Abstract:
A combination of a synthetic jet ejector with a host device is provided. The combination comprises (a) a chamber having an aperture disposed in a wall thereof; (b) a diaphragm disposed in said chamber; and (c) an actuator adapted to vibrate said diaphragm so as to create a synthetic jet in a flow of fluid exiting said chamber through said aperture; wherein said chamber has at least one interior surface which is formed by an element of the host device.

Description:
CROSS-REFERENCE TO RELATED APPLICATION 
       [0001]    This application is a continuation of International Application Number PCT/US2011/40794, filed Jun. 17, 2011, having the same title, and having the same inventors, and which is incorporated herein in its entirety; which application claims the benefit of U.S. Provisional Application No. 61/355,308 filed Jun. 16, 2010, having the same title and the same inventors, and which is incorporated herein in its entirety. 
     
    
     FIELD OF THE DISCLOSURE 
       [0002]    The present disclosure relates generally to synthetic jet ejectors, and more particularly to synthetic jet ejectors having a low form factor. 
       BACKGROUND OF THE DISCLOSURE 
       [0003]    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 solution where thermal management is required at the local level. Frequently, synthetic jet ejectors are utilized in conjunction with a conventional fan based system. In such hybrid systems, the fan based system provides a global flow of fluid through the device being cooled, and the synthetic jet ejectors provide localized cooling for hot spots and also augment the global flow of fluid through the device by perturbing boundary layers. 
         [0004]    Various examples of synthetic jet ejectors are known to the art. Some examples include those disclosed in U.S. 20070141453 (Mahalingam et al.) entitled “Thermal Management of Batteries using Synthetic Jets”; U.S. 20070127210 (Mahalingam et al.), entitled “Thermal Management System for Distributed Heat Sources”; 20070119575 (Glezer et al.), entitled “Synthetic Jet Heat Pipe Thermal Management System”; 20070119573 (Mahalingam et al.), entitled “Synthetic Jet Ejector for the Thermal Management of PCI Cards”; 20070096118 (Mahalingam et al.), entitled “Synthetic Jet Cooling System for LED Module”; 20070081027 (Beltran et al.), entitled “Acoustic Resonator for Synthetic Jet Generation for Thermal Management”; and 20070023169 (Mahalingam et al.), entitled “Synthetic Jet Ejector for Augmentation of Pumped Liquid Loop Cooling and Enhancement of Pool and Flow Boiling”. 
     
    
     
       BRIEF DESCRIPTION OF THE DRAWINGS 
         [0005]      FIG. 1  is a schematic illustration of a prior art synthetic jet ejector in a host device. 
           [0006]      FIG. 2  is a schematic illustration of a first embodiment of a synthetic jet ejector in a host device in accordance with the teachings herein. 
           [0007]      FIG. 3  is a schematic illustration of a second embodiment of a synthetic jet ejector in a host device in accordance with the teachings herein. 
           [0008]      FIGS. 4-16  are illustrations of a first embodiment of an illumination device in accordance with the teachings herein. 
           [0009]      FIG. 17  is an illustration of a first embodiment of an illumination device in accordance with the teachings herein. 
           [0010]      FIG. 18  is a cross-section taken along LINE  18 - 18  of  FIG. 17 . 
           [0011]      FIG. 19  is an illustration of a first embodiment of an illumination device in accordance with the teachings herein. 
           [0012]      FIG. 20  is a cross-section taken along LINE  20 - 20  of  FIG. 17 . 
       
    
    
     SUMMARY OF THE DISCLOSURE 
       [0013]    In one aspect, a combination of a synthetic jet ejector with a host device is provided. The combination comprises (a) a chamber having an aperture disposed in a wall thereof; (b) a diaphragm disposed in said chamber; and (c) an actuator adapted to vibrate said diaphragm so as to create a synthetic jet in a flow of fluid exiting said chamber through said aperture; wherein said chamber has at least one interior surface which is formed by an element of the host device. 
         [0014]    In another aspeca, a light source is provided which comprises (a) a housing element; (b) a heat sink; (c) a first flow channel element which, alone or in combination with said housing element, creates (i) a first set of flow paths for the flow of fluid in a first direction through the light source, and (ii) a second set of flow paths for the flow of fluid in a second direction through the light source; (d) an LED which is in thermal contact with said heat sink; and (e) a synthetic jet ejector which comprises a diaphragm disposed in a chamber; wherein said chamber is in fluidic communication with said first set of flow paths, and wherein said chamber has at least one surface formed by at least one of said housing element and said heat sink. 
       DETAILED DESCRIPTION 
       [0015]    While synthetic jet ejectors have found increasing use as thermal management devices, size limitations have limited their use and effectiveness in several applications. In particular, in some applications, as in certain lighting applications, existing synthetic jet ejectors are found to consume too much space to be accommodated within the frequently tight space constraints of the host device. For example, many common light bulb configurations have profiles whose dimensions are dictated by industry specifications, and hence, illumination devices based on these designs often have little room to accommodate a synthetic jet ejector. This problem is often exacerbated by the design of the synthetic jet ejector, which may not make efficient use of the space available to it in such applications. 
         [0016]    It has now been found that the foregoing needs may be met through the provision of a synthetic jet ejector which utilizes one or more walls or surfaces of a host device to form the housing of the synthetic jet ejector. This approach allows the synthetic jet ejector to be made with a smaller form factor than would be the case if a stand-alone synthetic jet ejector were incorporated into the host device. This approach is especially suitable for use in lighting applications as, for example, when a synthetic jet ejector is used to provide thermal management for a light bulb, because it allows the synthetic jet ejector to make efficient use of the (typically limited and often irregularly-shaped) space available within the host device. 
         [0017]    The foregoing principles may be appreciated with reference to  FIGS. 1-3 .  FIG. 1  illustrates a prior art combination  101  of a host device and a synthetic jet ejector  103  which emits one or more synthetic jets  105 . The synthetic jet ejector  103  is incorporated into the host device which, in the particular embodiment depicted, has first  107  and second  109  opposing surfaces. As seen therein, the space between the first  107  and second  109  opposing surfaces must be great enough to accommodate the synthetic jet ejector  103 , and this space is increased by the thickness of the walls of the synthetic jet ejector  103  which are adjacent to the first  107  and second  109  opposing surfaces. 
         [0018]      FIG. 2  illustrates a first particular, non-limiting embodiment of a combination  201  in accordance with the teachings herein of a host device and a synthetic jet ejector  203  which emits one or more synthetic jets  205 . The synthetic jet ejector  203  is incorporated into the host device which, in the particular embodiment depicted, has first  207  and second  209  opposing surfaces. As seen therein, the space between the first  207  and second  209  opposing surfaces must be great enough to accommodate the synthetic jet ejector  203 . However, in the embodiment depicted, this space has been reduced by utilizing the first wall  207  of the host device as one of the walls of the synthetic jet ejector  203 . 
         [0019]      FIG. 3  illustrates a second particular, non-limiting embodiment of a combination  251  in accordance with the teachings herein of a host device and a synthetic jet ejector  253  which emits one or more synthetic jets  255 . The synthetic jet ejector  253  is incorporated into the host device which, in the particular embodiment depicted, has first  257  and second  259  opposing surfaces. As seen therein, the space between the first  257  and second  259  opposing surfaces must be great enough to accommodate the synthetic jet ejector  253 . However, in the embodiment depicted, this space has been reduced by utilizing both the first wall  257  and the second wall  259  of the host device as walls of the synthetic jet ejector  253 . 
         [0020]      FIGS. 4-16  illustrate a first particular, non-limiting embodiment of an illumination device made in accordance with the teachings herein. In the particular embodiment depicted, the illumination device  301  is a PAR 38 LED spotlight bulb. The illumination device  301  comprises a shell  303  (shown in greater detail in  FIGS. 6 and 10 ) having a first conical end  305  with a threaded electrical connector  307  disposed thereon, and a second parabolic end  309  which houses an electronics package  311 , a synthetic jet ejector housing element  313  (shown in greater detail in  FIGS. 14-16 ), a synthetic jet engine  315  (shown in greater detail in  FIGS. 7-9 ) and a heat sink  317  (shown in greater detail in  FIGS. 11-13 ). 
         [0021]    As best seen in the cross-sectional view of  FIG. 5 , a portion  319  of the heat sink  317 , together with synthetic jet ejector housing element  313 , form a housing for the synthetic jet engine  315 . The resulting synthetic jet ejector thus comprises the synthetic jet engine  315  disposed within this housing. Suitable fasteners  323  (see  FIG. 6 ) are provided to secure the synthetic jet ejector housing element  313  to the heat sink  317 . As best seen in  FIG. 7 , a plurality of synthetic jet nozzles  325  are formed by the synthetic jet ejector housing element  313  and the heat sink  317 . Though omitted for purposes of clarity, in the finished device, one or more LEDs or other light-producing elements will be disposed in the conical cavity of the heat sink  317 . 
         [0022]      FIGS. 17-18  illustrate a second particular, non-limiting embodiment of an illumination device made in accordance with the teachings herein. The illumination device  401  of this embodiment is similar in many respects to the illumination device  301  of  FIGS. 4-7 , but has a slightly different profile, and is equipped with a synthetic jet engine  415  having first  425  and second  427  diaphragms of different sizes. This arrangement provides for an extra deep optics cavity. As with the embodiment of  FIGS. 4-7 , in this embodiment, the heat sink  417  forms one wall of the synthetic jet ejector  419 . 
         [0023]      FIGS. 19-20  illustrate a third particular, non-limiting embodiment of an illumination device made in accordance with the teachings herein. The illumination device  501  of this embodiment is similar in many respects to the illumination device  301  of  FIGS. 4-16 , but is equipped with a different (non-standard) shell  503  having a profile which provides for an even deeper optics cavity than the device of  FIGS. 17-18 . As with the embodiment of  FIGS. 4-16 , in this embodiment, the heat sink  517  forms one wall of the synthetic jet ejector  519 . 
         [0024]    Further details of an embodiment of a synthetic jet engine which may be utilized in the foregoing embodiments may be found in U.S. Ser. No. 13/026,220 (Grimm et al.), entitled “SYNTHETIC JET EJECTOR AND DESIGN THEREOF TO FACILITATE MASS PRODUCTION”, which was filed on Feb. 12, 2011, and which is incorporated herein by reference in its entirety. 
         [0025]    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.