A stable flow-equalizing jet oscillator

Abstract

This invention belongs to the field of pressure fluid jet control and distribution, and gas pulse expansion refrigeration technology. It relates to a stable flow-equalizing jet oscillator, a special device required for gas distribution and gas refrigeration. This invention achieves mixing and periodic wall-attached oscillation of two jets within the oscillation chamber of the oscillator by periodically and alternately applying external excitation flow rates at two excitation ports. This results in more uniform flow rates and duty cycles at downstream outlets, with pulsed jets of corresponding oscillation frequencies. This invention has no moving parts, is simple to manufacture, has low cost, is reliable and stable in operation, and has strong adaptability to various working conditions. It can be used in applications such as high-pressure gas jet pulses, oscillations, jet control, and distribution.

Description

Technical Field

[0001] This invention relates to the fields of pressure fluid jet control and distribution, and gas pulse expansion refrigeration technology, and in particular to a stable flow equalization jet oscillator. Background Technology

[0002] When fluid is propelled by a pressure difference or external boundary force, it is ejected into space in a bundle form from a relatively narrow open opening such as a nozzle, pipe, or slit, forming a jet. Pulsed jets, which are obtained by controlling the direction of the jet or by generating pulsations, have a wide range of engineering applications, such as cleaning, dust removal, absorption and adsorption of gases in a medium layer, and gas wave refrigeration, etc.

[0003] By utilizing the Coanda effect of the jet, the flow direction of the jet can be periodically controlled to deliver it to different branch pipes or downstream devices, achieving pulsed flow and flow distribution of fluid in a downstream branch. Chinese patents ZL200810011575.1, ZL200810011576.2, and ZL201610939832.9 are examples of jet oscillators implemented using the Coanda effect for different purposes.

[0004] However, for applications such as refrigeration and jetting, to achieve the required high efficiency, short pulses with small duty cycles are often necessary. This necessitates delivering the jet into multiple channels in turn. However, simply arranging the downstream channels receiving the pulsed jet side-by-side or in a fan shape results in the jet's wall adhesion time being much longer than its rotation time due to the Coanda effect. This leads to extremely uneven distribution of the jet flow rate in each branch channel, which cannot meet the application requirements.

[0005] Chinese patent ZL201410484604.8 uses a multi-stage oscillation method to allow the pulse jet in the branch to generate one (or more) wall-attached oscillations, generating a second (or N) branch distribution, thus producing 2N pulse jet branches; patent ZL201610045338.8 uses a spatial arrangement of branch channels, in which the jet is distributed to at least 4 branch channels in a three-dimensional wall-attached oscillation manner.

[0006] However, multi-stage oscillations have high requirements for excitation, and the structure of three-dimensional oscillations is relatively complex. Although planar fan-shaped oscillators are simple, the jet flow is unevenly distributed. Therefore, it is necessary to innovate new types of jet oscillators with more comprehensive advantages. Summary of the Invention

[0007] To address the aforementioned issues, a stable flow-equalizing jet oscillator is proposed. This jet oscillator features a simple structure, no moving parts, reliable operation, controllable oscillation frequency, and a simple and easy excitation method. Furthermore, the multi-pulse jet flow generated is significantly more uniform and stable than that of conventional fan-shaped pulse oscillators.

[0008] To achieve the above objectives, the technical solution adopted by the present invention is as follows:

[0009] A stable flow equalization jet oscillator includes an oscillator body and a top cover covering one side surface of the flow channel of the oscillator body. The surface of the oscillator body facing the top cover has flow channels, which include two main jet inlet flow channels, two excitation jet inlet flow channels, two main jet wall-attached flow channels, a deflection mixing chamber, and at least two outlet gas flow channels.

[0010] The deflection mixing cavity is located in the middle of the oscillator body, and the two main jet inlet channels, the two excitation jet inlet channels, and the two main jet wall-attached channels are respectively located on both sides of the central axis of the deflection mixing cavity;

[0011] The output end of the main jet inlet section is connected to the output end of the excitation jet inlet section and the input end of the main jet wall-attached section. The output end of the main jet wall-attached section is connected to the input side of the deflection mixing chamber, and the output side of the deflection mixing chamber is connected to the input side of the outlet gas flow channel.

[0012] Preferably, the main jet inlet channel, the excitation jet inlet channel, the main jet wall-attached channel, and the multiple outlet gas channels are symmetrically distributed around the central axis of the deflection mixing chamber.

[0013] Preferably, the axis of the main jet inlet section and the axis of the main jet wall-attached section both form an inwardly recessed angle with the central axis of the deflection and merging cavity along the airflow direction, with each angle ranging from 1 to 70°.

[0014] Preferably, the axis of the outlet gas flow channel forms a diverging angle with the central axis of the deflection and merging cavity, and the diverging angle of the axis of the outlet gas flow channel farther from the central axis of the deflection and merging cavity is greater than the diverging angle of the axis of the outlet gas flow channel closer to the central axis of the deflection and merging cavity, so that multiple outlet gas flow channels form a fan-shaped extended flow channel group.

[0015] Preferably, the flow channel is a grooved flow channel machined by mechanical cutting, and the cross-section of the flow channel is rectangular or trapezoidal, with the width-to-depth ratio of the flow channel between 1:0.5 and 1:7.

[0016] Preferably, the processing method of the outlet gas flow channel is as follows: a fan-shaped groove is processed on the oscillator body, and then multiple long strips or trapezoidal blocks are welded in the fan groove, forming outlet gas flow channels between the blocks.

[0017] Preferably, the open profile of the main jet inlet section flow channel on the inner plane of the oscillator body is a short, straight shape with a gradually narrowing shape, and the transition between the main jet inlet section flow channel and the main jet attached wall section flow channel is an abrupt expansion transition.

[0018] The front section of the main jet wall-attached section is a short straight straight channel, and the rear section of the main jet wall-attached section is an expanding channel. The aspect ratio of the front straight straight channel of the main jet wall-attached section is 0:1 to 3:1. The rear expanding channel of the main jet wall-attached section is connected to the deflection mixing cavity, and the expansion angle of the expanding channel is 1 to 60°.

[0019] Preferably, the outlet opening of the excitation jet inlet section is located on the outer wall of the corresponding main jet attached section, and the angle between the axes of the excitation jet inlet section and the main jet attached section on the same side is in the range of 30° to 120°.

[0020] Preferably, the input end of the excitation jet inlet channel is connected to the output end of an external small dual-tube self-excited jet oscillator to obtain an excitation jet with a certain frequency and duty cycle.

[0021] The beneficial effects of using this invention are:

[0022] In this jet oscillator, due to the coupling mechanism of the two jets, the angular velocity of its wall-attached oscillation is lower than that of a single jet, and the wall-attached time is shorter than that of a single jet, thereby improving the non-uniformity of the pulse jet in each outlet gas channel. Attached Figure Description

[0023] Figure 1 This is a three-dimensional schematic diagram of the stable flow-equalizing jet oscillator of the present invention.

[0024] Figure 2 This is a front cross-sectional view of the stable flow-equalizing jet oscillator of the present invention.

[0025] Figure 3 This is a schematic diagram of the oscillation principle of the stable flow-equalizing jet oscillator of the present invention.

[0026] Figure 4 This is a schematic diagram of an intake waveform for an excited jet, where the solid line represents the intake stage of the excited jet.

[0027] In the figure: 1- First main jet inlet section flow channel, second main jet inlet section flow channel, 3- First excitation jet inlet section flow channel, 4- Second excitation jet inlet section flow channel, 5- First main jet wall-attached section flow channel, 6- Second main jet wall-attached section flow channel, 7- Deflection mixing chamber, 8- Outlet gas flow channel, 9- Oscillator body. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this technical solution clearer, the following detailed description, in conjunction with specific embodiments, further illustrates this technical solution. It should be understood that these descriptions are merely exemplary and not intended to limit the scope of this technical solution.

[0029] like Figure 1 As shown in Figure 3, this embodiment proposes a stable flow-equalizing jet oscillator, including an oscillator body 9 and a top cover covering one side of the flow channel of the oscillator body 9. The surface of the oscillator body 9 facing the top cover has flow channels, including two main jet inlet flow channels, two excitation jet inlet flow channels, two main jet wall-attached flow channels, a deflection mixing cavity 7, and at least two outlet gas flow channels 8. The deflection mixing cavity 7 is located in the middle of the oscillator body 9, and the two main jet inlet flow channels, the two excitation jet inlet flow channels, and the two main jet wall-attached flow channels are respectively located on both sides of the central axis of the deflection mixing cavity 7. The output end of the main jet inlet flow channel is connected to the output end of the excitation jet inlet flow channel and the input end of the main jet wall-attached flow channel, respectively. The output end of the main jet wall-attached flow channel is connected to the input side of the deflection mixing cavity 7, and the output side of the deflection mixing cavity 7 is connected to the input side of the outlet gas flow channel 8.

[0030] like Figure 1 and Figure 2 As shown, specifically, the main body of this jet oscillator consists of two parts: the oscillator body 9 and the upper cover. Gas flow channels are machined into the inner plane of the oscillator body 9, and the upper cover tightly seals the side boundaries of the gas channels. The gas flow channels include a first main jet inlet channel 1 on the left and a second main jet inlet channel 2 on the right. The first main jet inlet channel 1 and the second main jet inlet channel 2 divide the main jet into two streams that enter the oscillator. The first excitation jet inlet channel 3 on the left and the second excitation jet inlet channel 4 on the right are used to excite the jet into the oscillator. Following this... The first main jet wall-attached channel 5 is located on the left and the second main jet wall-attached channel 6 is located on the right. The first main jet wall-attached channel 5 and the second main jet wall-attached channel 6 are used to introduce the excitation jet and the main jet into the confluence cavity 7. The outlet gas channel 8 is used as the pulse jet output and there are 2 to 10 channels. The first main jet inlet channel 1, the second main jet inlet channel 2, the first excitation jet inlet channel 3, the second excitation jet inlet channel 4, the first main jet wall-attached channel 5 and the second main jet wall-attached channel 6 are all located in front of the deflection confluence cavity, i.e., upstream. The outlet gas channel is located behind the deflection confluence cavity, i.e., downstream.

[0031] The main jet inlet channel, the excitation jet inlet channel, the main jet wall-attached channel, and multiple outlet gas channels 8 are all symmetrically distributed around the central axis of the deflection mixing chamber 7. In this embodiment, the first main jet inlet channel 1 and the second main jet inlet channel 2, the first excitation jet inlet channel 3 and the second excitation jet inlet channel 4, the first main jet wall-attached channel 5 and the second main jet wall-attached channel 6 are all symmetrically distributed around the central axis of the deflection mixing chamber 7. The outlet gas channels 8 are also symmetrically distributed around the central axis of the deflection mixing chamber 7.

[0032] The axes of the main jet inlet section and the main jet wall section both form an inwardly converging angle with the central axis of the deflection and merging cavity along the airflow direction. The angles range from 1° to 70°, such as 5°, 10°, 15°, 20°, 25°, 30°, 35°, 40°, 50°, and 60°.

[0033] The present invention provides a stable flow equalization jet oscillator, which has 2 to 10 outlet gas channels 8 for pulse jet output. Each of these channels has a certain divergence angle with the central axis of the deflection and merging cavity. The outer channel that is further away from the central axis of the merging cavity has a larger divergence angle, thus forming a fan-shaped extended channel group.

[0034] The flow channel is machined into a grooved shape by mechanical cutting. The cross-section of the flow channel is rectangular or trapezoidal, and the width-to-depth ratio of the flow channel is between 1:0.5 and 1:7.

[0035] The processing method of the outlet gas flow channel 8 is as follows: a fan-shaped groove is processed on the oscillator body 9, and then multiple long strips or trapezoidal blocks are welded in the fan groove, forming outlet gas flow channels 8 between the blocks.

[0036] The open profile of the main jet inlet section flow channel on the inner plane of the oscillator body 9 is a gradually narrowing short and straight shape, and the transition between the main jet inlet section flow channel and the main jet attached wall section flow channel is abruptly widened.

[0037] The front section of the main jet wall-attached section is a short straight straight channel, and the rear section of the main jet wall-attached section is an expanding channel. The aspect ratio of the front straight straight channel of the main jet wall-attached section is 0:1 to 3:1. The rear expanding channel of the main jet wall-attached section is connected to the deflection mixing chamber 7, and the expansion angle of the expanding channel is 1 to 60°.

[0038] The outlet opening of the excitation jet inlet section is located on the outer wall of the corresponding main jet attached section, and the angle between the axes of the excitation jet inlet section and the main jet attached section on the same side is 30° to 120°.

[0039] The input end of the excitation jet inlet channel is connected to the output end of an external small dual-tube self-excited jet oscillator to obtain an excitation jet with a certain frequency and duty cycle.

[0040] like Figure 3 As shown, when an unexcited jet enters, pressurized gas is simultaneously injected into the first main jet inlet channel 1 and the second main jet inlet channel 2, forming two high-speed continuous jets. Then, at the junction of the first main jet inlet channel 1 and the second main jet inlet channel 2 with the first main jet wall-attached channel 5 and the second main jet wall-attached channel 6, the jet detaches from the wall. Due to geometric deviation and the randomness of the flow, the Coanda effect causes the jet to initially attach to the wall. When the jet flows into the deflection and merging cavity 7 of the two jets, the two jets couple with each other and maintain a balanced state deflected to one side. At this time, a pulsed excitation jet enters the first main jet wall-attached section 5 or the second main jet wall-attached section 6 through the outer opening of the first main jet wall-attached section 5 or the second main jet wall-attached section 6. If the main jet is attached to the inner side of this channel at this time, the excitation flow strengthens the wall attachment and further deflects the converging jet in the two jets deflection confluence cavity 7. If the main jet is attached to the outer side of the channel at this time, or if the opposite main jet is excited in the next half-cycle, the main jet detaches from the wall and deflects to the other side. When it flows back into the two jets deflection confluence cavity 7, the coupling effect causes the confluenced jet to deflect in the opposite direction. Its periodic variation is as follows: Figure 4 As shown, as the excitation flow continuously switches left and right and flows into the first main jet wall section 5 or the second main jet wall section 6, the aforementioned converging jets are continuously deflected, resulting in a fan-shaped oscillating oscillation corresponding to the frequency of the excitation pulse flow. The continuously distributed converging jets enter multiple outlet gas channels 8, thereby generating multiple pulse jets.

[0041] The above content is only a preferred embodiment of the present invention. For those skilled in the art, many changes can be made in the specific implementation and application scope based on the ideas of the present invention. As long as these changes do not depart from the concept of the present invention, they all fall within the protection scope of this patent.

Claims

1. A stable flow-equalizing jet oscillator, comprising an oscillator body and a top cover covering one side surface of the flow channel of the oscillator body, wherein the surface of the oscillator body facing the top cover has a flow channel, characterized in that: The flow channel includes two main jet inlet flow channels, two excitation jet inlet flow channels, two main jet wall-attached flow channels, a deflection mixing chamber, and at least two outlet gas flow channels; The deflection mixing cavity is located in the middle of the oscillator body, and the two main jet inlet channels, the two excitation jet inlet channels, and the two main jet wall-attached channels are respectively located on both sides of the central axis of the deflection mixing cavity; The output end of the main jet inlet section is connected to the output end of the excitation jet inlet section and is connected to the input end of the main jet wall-attached section. The output end of the main jet wall-attached section is connected to the input side of the deflection mixing chamber, and the output side of the deflection mixing chamber is connected to the input side of the outlet gas flow channel. The open profile of the main jet inlet section flow channel on the inner plane of the oscillator body is a gradually narrowing short and straight shape, and the transition between the main jet inlet section flow channel and the main jet attached wall section flow channel is an abrupt expansion transition. The front section of the main jet wall-attached section is a short straight straight channel, and the rear section of the main jet wall-attached section is an expanding channel. The aspect ratio of the front straight straight channel of the main jet wall-attached section is 0:1 to 3:

1. The rear expanding channel of the main jet wall-attached section is connected to the deflection mixing cavity, and the expansion angle of the expanding channel is 1 to 60°.

2. The stable current-sharing jet oscillator according to claim 1, characterized in that: The main jet inlet channel, the excitation jet inlet channel, the main jet wall-attached channel, and multiple outlet gas channels are symmetrically distributed around the central axis of the deflection mixing chamber.

3. The stable current-equalizing jet oscillator according to claim 1, characterized in that: The axis of the main jet inlet section and the axis of the main jet wall section both form an inwardly recessed angle with the central axis of the deflection and merging cavity along the airflow direction, with each angle ranging from 1 to 70°.

4. The stable current-sharing jet oscillator according to any one of claims 1-3, characterized in that: The axis of the outlet gas flow channel forms a diverging angle with the central axis of the deflection and merging cavity, and the diverging angle of the axis of the outlet gas flow channel farther from the central axis of the deflection and merging cavity is greater than the diverging angle of the axis of the outlet gas flow channel closer to the central axis of the deflection and merging cavity, so that multiple outlet gas flow channels form a fan-shaped extended flow channel group.

5. The stable flow-sharing jet oscillator according to any one of claims 1-3, characterized in that: The flow channel is a grooved flow channel machined by mechanical cutting. The cross-section of the flow channel is rectangular or trapezoidal, and the width-to-depth ratio of the flow channel is between 1:0.5 and 1:

7.

6. The stable current-sharing jet oscillator according to any one of claims 1-3, characterized in that: The processing method of the outlet gas flow channel is as follows: a fan-shaped groove is processed on the oscillator body, and then multiple long strips or trapezoidal blocks are welded in the fan groove, forming outlet gas flow channels between the blocks.

7. The stable current-sharing jet oscillator according to claim 1, characterized in that: The outlet opening of the excitation jet inlet section is located on the outer wall of the corresponding main jet attached section, and the angle between the axes of the excitation jet inlet section and the main jet attached section on the same side is 30° to 120°.

8. The stable current-sharing jet oscillator according to claim 1, characterized in that: The input end of the excitation jet inlet channel is connected to the output end of an external small dual-tube self-excited jet oscillator to obtain an excitation jet with a certain frequency and duty cycle.

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