The present disclosure relates to generally to pumps, and more particularly to a dielectric barrier discharge pump apparatus and method which enables a fluid jet to be generated through the creation of an asymmetric plasma field, and without the need for moving parts typically associated with fluid pumps.
The statements in this section merely provide background information related to the present disclosure and may not constitute prior art. In many applications, it would be desirable to be able to accelerate a fluid flow (e.g., an air flow, an exhaust flow, a gas flow, etc.) within a duct or other form of confined area through which the fluid is flowing or to form a fluid jet for expulsion, injection, or mixing of a fluid or for aerodynamic control or propulsive purposes. In some cases, this can be particularly difficult with the use of conventional pumps or like devices. For one, there is the difficulty of physically mounting a pump within a duct or conduit. Another challenge is that the pump may need to be of a physical size that would cause it to significantly obstruct the fluid flow through the duct, or conversely to require the diameter of the duct or conduit to be unacceptably large. Still further, a conventional pump, which may require that it be driven by an electric motor, will typically have a number of moving parts. The presence of a number of moving parts, in the motor or in the pump itself may give rise to required periodic maintenance and/or repair, which may be difficult and time consuming if the pump is mounted within a duct or conduit. Conventional pumps may also be noisy and have an appreciable weight that limits their use in various applications.
The present disclosure relates to a dielectric barrier discharge apparatus and method that is especially well suited for use as a pump within a duct through which a fluid (e.g., air flow, gas flow, exhaust flow, etc.) is flowing. In one embodiment the apparatus comprises a first dielectric layer having a first electrode embedded therein. A second electrode is disposed at least partially in the air gap, upstream of the first electrode relative to a direction of flow of the fluid flow. A high voltage source supplies a high voltage signal to the second electrode. The electrodes cooperate to generate an asymmetric plasma field in the air gap that creates an induced air flow within the air gap. The induced air flow accelerates the fluid flow as the fluid flow moves through the air gap.
In various embodiments two or more spaced apart dielectric layers are used with each having at least one embedded electrode. An exposed electrode is positioned in the air gap between the dielectric layers. A pair of asymmetric, opposing plasma fields are generated that help to accelerate flow through the air gap.
In one implementation a method is disclosed for forming a fluid flow pump for accelerating a fluid through a duct. The method may comprise:
disposing a first electrode at least partially within a first dielectric layer;
disposing said first dielectric layer within the duct;
disposing a second electrode at least partially within a second dielectric layer;
disposing the second dielectric layer within the duct so as to be in generally facing relation to the first dielectric layer, and such that an air gap is formed between the first and second dielectric layers;
positioning a third electrode within the duct such that the third electrode is located at least partially within the air gap and towards an upstream end of the dielectric layers, relative to a direction of flow of the fluid through the air gap; and
electrically exciting the third electrode to cause the third electrode, the first electrode and the second electrode to cooperatively generate opposing, asymmetric electrical fields within the air gap, to thus generate an induced flow through the air gap. The induced flow operates to accelerate the fluid as the fluid flows through the air gap.
In various embodiments and implementations, a greater plurality of electrodes may be employed to form a plurality of spaced apart air gaps through which a fluid flow may be accelerated.
Further areas of applicability will become apparent from the description provided herein. It should be understood that the description and specific examples are intended for purposes of illustration only and are not intended to limit the scope of the present disclosure.
The drawings described herein are for illustration purposes only and are not intended to limit the scope of the present disclosure in any way.
The following description is merely exemplary in nature and is not intended to limit the present disclosure, application, or uses. It should be understood that throughout the drawings, corresponding reference numerals indicate like or corresponding parts and features.
Referring to
Referring further to
The apparatus 10 further comprises an alternating current (AC) high voltage source 28, which is preferably generating an output of about 1 KVAC-100 KVAC, peak-to-peak, depending on the electrical strength and thickness of the dielectric. The output 30 of the AC voltage source 28 is applied to a third (i.e., non-embedded) electrode 32. The third electrode 32 is supported within the duct 16 in any suitable manner, such as by one or more radially extending struts (not shown). The third electrode 32 is also disposed adjacent upstream ends 34 of the dielectric layers 18 and 20. By “upstream end”, it is meant a position that is towards an upstream side of the dielectric layers 18 and 20 when considering the direction of flow of a fluid 36 through the duct 16. In this example, since the fluid 36 is flowing left to right through the duct 16, the upstream end 34 of the dielectric layers 18 and 20 is the left side of the dielectrics layers 18 and 20. While the third electrode 32 is shown in
The operation of the AC voltage source 28 is controlled by the controller 12. The controller may control the AC voltage source 28 such that the AC voltage source 28 generates high voltage pulses of a desired frequency. The wave form of the high voltage source may be sinusoidal, square wave, saw-tooth, or a short duration (nanosecond) pulse, or any combination of these pulses. Any other control scheme may be implemented depending on the particular needs of a given application.
The dielectric layers 18 and 20 are illustrated in
In operation, the AC voltage source 28 applies a high voltage signal on output line 32 that electrically energizes the third electrode 32. This enables the third electrode 32, the first electrode 22 and the second electrode 24 to cooperatively form a pair of asymmetrically accelerated plasma fields 38 and 40. By “asymmetric”, it is meant that the strength of the force on the plasma field is greater in the downstream direction as shown, which is indicated by the tapering shape of each field 38 and 40 as the fields extend towards the downstream ends 42 of the dielectric layers 18 and 20. The asymmetric plasma fields 38 and 40 create an induced air flow 44 though the air gap 26. The induced air flow 44 operates to accelerate the flow of the fluid 36 flowing through the duct 16. The fluid 36 may be an exhaust gas, or may be an air flow, or it may comprise virtually any form of ionizable gas.
A number of different embodiments of the apparatus 10 may be constructed using the teachings described above. For example, as shown in
Referring to
The system 100 in
Referring to
The various embodiments described herein all form a means to accelerate a fluid flow without the need for devices having moving parts. The various embodiments disclosed herein thus enable even more reliable, lighter weight, and potentially less costly flow accelerating systems to be implemented than what would be possible with previously developed pumps that require moving parts for their operation.
While various embodiments have been described, those skilled in the art will recognize modifications or variations which might be made without departing from the present disclosure. The examples illustrate the various embodiments and are not intended to limit the present disclosure. Therefore, the description and claims should be interpreted liberally with only such limitation as is necessary in view of the pertinent prior art.