Self-excitation rotational flow generating device based on jet flow oscillator

Abstract

The invention provides a self-excited rotational flow generating device based on jet flow oscillators, which comprises a hollow mandrel, a first part jet flow oscillator and at least one second part jet flow oscillator, the first part jet flow oscillator comprises a first part inlet chamber, a first part oscillation cavity, a first part outlet chamber and two feedback channels used for enabling fluid to generate continuous oscillation. The second part jet flow oscillator comprises a second part inlet chamber, a second part oscillation cavity, a second part outlet chamber and two feedback channels used for enabling fluid to generate continuous oscillation, and the first part inlet chamber and the second part inlet chamber jointly form a main flow distribution chamber; the first part oscillation cavity and the second part oscillation cavity jointly form a main oscillation chamber, and the first part outlet chamber and the second part outlet chamber jointly form a jet flow outlet. According to the invention, no active moving part is arranged, no extra energy input is needed, and strong-swirl shearing motion can be generated near a jet outlet to generate swirl through self-excitation.

Description

Technical Field

[0001] The invention relates to the technical field of fluid jet control, and is a self-excited swirl flow generating device based on a jet oscillator. Background Art

[0002] The jet oscillator is a special structure that can complete the periodic motion of the fluid only by its own structure without the help of a power input device. According to the working principle of the jet oscillator, it can usually be divided into a load-type oscillator, a feedback oscillator, a sonic oscillator and a resonance oscillator. For the feedback oscillator, when the jet enters the main chamber of the device through the inlet nozzle, a Coanda effect will occur, and the main stream will flow on the near wall surface. Due to the flow limiting effect of the outlet nozzle, the main jet will eventually pass through the nozzle outlet at a certain angle, and part of the fluid will be diverted to the feedback channel. Through the reflux into the control roar, a growing recirculation separation bubble is generated, thereby pushing the main stream to another feedback channel. This process is repeated, forming a sweeping oscillating jet at the nozzle.

[0003] With the continuous development of jet research, the active flow control function of jet oscillators in the fields of fluid machinery and aviation has been gradually discovered. Due to the simple structure and stable operation of jet oscillators, they are widely used in the fluid field. For example, in the fields of petrochemicals, they are often used as flow control and fluid generators. At the same time, due to the sweeping characteristics of the jet, jet oscillators are often used in pneumatic generating devices, which can improve the aerodynamic performance of various designs and achieve effective separation control.

[0004] The basic principle of existing swirl generating devices is that fluids are separated under the action of centrifugal force, and multiphase fluids are tangentially directed to the cyclone at a certain pressure to generate a high-speed rotating flow field in the cylindrical cavity. Due to the different movement directions of fluids with different densities, external and internal vortices are generated in the cavity, thereby achieving the purpose of multiphase separation. These swirl generating devices require additional electrical energy, have complex structures, and have many vulnerable parts, and have limited service life in complex environments. Summary of the invention

[0005] The present invention provides a self-excited swirl flow generating device based on a jet oscillator, the purpose of which is to solve the problems in the prior art that the generation of swirl flow requires the use of motor functions and the structure is complex and has many vulnerable parts.

[0006] The technical solution adopted by the present invention to solve the above-mentioned technical problems is: a self-excited swirl flow generating device based on a jet oscillator, comprising a hollow core shaft, a first part jet oscillator and at least one second part jet oscillator, the first part jet oscillator comprising a first part inlet chamber, a first part oscillation cavity, a first part outlet chamber and two feedback channels for causing the fluid to produce continuous oscillations, the second part jet oscillator comprising a second part inlet chamber, a second part oscillation cavity, a second part outlet chamber and two feedback channels for causing the fluid to produce continuous oscillations, the first part inlet chamber and the second part inlet chamber together constitute a mainstream diversion chamber, the first part oscillation cavity and the second part oscillation cavity together constitute a main oscillation chamber, and the first part outlet chamber and the second part outlet chamber together constitute a jet outlet.

[0007] Furthermore, the spindle is a rotating hollow spindle.

[0008] Furthermore, the jet oscillators are cross-distributed.

[0009] Furthermore, the fluidic oscillator is a dual-feedback channel type fluidic oscillator.

[0010] Furthermore, the first part of the fluidic oscillator and the second part of the fluidic oscillator have the same structural size.

[0011] Furthermore, the jet oscillators share a main flow diversion chamber, the jet oscillators share a main oscillation chamber, and the jet oscillators share an outlet.

[0012] Furthermore, the length of the jet oscillator is L1, the width of the jet oscillator is D1, and the aspect ratio of the jet oscillator is n1=L1 / D1, wherein 1≤n1≤1.5.

[0013] Furthermore, the axial angle between the jet outlet wall and the inlet is not less than 45°.

[0014] Furthermore, the jet oscillators have the same oscillation frequency.

[0015] The above scheme of the present invention has the following beneficial effects:

[0016] The present invention has no active moving parts and does not require additional energy input. It can self-excite and generate swirl only by relying on the internal fluid channel setting. The swirl frequency and swirl intensity can be adjusted by changing the flow rate of the steady flow and the number of jet oscillators. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic structural diagram of a self-excited swirling flow generating device based on a jet oscillator according to an embodiment of the present invention;

[0018] Figure 2 It is a schematic structural diagram of a fluidic oscillator 4 according to an embodiment of the present invention;

[0019] Figure 3 A schematic diagram of a fluid flow path according to an embodiment of the present invention;

[0020] In the figure: 1-inlet; 2-hollow core shaft; 3-first part jet oscillator; 4-second part jet oscillator; 5-first feedback wall plate; 6-second feedback wall plate; 7-first feedback channel; 8-second feedback channel; 9-third feedback wall plate; 10-fourth feedback wall plate; 11-third feedback channel; 12-fourth feedback channel; 13-main stream diversion chamber; 14-main oscillation chamber; 15-jet outlet; 16-jet outlet wall. DETAILED DESCRIPTION

[0021] In order to make the technical problems, technical solutions and advantages to be solved by the present invention more clear, a detailed description will be given below with reference to the accompanying drawings and specific embodiments.

[0022] In view of the problems in the prior art that the generation of swirl flow requires the use of motor functions and has a complex structure with many vulnerable parts, the present invention provides a self-excited swirl flow generating device based on a jet oscillator.

[0023] Reference Figure 1 and Figure 2 An embodiment of the present invention provides a self-excited swirling flow generating device based on a jet oscillator, comprising a hollow mandrel 2 connected to an inlet 1, a first part jet oscillator 3 and a second part jet oscillator 4 connected to the hollow mandrel 2, the jet oscillator 3 comprising a first feedback wall plate 5, a second feedback wall plate 6, a first feedback channel 7, and a second feedback channel 8, the jet oscillator 4 comprising a third feedback wall plate 9, a fourth feedback wall plate 10, a third feedback channel 11, and a fourth feedback channel 12, the first part jet oscillator 3 and the second part jet oscillator 4 share a mainstream diversion chamber 13, the first part jet oscillator 3 and the second part jet oscillator 4 share a main oscillation chamber 14, and the first part jet oscillator 3 and the second part jet oscillator 4 share a jet outlet 15.

[0024] This embodiment combines two identical jet oscillators to form a self-excited swirl flow generating device. Through the interaction of the internal fluids of the present invention, the direction of the outlet jet velocity changes periodically, forming a swirl flow under the action of the radial deflection force.

[0025] In this embodiment, the axial angle between the jet outlet wall 16 and the inlet 1 is not less than 45°. Experiments have shown that the jet oscillator has good stability, a large sweep angle, and is more likely to produce large-amplitude oscillations. The aspect ratio of the first part jet oscillator 3 and the second part jet oscillator 4 is not less than 1 and not more than 1.5, which reduces the momentum loss of the mainstream. Experiments have shown that the oscillation effect is good and it is easier to produce high-frequency oscillations.

[0026] Reference Figure 1 and Figure 3 The working principle of the present invention is as follows: after the steady flow enters the mainstream flow diversion chamber 13 from the inlet 1 through the hollow mandrel 2, the flow is evenly distributed to the first part of the jet oscillator 3 and the second part of the jet oscillator 4. Based on the Coanda effect, the fluid of the jet oscillator 3 will adhere to one of the first feedback wall plate 5 or the second feedback wall plate 6. When the fluid adheres to the first feedback wall plate 5, due to the flow limiting effect of the jet outlet 15, part of the fluid flows back into the first feedback channel 7, resulting in an increase in pressure on the side of the first part of the jet oscillator 3 near the first feedback wall plate 5, and the lateral disturbance of the jet generates a A separation bubble is formed to push the mainstream to switch to the other side. After the jet direction is switched, the same phenomenon occurs on the side of the first part jet oscillator 3 near the second feedback wall plate 6, and the self-excited oscillation behavior is maintained. The mainstream alternately leaves the jet outlet 15 to form an oscillating jet in the radial direction. Similarly, the second part jet oscillator 4 forms an oscillating jet in the radial direction. The first part jet oscillator 3 and the second part jet oscillator 4 form oscillating jets in different radial directions, respectively. This cycle generates a radial deflection force to drive the hollow core shaft 2 to rotate, thereby causing the jet velocity direction of the jet outlet 15 to change periodically, thereby realizing the self-excitation of the swirl.

[0027] Although the above content describes the embodiments of the present invention in conjunction with the accompanying drawings, the present invention is not limited to the above-mentioned specific implementation methods. The above-mentioned specific implementation methods are merely illustrative and not restrictive. For technical personnel in the relevant field, other changes or modifications can be made on the basis of the above disclosure, and these changes or modifications are still within the scope of the present disclosure.

Claims

1. A self-excited swirl flow generating device based on a jet oscillator, characterized in that: It includes a hollow core shaft, a first-part jet oscillator and at least one second-part jet oscillator, wherein the first-part jet oscillator includes a first-part inlet chamber, a first-part oscillation cavity, a first-part outlet chamber and two feedback channels for causing the fluid to oscillate continuously, and the second-part jet oscillator includes a second-part inlet chamber, a second-part oscillation cavity, a second-part outlet chamber and two feedback channels for causing the fluid to oscillate continuously.

2. The self-excited swirling flow generating device based on a jet oscillator according to claim 1, characterized in that: The first part of the fluidic oscillators and the second part of the fluidic oscillators are cross-distributed.

3. The self-excited swirling flow generating device based on a jet oscillator according to claim 1, characterized in that: The fluidic oscillator is a dual-feedback channel type fluidic oscillator.

4. The self-excited swirling flow generating device based on a jet oscillator according to claim 1, characterized in that: The first partial fluidic oscillator and the second partial fluidic oscillator have the same structural dimensions.

5. The self-excited swirling flow generating device based on a jet oscillator according to claim 1, characterized in that: The first portion inlet chamber and the second portion inlet chamber together form a mainstream flow diversion chamber.

6. The self-excited swirling flow generating device based on a jet oscillator according to claim 1, characterized in that: The first partial oscillation cavity and the second partial oscillation cavity together form a main oscillation chamber.

7. The self-excited swirling flow generating device based on a jet oscillator according to claim 1, characterized in that: The first partial outlet chamber and the second partial outlet chamber together form a jet outlet.

8. The self-excited swirling flow generating device based on a jet oscillator according to claim 1, characterized in that: The aspect ratio of the feedback channel is not less than 1 and not more than 1.

5.

9. The self-excited swirling flow generating device based on a jet oscillator according to claim 1, characterized in that: The axial angle between the jet outlet wall and the inlet is not less than 45°.

Images