A reinforced atomizing centrifugal nozzle structure and method

Abstract

The application discloses a centrifugal nozzle structure and method for strengthening atomization, and belongs to the technical field of liquid atomization. The centrifugal nozzle structure comprises a rotating flow chamber and a nozzle, and the innovation is that at least one micro-rib structure is arranged on the inner wall surface of the rotating flow chamber. The radial height of the micro-rib structure is designed to be in the same order of magnitude (preferably 50-150 microns) as the wall boundary layer thickness of the liquid film in the rotating flow chamber, so that it can precisely disturb the boundary layer fluid close to the wall, and hardly affect the high-speed rotating main flow. The micro-rib can be an axial straight strip or a small helix angle helix. During work, the micro-rib breaks the laminar flow state of the boundary layer, promotes circumferential mixing, implants controllable micro-unstable waves, so that the liquid film is more uniform and controllable broken at the nozzle, and the atomization quality (such as reducing the Sauter mean diameter and stabilizing the atomization cone angle) is significantly improved, while the flow resistance is hardly increased, and the flow coefficient is not affected. The application has the advantages of simple structure and strong robustness, and is suitable for fuel atomization in the fields of aeroengines, gas turbines and the like.

Description

Technical Field

[0001] This invention relates to the field of liquid atomization technology, specifically to a centrifugal fuel nozzle (or swirl nozzle), and particularly to an enhanced atomization centrifugal nozzle structure and method that improves the initial atomization quality by setting micro-rib structures of specific sizes on the wall of the swirl chamber to finely control the boundary layer flow. Background Technology

[0002] Centrifugal fuel nozzles are key components widely used in modern gas turbines and aircraft engines. Their working principle involves fuel entering the swirl chamber through a tangential inlet, forming a high-speed rotating liquid film, which is then ejected from the nozzle and broken into droplets by centrifugal force and interaction with air.

[0003] The core of atomization quality lies in the stability and uniformity of the liquid film at the moment of exiting the nozzle. However, in practice, due to factors such as machining precision and inherent flow instability, the liquid film in the vortex chamber, especially in the boundary layer region close to the wall, may exhibit microscopic inhomogeneities. These inhomogeneities are amplified when the liquid film accelerates away from the nozzle, leading to problems such as liquid film tearing, atomization angle fluctuations, increased Sothel average diameter, and wider distribution.

[0004] Traditional methods for improving atomization quality often focus on optimizing the macroscopic geometric parameters of the swirl chamber and nozzle. Some approaches propose incorporating large radial bosses or turbulence ribs within the swirl chamber to disrupt the swirl structure. However, such large radial turbulence structures significantly increase flow resistance, leading to a decrease in the flow coefficient. Furthermore, they may excessively disturb the mainstream, generating uncontrollable large-scale vortex structures, which in turn worsens the liquid film condition and increases susceptibility to wear and cavitation, thus affecting nozzle lifespan.

[0005] Therefore, existing technologies lack an effective method for precisely controlling the flow at the bottom of the liquid film while having minimal impact on the mainstream. The purpose of this invention is to solve the above-mentioned problems. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing centrifugal nozzle technology, such as insufficient control of the flow at the bottom layer of the swirling liquid film, and the large resistance and rough effect of traditional turbulence structures. It provides a centrifugal nozzle structure and method that can achieve "precise control" of the boundary layer and significantly improve atomization quality without significantly affecting the flow coefficient.

[0007] The technical solution of this invention is implemented as follows: In a first aspect, the present invention provides a centrifugal nozzle structure for enhanced atomization, comprising a swirling chamber and a nozzle, wherein the swirling chamber is provided with a tangential inlet, characterized in that: at least one microrib structure for disturbing the wall boundary layer fluid is provided on the inner wall surface of the swirling chamber, wherein the radial height of the microrib structure is on the same order of magnitude as the wall boundary layer thickness of the liquid film inside the swirling chamber, such that the microrib structure mainly acts on the wall boundary layer, while having minimal impact on the main swirling flow.

[0008] As a further technical solution of the present invention: the microrib structure is a straight strip-shaped microrib extending along the axial direction of the swirl chamber, or a spiral-shaped microrib with a helix angle of less than 15°.

[0009] As a further technical solution of the present invention: the radial height of the microrib structure is 50 micrometers to 150 micrometers.

[0010] As a further technical solution of the present invention: the microrib structure is circumferentially evenly distributed on the wall surface of the cyclone chamber; or, the microrib structure is non-uniformly distributed with denser density in a specific area on the wall surface of the cyclone chamber.

[0011] As a further technical solution of the present invention: the top surface morphology of the microrib structure is at least one of stepped, wavy or serrated.

[0012] As a further technical solution of the present invention: the radial height of the microrib structure gradually changes along the axial direction of the swirl chamber, and its height gradually decreases or increases from the inlet end of the swirl chamber to the nozzle end.

[0013] As a further technical solution of the present invention: the microrib structure is integrated on an independent, detachable swirl chamber bushing, and the bushing is fitted inside the swirl chamber.

[0014] Secondly, the present invention provides a method for enhancing the atomization effect of a centrifugal nozzle using a micro-rib structure, comprising the following steps: The fuel is drawn from the tangential inlet into the swirling chamber of the centrifugal nozzle, forming a high-speed rotating liquid film; By using microrib structures set on the inner wall of the swirl chamber, the liquid film boundary layer fluid closely attached to the wall is finely disturbed. The radial height of the microrib structure is on the same order of magnitude as the wall boundary layer thickness of the liquid film. The perturbation of the microrib structure promotes circumferential mixing of the fluid within the boundary layer, making the liquid film thickness distribution more uniform, and implanting controllable micro unstable waves within the boundary layer. The liquid film, disturbed by the micro-rib structure, is ejected from the nozzle, and under the action of the tiny unstable wave, more uniform and controllable atomization is achieved.

[0015] As a further technical solution of the present invention: the disturbance of the microrib structure causes the bottom layer of the liquid film to transition from a laminar or quasi-laminar state to a weakly turbulent state in advance.

[0016] As a further technical solution of the present invention: for fuels of different viscosities, the microrib structure with different macroscopic geometric shapes is adopted; wherein, for high viscosity fuel, low and wide weir-shaped microribs are adopted; for low viscosity fuel, tall and slender wing-shaped microribs are adopted.

[0017] Compared with the prior art, the beneficial effects of the present invention are as follows: 1. Precise control: The disturbance target is precisely located to the wall boundary layer that determines the stability of the liquid film, realizing the leap from "coarse intervention of the mainstream" to "fine control of the boundary layer", solving the fundamental problem of liquid film uniformity with minimal hydrodynamic cost.

[0018] 2. Significantly improved atomization quality: The homogenized and pre-activated liquid film breaks down more fully and uniformly, which can effectively reduce the Sothel mean diameter (SMD), making the droplet size distribution more concentrated and the atomization cone angle more stable, thereby helping to improve combustion efficiency and reduce pollutant emissions.

[0019] 3. High performance-benefit ratio: The micro-ribs arranged axially or with a small helical angle have extremely low resistance to the mainstream swirling flow. While achieving excellent atomization effect, they have almost no impact on the nozzle flow coefficient, achieving an extremely high "performance-benefit-cost ratio".

[0020] 4. Simple and robust structure: Only micro-ribs need to be machined on the wall of the cyclone chamber or a bushing with micro-ribs is used. There is no need to change the main structure of the nozzle, no increase in moving parts, and the increase in processing cost is limited. It also avoids the wear and cavitation problems caused by large radial turbulence structures and has good durability.

[0021] The present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of a traditional centrifugal nozzle structure.

[0023] Figure 2 This is a schematic diagram of a centrifugal nozzle (vortex vane type) with axial straight strip-shaped microribs provided in Embodiment 1 of the present invention.

[0024] Figure 3 This is a schematic diagram of a centrifugal nozzle (vortex type) with axial straight strip-shaped microribs provided in Embodiment 1 of the present invention.

[0025] Figure 4 This is a schematic diagram of a centrifugal nozzle (vortex vane type) with spiral microribs provided in Embodiment 2 of the present invention.

[0026] Figure 5 This is a schematic diagram of a centrifugal nozzle (swirl channel type) with spiral microribs provided in Embodiment 2 of the present invention.

[0027] The following are the labels in the attached diagram: 1-Swirl chamber, 2-Swirl generator (or swirling channel), 3-Nozzle, 4-Inner wall of the swirling chamber, 5-Microrib structure, 6-Oil passage. Detailed Implementation

[0028] To make the objectives, technical solutions, and advantages of this invention clearer, the technical solutions of the embodiments of this invention will be described in more detail below with reference to the accompanying drawings. In the drawings, the same or similar reference numerals denote the same or similar elements or elements having the same or similar functions throughout. The described embodiments are some embodiments of this invention, but not all embodiments.

[0029] The embodiments described below with reference to the accompanying drawings are exemplary and intended to explain the invention, and should not be construed as limiting the invention.

[0030] Based on the embodiments of this invention, all other embodiments obtained by those skilled in the art without inventive effort are within the scope of protection of this invention.

[0031] The following is in conjunction with the appendix Figure 1-5 The embodiments of the present invention will be described in detail below.

[0032] Example 1 This invention discloses a centrifugal nozzle with axial straight strip-shaped microribs.

[0033] Reference Figure 2 and Figure 3 The enhanced atomizing centrifugal nozzle of this embodiment includes a swirl chamber 1, a nozzle 3, and a swirler (vortex vane type) or swirl channel 2 that allows fuel to enter tangentially. The fuel line 6 is used to supply fuel. Figure 1 The key difference from the conventional structure shown is that several straight, axially extending microribs 5 are machined on the cylindrical inner wall 4 of the swirl chamber 1 using techniques such as precision cutting, laser processing, or additive manufacturing. In this embodiment, there are eight microribs 5, evenly distributed circumferentially. The radial height of each microrib 5 is 50 micrometers, and its width is 100 micrometers. This height is comparable to the boundary layer thickness (tens to over one hundred micrometers) of the swirling liquid film near the wall under typical operating conditions, ensuring that its disturbance effect is confined within the boundary layer.

[0034] Working process: Fuel enters the swirling chamber 1 at high speed from the tangential inlet (swirler / slot 2), forming a rotating liquid film. The main core of the liquid film slides over the top of the microribs 5 at high speed with almost no obstruction. However, the boundary layer fluid close to the wall 4 undergoes a subtle change in flow state as it flows through these microribs 5: each microrib 5 generates a slight lift and disturbance to the underlying fluid, generating periodic microscale vortices behind it. These microvortices promote momentum exchange in the circumferential and radial directions within the boundary layer, rapidly "smoothing out" any potential circumferential unevenness in the liquid film thickness. When this "homogenized" and "pre-activated" (i.e., implanted with tiny unstable waves) liquid film reaches the nozzle 3 and expands outward, it is in a more optimized and controllable unstable state, thus breaking into uniform and fine droplets more consistently and rapidly.

[0035] Example 2 This invention discloses a centrifugal nozzle with spiral microribs.

[0036] Reference Figure 4 and Figure 5 The main difference between this embodiment and Embodiment 1 lies in the morphology of the microribs. In this embodiment, the microribs 5 disposed on the inner wall surface 4 of the vortex chamber 1 are helical structures with a helix angle of less than 15°. The radial height of the helical microribs 5 is also on the order of 50-150 micrometers. The helical structure can apply a small axial velocity component to the fluid while disturbing the boundary layer, which helps to guide the flow.

[0037] Its working process is similar to that of Example 1. The spiral microrib 5 also acts precisely on the boundary layer, and promotes the implantation of mixing and unstable waves by generating a more complex three-dimensional microvortex structure, ultimately achieving optimized atomization of the liquid film.

[0038] Other implementation methods: 1. The arrangement of microribs 5 can be uneven, for example, microribs can be densely arranged in circumferential regions where flow separation or excessive liquid film is known to occur.

[0039] 2. The top of the microrib 5 can be processed into a tiny sawtooth or wave shape to introduce a smaller-scale secondary vortex on the basis of the microrib vortex system, further refining the disturbance.

[0040] 3. The height of the microrib 5 can be gradually reduced from the inlet end of the swirl chamber 1 to the nozzle end 3 to match the natural change in the boundary layer thickness during the development of the liquid film.

[0041] 4. All microribs 5 can be fabricated on a single metal or ceramic bushing, which is installed in the cyclone chamber 1 by interference fit or thread, forming a replaceable modular design that facilitates maintenance, upgrades, or fuel changes.

[0042] 5. For high-viscosity biofuels, the microrib 5 can be designed as a low and wide weir shape; for low-viscosity aviation kerosene, it can be designed as a tall and slender wing shape to achieve the optimal disturbance effect on fuel properties.

[0043] Example 3 This invention discloses a centrifugal fuel nozzle with axial or helical microribs on its wall surface. This nozzle induces micro-mixing in advance by finely disturbing the boundary layer of the swirling liquid film, resulting in a more uniform liquid film thickness distribution and better stability. This significantly improves the initial atomization quality without significantly affecting the flow coefficient. It overcomes the shortcomings of existing centrifugal nozzle technology, such as insufficient control over the flow at the bottom layer of the swirling liquid film, high resistance and coarse effects of traditional turbulence structures, and the problem of oil ridges appearing in the spray when burrs or insufficient roughness are present in the oil groove or nozzle.

[0044] Technical solution: A centrifugal fuel nozzle with axial or helical microribs on its wall surface, comprising a swirling chamber and a nozzle, wherein the swirling chamber has a tangential inlet and a cylindrical inner wall surface, characterized in that: On the cylindrical inner wall of the vortex chamber, several low spiral or straight strips are arranged along the axial direction.

[0045] The core design principle of the microribs lies in: Precise targeting: The height of these ribs is precisely designed to be on the order of the wall boundary layer thickness (e.g., tens to hundreds of micrometers). Their purpose is not to impede or alter the mainstream of the vortex, but rather to precisely disturb the lowest-velocity subsurface flow that is closely attached to the wall.

[0046] Unique mechanism of action: (1) Breaking the laminar state: The bottom layer of a high-speed rotating liquid film is prone to "laminarization" or a stable laminar state. Axial or helical micro-ribs can trigger the transition to weak turbulence in advance by periodically and slightly lifting and disturbing this extremely thin fluid layer.

[0047] (2) Promotes circumferential mixing: This micro-perturbation promotes momentum exchange of the liquid film in the thickness direction, making the liquid film velocity and thickness at each point in the circumferential direction tend to be uniform.

[0048] (3) Implanting controllable unstable waves: The ribs introduce micro-vortex structures or surface waves of a specific scale into the boundary layer. These “seeds” develop as the liquid film flows toward the nozzle and accelerates, and eventually cause the liquid film to break in a more uniform and controllable manner when it leaves the nozzle.

[0049] (4) Minimal impact on the main flow: Since the ribs are arranged in an axial or small-angle spiral, their direct obstruction to the circumferential rotating main flow is much smaller than that of any radial protrusion. Therefore, their impact on the flow coefficient and swirling intensity of the nozzle is negligible.

[0050] Key Invention: Axial Microrib Structure of the Cyclone Chamber Wall The cylindrical or conical inner wall of the swirl chamber is equipped with micron-level ribs extending axially, which is fundamentally different from the traditional configuration. This is the core structure of the perturbation boundary layer and the basis for achieving "precise control".

[0051] Two secondary invention points: the specific configuration of spiral and straight micro-ribs.

[0052] The microribs are specifically straight strips or helical structures with a small helical angle (less than 15°). This structure can apply an axial velocity component to the fluid, while the straight strip structure provides axial guidance. These two selectable and specific flow field intervention modes provide structural freedom for optimization under different operating conditions.

[0053] Three secondary inventive points: a constrained structure with micron-level rib height. The radial height of the microribs is strictly limited to 50-150 micrometers. This range is on the same order of magnitude as the boundary layer thickness of the swirling liquid film under typical operating conditions, ensuring that the turbulence acts on the bottom layer of the boundary layer without excessively penetrating into the mainstream region. This is a key parameter for achieving low flow resistance.

[0054] Five key invention points: the arrangement of ribs with uniform or non-uniform circumferential distribution.

[0055] The axial ribs on the swirl chamber wall can be uniformly distributed circumferentially or non-uniformly distributed with increased density in specific areas. Uniform circumferential distribution is suitable for overall optimization, while non-uniform distribution with increased density in specific areas is suitable for targeted enhancement of mixing at specific circumferential locations or for addressing known non-uniform spray problems, providing flexible design flexibility.

[0056] Six key invention points: a composite structure at the top of stepped or wave-shaped ribs.

[0057] The top of the rib (the surface in contact with the fluid) is not planar, but designed as a tiny stepped, wavy, or sawtooth shape. This structure can introduce smaller-scale secondary vortices on the basis of the vortex system generated by the microribs themselves, further refining the disturbance scale and improving mixing efficiency.

[0058] 7 Secondary invention points: Replaceable microribbed cyclone chamber bushing structure.

[0059] The wall surface with axial or helical microribs is not machined directly onto the nozzle body, but is fabricated on a separate, removable swirl chamber bushing, which is connected to the nozzle body by interference fit or thread.

[0060] Eight key invention points: Non-uniform structure with rib height gradually varying along the axial direction. The radial height of the microribs gradually decreases or increases from the inlet end of the swirl chamber to the nozzle end, forming an axial gradient structure. This can match the changes in boundary layer thickness during the development of the liquid film within the swirl chamber, achieving "adaptive" perturbation of the entire flow path and making flow field optimization more global.

[0061] Nine key inventions: Optimization of rib morphology for specific fuels.

[0062] For high-viscosity fuels, such as biofuels, the ribs are low and wide, forming a weir shape; for low-viscosity fuels, such as aviation kerosene, the ribs are tall and slender, forming a wing shape. By designing the macroscopic geometry of the microribs in relation to the physical properties of the fuel (viscosity, surface tension), the core structure can be optimized for specific applications to achieve the best performance.

[0063] Compared with the prior art, the present invention has the following significant advantages: (1) "Precise control" of boundary layer flow was achieved: the disturbance target was precisely located from the "mainstream" to the "boundary layer", realizing a leap from "coarse intervention" to "fine control". By disturbing the bottom layer, which is the key region that determines the stability of the liquid film, the fundamental problem of liquid film uniformity was solved at the lowest cost.

[0064] (2) Significantly improves atomization quality: The liquid film after "homogenization" treatment breaks more fully and uniformly at the nozzle, which can effectively reduce the average diameter of the Sotel, make the droplet size distribution more concentrated, and make the atomization cone angle more stable, thereby promoting combustion efficiency and reducing pollutant emissions.

[0065] (3) “Small disturbance, big effect”, the influence of flow coefficient is negligible: the resistance of the axial or spiral arrangement of micro ribs to the mainstream swirling flow is minimized, achieving excellent atomization effect while almost without sacrificing the flow characteristics of the nozzle. This is an extremely high “performance-benefit-cost ratio”.

[0066] (4) Simple structure and strong robustness: This scheme only requires the machining of fine ribs on the wall of the swirl chamber. It does not require changing the overall structure of the nozzle, does not add moving parts, and the machining cost increases very little. It also has good durability. It successfully avoids all the drawbacks of setting large radial protrusions or turbulence ribs in the swirl chamber.

[0067] Example 4 Reference Figures 2 to 3The centrifugal nozzle of this invention has a cylindrical inner wall 4 in its swirling chamber 1. On this wall 4, eight rectangular cross-section microribs 5 extending axially are machined using precision cutting or additive manufacturing techniques. The ribs are 50 micrometers high and 100 micrometers wide; their height is much smaller than the radius of the swirling chamber, only on the order of the liquid film boundary layer thickness.

[0068] Work process: Fuel enters the vortex chamber 1 at high speed from the tangential inlet 2, forming a rotating liquid film. The main body of the liquid film slides at high speed over the tips of the microribs 5 with almost no impact. However, the boundary layer fluid adhering to the wall surface undergoes a subtle change in its flow state as it flows through these microribs: Each rib creates a tiny lift and disturbance to the underlying fluid. Behind the ribs, periodic, microscale vortex structures are generated. These microvortices promote mixing of the fluid within the boundary layer, rapidly smoothing out any possible circumferential unevenness in liquid film thickness. When this "homogenized" and "pre-activated" liquid film finally reaches nozzle 3 and expands outward, it is already in a more optimized unstable state, thus enabling it to break into uniform, fine droplets more consistently and rapidly.

[0069] Example 5 Reference Figure 4 and Figure 5 The centrifugal nozzle of this invention has a conical inner wall 4 in its swirling chamber 1. Spiral microribs 5 are machined onto this wall 4 using precision cutting or additive manufacturing techniques. The ribs are 50 micrometers high and 100 micrometers wide; their height is much smaller than the radius of the swirling chamber, only on the order of the liquid film boundary layer thickness.

[0070] Work process: Fuel enters the vortex chamber 1 at high speed from the tangential inlet 2, forming a rotating liquid film. The main body of the liquid film slides at high speed over the tips of the microribs 5 with almost no impact. However, the boundary layer fluid adhering to the wall surface undergoes a subtle change in its flow state as it flows through these microribs: Each rib creates a tiny lift and disturbance to the underlying fluid. Behind the ribs, periodic, microscale vortex structures are generated. These microvortices promote mixing of the fluid within the boundary layer, rapidly smoothing out any possible circumferential unevenness in liquid film thickness. When this "homogenized" and "pre-activated" liquid film finally reaches nozzle 3 and expands outward, it is already in a more optimized unstable state, thus enabling it to break into uniform, fine droplets more consistently and rapidly.

[0071] Thus, the objective of this invention has been achieved.

[0072] The above are merely preferred embodiments of the present invention and are not intended to limit the present invention. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present invention should be included within the protection scope of the present invention.

Claims

1. A centrifugal nozzle structure for enhanced atomization, comprising a swirling chamber and a nozzle, wherein the swirling chamber is provided with a tangential inlet, characterized in that: On the inner wall of the swirling chamber, at least one microrib structure is provided for disturbing the wall boundary layer fluid. The radial height of the microrib structure is on the same order of magnitude as the wall boundary layer thickness of the liquid film in the swirling chamber, so that the microrib structure mainly acts on the wall boundary layer, while having minimal impact on the main swirling flow.

2. The centrifugal nozzle structure for enhanced atomization according to claim 1, characterized in that: The microrib structure is a straight strip-shaped microrib extending along the axial direction of the swirl chamber, or a spiral-shaped microrib with a helix angle of less than 15°.

3. The centrifugal nozzle structure for enhanced atomization according to claim 1, characterized in that: The radial height of the microrib structure is 50 micrometers to 150 micrometers.

4. The centrifugal nozzle structure for enhanced atomization according to claim 1 or 2, characterized in that: The microrib structures are circumferentially distributed on the wall of the cyclone chamber; or, the microrib structures are non-uniformly distributed with denser distribution in specific areas on the wall of the cyclone chamber.

5. The centrifugal nozzle structure for enhanced atomization according to claim 1, characterized in that: The top surface morphology of the microrib structure is at least one of stepped, wavy, or serrated; and / or The radial height of the microrib structure gradually changes along the axial direction of the swirling chamber, decreasing or increasing from the inlet end to the nozzle end; and / or, The microrib structure is integrated on a separate, removable swirl chamber bushing, which is fitted inside the swirl chamber.

6. A method for enhancing the atomization effect of a centrifugal nozzle using a micro-rib structure, characterized in that, Includes the following steps: The fuel is drawn from the tangential inlet into the swirling chamber of the centrifugal nozzle, forming a high-speed rotating liquid film; By using microrib structures set on the inner wall of the swirl chamber, the liquid film boundary layer fluid closely attached to the wall is finely disturbed. The radial height of the microrib structure is on the same order of magnitude as the wall boundary layer thickness of the liquid film. The perturbation of the microrib structure promotes circumferential mixing of the fluid within the boundary layer, making the liquid film thickness distribution more uniform, and implanting controllable micro unstable waves within the boundary layer. The liquid film, disturbed by the micro-rib structure, is ejected from the nozzle, and under the action of the tiny unstable wave, more uniform and controllable atomization is achieved.

7. The method according to claim 6, characterized in that: The disturbance caused by the microrib structure causes the bottom layer of the liquid film to transition from a laminar or quasi-laminar state to a weakly turbulent state ahead of schedule.

8. The method according to claim 6, characterized in that: For fuels of different viscosities, the microrib structure adopts different macroscopic geometries; for high-viscosity fuels, low and wide weir-shaped microribs are used; for low-viscosity fuels, tall and slender wing-shaped microribs are used.

9. The method according to claim 6, characterized in that: The microrib structure is a straight strip-shaped microrib extending along the axial direction of the swirl chamber or a spiral microrib with a small helical angle; the straight strip-shaped microrib provides axial guidance for the fluid, or the spiral microrib provides axial velocity component for the fluid.

10. The method according to claim 6, characterized in that: By adjusting the circumferential distribution density, axial height gradient, or top surface morphology of the microrib structure, the boundary layer state of the liquid film during its development in the swirl chamber can be matched and optimized, thereby achieving customized control of the atomization effect.

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