluid 115 being drawn into the chamber 105. Meanwhile, a jet of ambient fluid 115 is synthesized by the vortices 123, thus creating strong entrainment of ambient fluid drawn from large distances away from the orifice 109.
Despite the many advances in synthetic jet ejector technology, a need for further advances in this technology still exists. For example, challenges exist in the implementation of synthetic jet based thermal management systems in laptop and handheld devices, where spatial and geometric constraints make conventional thermal management systems impractical. Similarly, a need exists in the art for a means by which synthetic jet ejectors may be readily modified by end users according to constrains imposed by the end use application, without necessitating a redesign or customization of the synthetic jet ejector or thermal management system. These needs may be met by the systems and methodologies disclosed herein.
It has now been found that synthetic jet ejectors may be utilized advantageously to augment the fluidic flow provided by fan-based thermal management systems—especially in devices having spatial or design constraints—through the provision of channels, passageways or other measures in the host device. This is especially so in such applications involving the thermal management of computing devices, where the turbulent, localized flow provided by synthetic jet ejectors complements the global fluidic flow provided by fans by enhancing heat transfer through boundary layer disruption along the surfaces of a heat sink.
With reference to
With reference to
The thermal management system further includes the fan 215 (see
A synthetic jet ejector 413 is provided which is disposed adjacent to the heat sink 407, and which may also act as the acoustical speaker for the device 401. The synthetic jet ejector 413 is preferably adapted to direct a synthetic jet 411 into each of the channels formed by adjacent pairs of heat fins in the heat sink 407. Consequently, heat from the heat sources 405 is transferred to the heat sink 407 and then rejected to the ambient environment. It will be appreciated, of course, that the use of such thermal conductors 409 allows the heat sources 405 to be thermally managed wherever they are disposed within the device 401, and thus permits significant design flexibility.
In use, almost any number of instances of modular synthetic jet ejectors which are the same as, or similar to, the type depicted in
Several variations are possible with respect to the devices and methodologies disclosed herein. For example, the modular synthetic jet ejectors disclosed herein may be assembled into various articles through various means. In addition to the use of mechanical features to secure the modular units together, various adhesives or fasteners may also be used for this purpose, alone or in addition to such mechanical features. By way of example, in some embodiments, mechanical features may be used to register the modular unit with another modular unit or with a host device or substrate, and a suitable adhesive or fastener may be utilized to fasten the modular units together, or to fasten the modular units to a host device or substrate.
It will further be appreciated that the modular synthetic jet ejector units disclosed herein may be attached or assembled into various devices having various shapes. For example, the resulting device may be L-shaped or T-shaped.
It will also be appreciated that the devices disclosed herein may be powered or controlled by a host device. By way of example, such devices may be incorporated into mobile technology platforms such as, for example, cell phones, smart phones, tablet PCs, and laptop PCs, and may be controlled by the electronic circuitry of the host device. The operating parameters of the incorporated device may be accessible by the host operating system so that the device can be controlled or programmed by software resident on the device. For example, the frequency at which a diaphragm in an incorporated synthetic jet ejector vibrates may be a programmable variable accessible by software operating on the host device.
It will also be appreciated that the devices disclosed herein may have synthetic jet actuators whose chambers are formed by one or more surfaces of the host device. By way of example, the modular synthetic jet actuators disclosed herein may have a chamber with a first surface formed by the host device motherboard, and a second surface formed by the host device chassis.
It will further be appreciated that the devices and methodologies disclosed herein may be utilized to cool or provide thermal management to a variety of heat sources. These include, but are not limited to, any of the components of computers (including those disclosed in the laptop computer of
It will also be appreciated that various dimensions may be utilized in the channels and passageways in the devices and methodologies disclosed herein and illustrated, for example, in
It will also be appreciated that the foregoing passageways may have various geometries. Thus, for example, while it is preferred that these passageways have a geometry that is rectangular in cross-section, embodiments are possible in which the passageway has a geometry that is circular, elliptical, polygonal, or irregular in cross-section.
Finally, it will be appreciated that various types of synthetic jet ejectors may be utilized in the foregoing devices and methodologies. These include synthetic jet ejectors which are based on voice coil technologies, as well as those based on piezoelectric or piezoceramic actuators.
The above description of the present invention is illustrative, and is not intended to be limiting. It will thus be appreciated that various additions, substitutions and modifications may be made to the above described embodiments without departing from the scope of the present invention. Accordingly, the scope of the present invention should be construed in reference to the appended claims.
This application claims the benefit of priority from U.S. provisional application No. 61/768,090, filed Feb. 22, 2013, having the same title, and the same inventors, and which is incorporated herein by reference in its entirety.
Number | Date | Country | |
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61768090 | Feb 2013 | US |