Embodiments of the invention relate generally to synthetic jet actuators and, more particularly, to the packaging of synthetic jet actuators.
Synthetic jet actuators are a widely-used technology that generates a synthetic jet of fluid to influence the flow of that fluid over a surface. A typical synthetic jet actuator comprises a housing defining an internal chamber. An orifice is present in a wall of the housing. The actuator further includes a mechanism in or about the housing for periodically changing the volume within the internal chamber so that a series of fluid vortices are generated and projected in an external environment out from the orifice of the housing. Examples of volume changing mechanisms may include, for example, a piston positioned in the jet housing to move fluid in and out of the orifice during reciprocation of the piston or a flexible diaphragm as a wall of the housing. The flexible diaphragm is typically actuated by a piezoelectric actuator or other appropriate means.
Typically, a control system is used to create time-harmonic motion of the volume changing mechanism. As the mechanism decreases the chamber volume, fluid is ejected from the chamber through the orifice. As the fluid passes through the orifice, sharp edges of the orifice separate the flow to create vortex sheets that roll up into vortices. These vortices move away from the edges of the orifice under their own self-induced velocity. As the mechanism increases the chamber volume, ambient fluid is drawn into the chamber from large distances from the orifice. Since the vortices have already moved away from the edges of the orifice, they are not affected by the ambient fluid entering into the chamber. As the vortices travel away from the orifice, they synthesize a jet of fluid, i.e., a “synthetic jet.”
Due to their inclusion of flexible diaphragms piezoelectric actuator elements, it is recognized that synthetic jet actuators are fragile mechanisms. As synthetic jet actuators can be subjected to a range of environment conditions during use, this can lead to occurrences of pre-mature failure and to the need for replacement of the synthetic jet actuators. Such replacement of the synthetic jet actuators can be time consuming and, in some cases, can also necessitate shutdown of the system or components to which the synthetic jet actuators are designed to provide cooling to. It would thus be beneficial for the synthetic jet actuator be protected from the surrounding environment such that the synthetic jet actuator may be protected from temperature extremes, moisture, and physical impact from surrounding components.
Accordingly, there is a need for a system and method for packaging synthetic jet actuators so as to provide protection from environmental conditions. There is a further need for such a system to have minimal impact on the operation and performance of the synthetic jet actuators.
Embodiments of the invention overcome the aforementioned drawbacks by providing a system and method for packaging synthetic jet actuators. Synthetic jet plates and actuator elements of the synthetic jet actuator are mounted within an outer housing in a suspended arrangement such that the housing has a minimal impact on the operation and performance of the synthetic jet actuator.
In accordance with one aspect of the invention, a synthetic jet actuator includes a first plate, a second plate spaced apart from the first plate and arranged parallelly thereto, and a housing positioned about the first and second plates and defining a chamber, the housing having at least one orifice therein such that the chamber is in fluid communication with an external environment. The synthetic jet actuator also includes a mounting mechanism configured to mount the first and second plates within the housing in a suspended arrangement and an actuator element coupled to at least one of the first and second plates to selectively cause deflection thereof, thereby changing a volume within the chamber so that a series of fluid vortices are generated and projected to the external environment out from the at least one orifice of the housing.
In accordance with another aspect of the invention, a method of manufacturing a synthetic jet actuator includes providing an outer housing having a plurality of walls defining a chamber and having an orifice formed in at least one of the plurality of walls and positioning a pair of synthetic jet plates within the outer housing and on opposite ends thereof The method also includes attaching the pair of synthetic jet plates to the outer housing such that the pair of synthetic jet plates are spaced apart from each of the plurality of walls.
In accordance with yet another aspect of the invention, a synthetic jet actuator includes an outer housing defining a chamber and having at least one opening formed therein and a pair of synthetic jet plates positioned within the outer housing and on opposing sides thereof. The synthetic jet actuator also includes a mounting device configured to affix the pair of synthetic jet plates to the outer housing such that the pair of synthetic jet plates are inwardly spaced from the outer housing so as not to be in contact therewith and at least one actuator element coupled to the pair of synthetic jet plates to selectively change a volume within the chamber so that a series of fluid vortices are generated and projected to an external environment out from the at least one opening in the outer housing.
These and other advantages and features will be more readily understood from the following detailed description of preferred embodiments of the invention that is provided in connection with the accompanying drawings.
The drawings illustrate embodiments presently contemplated for carrying out the invention.
In the drawings:
The present invention provides for a system and method of providing a packaged synthetic jet actuator. The packaged synthetic jet actuator includes an outer housing that surrounds synthetic jet plates and actuator elements, which are mounted to the housing in a suspended arrangement.
Referring to
The flexible diaphragm 18 may be controlled to move by any suitable control system 24. For example, the diaphragm 18 may 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 18 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 24 can cause the diaphragm 18 to move periodically, or modulate in time-harmonic motion, and force fluid in and out of the orifice 16. Alternatively, a piezoelectric actuator could be attached to the diaphragm 18. The control system would, in that case, cause the piezoelectric actuator to vibrate and thereby move the diaphragm 18 in time-harmonic motion.
The operation of the synthetic jet actuator 10 is described with reference to
It is recognized that synthetic jet actuators, such as the actuator set forth above, can be subjected to a range of environment conditions during use. In some instances, it is desired that the synthetic jet actuator be protected from the surrounding environment, so as to be protected from temperature extremes, moisture, and physical forces/impacts from surrounding components. As such, it is desired that the synthetic jet actuator be “packaged” in a housing-type structure, such as a cover positioned over piezoelectric elements in the synthetic jet actuator.
Referring now to
The first and second plates 52, 54 and actuator elements 56, 58 are positioned within an outer housing 62 having a plurality of walls 64 that surround the first and second plates 52, 54 and define a chamber or volume 66 within the synthetic jet actuator 50. The outer housing 62 includes therein one or more orifices 68 to place the chamber 66 within outer housing 62 in fluid communication with a surrounding, external environment 70. As shown in
As shown in
Beneficially, V-shaped holders 74 secure first and second plates 52, 54 within outer housing 62 in a manner that allows for unimpeded performance of the synthetic jet actuator 50. That is, as the pair of V-shaped holders 74 used to secure first and second plates 52, 54 are attached to/interfit with short end surfaces 78 of the plates, the V-shaped holders 74 allow for interference-free deflection of the first and second plates 52, 54. Additionally, as the V-shaped holders 74 hold the first and second plates 52, 54 in a “suspended” arrangement in which the plates are spaced apart from the housing 62, no contact is made between the first and second plates 52, 54 and the housing 62 during deflection of the plates induced by actuator elements 56, 58. This lack of contact between plates 52, 54 and housing 62 allows the plates to vibrate at their natural frequency and reduce noise generated by the synthetic jet actuator 50.
Referring now to
The first and second plates 52, 54 and actuator elements 56, 58 are positioned within an outer housing 62 having a plurality of walls 64 that surround the first and second plates 52, 54 and define a chamber or volume 66 within the synthetic jet actuator 84. The outer housing 62 includes therein one or more orifices 68 to place the chamber 66 within outer housing 62 in fluid communication with a surrounding, external environment 70. As shown in
The synthetic jet actuator 84 is secured within the housing 62 by way of a mounting device 86. In the embodiment of the invention shown in
Another embodiment of the invention, is shown in
The first and second plates 52, 54 and actuator elements 56, 58 are positioned within an outer housing 94 that surrounds the first and second plates 52, 54 and define a chamber or volume 66 within the synthetic jet actuator 92. The outer housing 94 includes a pair of V-shaped walls 96 on opposing sides thereof and one or more orifices 68 to place the chamber 66 within outer housing 94 in fluid communication with a surrounding, external environment 70. The synthetic jet actuator 92 is secured within the housing 94 by way of cradles 98 that form a mounting device. Cradles 98 are mounted to an inner surface 100 of the V-shaped walls 96 such that they contact the first and second plates 52, 54. The V-shaped walls 96 allow for the structure formed by first and second plates 52, 54 and support structure 93 to be wedged between the V-shaped walls 96 and supported thereby in a point-contact fashion. This point-contact between plates 52, 54 and housing 94 allows the plates to vibrate at their natural frequency and reduce noise generated by the synthetic jet actuator 92.
As set forth above with respect to
While the synthetic jet actuators of
While the invention has been described in detail in connection with only a limited number of embodiments, it should be readily understood that the invention is not limited to such disclosed embodiments. Rather, the invention can be modified to incorporate any number of variations, alterations, substitutions or equivalent arrangements not heretofore described, but which are commensurate with the spirit and scope of the invention. Additionally, while various embodiments of the invention have been described, it is to be understood that aspects of the invention may include only some of the described embodiments. Accordingly, the invention is not to be seen as limited by the foregoing description, but is only limited by the scope of the appended claims.
Therefore, according to one embodiment of the invention, a synthetic jet actuator includes a first plate, a second plate spaced apart from the first plate and arranged parallelly thereto, and a housing positioned about the first and second plates and defining a chamber, the housing having at least one orifice therein such that the chamber is in fluid communication with an external environment. The synthetic jet actuator also includes a mounting mechanism configured to mount the first and second plates within the housing in a suspended arrangement and an actuator element coupled to at least one of the first and second plates to selectively cause deflection thereof, thereby changing a volume within the chamber so that a series of fluid vortices are generated and projected to the external environment out from the at least one orifice of the housing.
According to another embodiment of the invention, a method of manufacturing a synthetic jet actuator includes providing an outer housing having a plurality of walls defining a chamber and having an orifice formed in at least one of the plurality of walls and positioning a pair of synthetic jet plates within the outer housing and on opposite ends thereof The method also includes attaching the pair of synthetic jet plates to the outer housing such that the pair of synthetic jet plates are spaced apart from each of the plurality of walls.
According to yet another embodiment of the invention, a synthetic jet actuator includes an outer housing defining a chamber and having at least one opening formed therein and a pair of synthetic jet plates positioned within the outer housing and on opposing sides thereof The synthetic jet actuator also includes a mounting device configured to affix the pair of synthetic jet plates to the outer housing such that the pair of synthetic jet plates are inwardly spaced from the outer housing so as not to be in contact therewith and at least one actuator element coupled to the pair of synthetic jet plates to selectively change a volume within the chamber so that a series of fluid vortices are generated and projected to an external environment out from the at least one opening in the outer housing.
The present application is a divisional of and claims priority to U.S. patent application Ser. No. 13/253,356, filed Oct. 5, 2011, which is a continuation of and claims priority to U.S. patent application Ser. No. 12/198,301, filed Aug. 26, 2008 and issued as U.S. Pat. No. 8,083,157, the disclosure of which is incorporated herein.
Number | Date | Country | |
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Parent | 13253356 | Oct 2011 | US |
Child | 14187519 | US |
Number | Date | Country | |
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Parent | 12198301 | Aug 2008 | US |
Child | 13253356 | US |