Two-stage atomizing nozzle and water ramjet injector

Abstract

The invention discloses a water ramjet injector, which is characterized in that a core component is a centrifugal two-stage atomizing nozzle, and a two-stage duct design is adopted in the centrifugal two-stage atomizing nozzle: the first stage is a communicating cavity, high-pressure water flow enters the first atomizing cavity and then is accelerated by the communicating cavity, a strong shearing effect is generated due to sudden change of the aperture, and high-Reynolds-number turbulent flow, namely first-stage atomization, is formed; and then the fluid enters the second atomization cavity and interacts with the gas medium at an outlet, and the liquid film is further crushed into micron-sized fog drops, namely second-stage atomization. The nozzles are restrained to the inner wall of the combustion chamber through threads in a circumferential axial symmetry mode, and the jet flow axes and angles of the multiple nozzles are reasonably arranged, so that atomized water media achieve self-impact collision in the center area of the combustion chamber. In the collision process, through momentum accumulation and turbulence disturbance, liquid drops are promoted to be subjected to secondary crushing, the atomization uniformity and the mixing efficiency are remarkably improved, and the method is suitable for large-scale industrial use and popularization.

Description

Technical Field

[0001] This invention belongs to the technical field of underwater propulsion devices, specifically relating to a two-stage atomizing nozzle and a water jet engine injector. Background Technology

[0002] A water ramjet engine is an underwater propulsion device. Its basic working principle is to rely on high-speed ramjet to draw in seawater as an oxidant, which reacts with the metal-based fuel it carries to produce high-temperature, high-pressure gas that is injected through a nozzle to generate thrust.

[0003] One of the technological bottlenecks in existing water ramjet engines lies in achieving efficient atomization of liquid water. The physical properties of water make its atomization far more difficult than that of conventional hydrocarbon fuels. Insufficient atomization can lead to slow evaporation, uneven mixing with metallic fuels, and low reaction efficiency. Therefore, the quality of atomization directly determines the degree of mixing between fuel and water, the combustion rate, and the engine's thrust performance. As the core component for achieving liquid water atomization, the nozzle's performance is a key factor affecting the overall efficiency of the water ramjet engine.

[0004] Existing technologies lack in-depth optimization of nozzle structure specifically for the difficulty of atomizing liquid water, and lack a systematic solution that deeply couples efficient internal atomization mechanisms with secondary additions in macroscopic layout, resulting in low overall efficiency of water ramjet engines. Summary of the Invention

[0005] The purpose of this invention is to provide a two-stage atomizing nozzle and a water-jet engine injector to solve the problem of low overall efficiency of water-jet engines in the prior art.

[0006] To solve the above-mentioned technical problems, the present invention adopts the following technical solution:

[0007] A two-stage atomizing nozzle, wherein the two-stage atomizing nozzle is open at both ends, serving as an inlet end and an outlet end respectively; wherein the inlet end of the two-stage atomizing nozzle includes a plurality of inlet ports evenly opened along the circumference, and each inlet port is connected to the output end of an external liquid injection device. The two-stage atomizing nozzle has a first atomizing chamber, a connecting chamber, and a second atomizing chamber coaxially and sequentially formed along its length; the inner diameter of the first atomizing chamber is larger than that of the second atomizing chamber, and the inner diameter of the second atomizing chamber is larger than that of the connecting chamber. The first atomizing chamber is connected to multiple liquid inlets; the second atomizing chamber is connected to the liquid outlet of the two-stage atomizing nozzle.

[0008] The present invention also has the following features: Furthermore, the inner diameter of the first atomizing chamber gradually decreases at the end near the connecting chamber; The inner diameter of the second atomizing chamber gradually decreases at the end near the connecting chamber; The inner diameter of the second atomizing chamber gradually increases at the end furthest from the connecting chamber.

[0009] Furthermore, the two-stage atomizing nozzle has three liquid inlets evenly distributed circumferentially at one end, and the liquid inlet direction is tangent to the injector housing.

[0010] A water-jet engine injector based on the above-mentioned two-stage atomizing nozzle includes a combustion chamber cavity disposed inside the water-jet engine, wherein a first injector and a second injector are coaxially disposed on both sides of the combustion chamber cavity. The first injector and the second injector have the same structure and specifications. The first injector includes an injector housing. The injector housing is coaxially and fixedly connected to the combustion chamber cavity, and the inside of the injector housing is connected to the combustion chamber cavity. The injector housing is provided with a plurality of two-stage atomizing nozzles evenly arranged along the circumference, and the liquid outlet end of the two-stage atomizing nozzles is located inside the injector housing.

[0011] Furthermore, an annular liquid collection chamber is provided inside the injector housing; the liquid inlet of the liquid collection chamber is connected to an external liquid injection device, and the liquid inlet of the two-stage atomizing nozzle is located inside the liquid collection chamber.

[0012] Furthermore, the injector housing is provided with 4-6 two-stage atomizing nozzles evenly arranged circumferentially. Furthermore, the connection between the injector housing and the combustion chamber cavity is a flange connection.

[0013] Furthermore, the injector housing sidewall is provided with multiple positioning bosses along the circumference, and the combustion chamber cavity sidewall is provided with positioning grooves corresponding to the multiple positioning bosses. Furthermore, the injector housing is provided with multiple nozzle positioning grooves, and the two-stage atomizing nozzles are respectively positioned inside the nozzle positioning grooves.

[0014] Furthermore, an O-ring is provided inside the nozzle positioning groove.

[0015] Compared with the prior art, the present invention has the following technical effects: The core component of the water-jet engine injector of this invention is a centrifugal two-stage atomizing nozzle, which employs a two-stage channel design: the first stage is a connecting chamber, where high-pressure water enters and is accelerated. The abrupt change in orifice size generates strong shearing, creating high Reynolds number turbulence, i.e., first-stage atomization. Subsequently, the fluid enters the second atomizing chamber, where it interacts with the gaseous medium at the outlet, further breaking the liquid film into micron-sized droplets, i.e., second-stage atomization. The nozzles are circumferentially axisymmetrically constrained to the combustion chamber wall via threads. The jet axes and angles of multiple nozzles are rationally set, enabling the atomized water medium to achieve self-collision in the central region of the combustion chamber. This collision process, through momentum accumulation and turbulent disturbance, promotes secondary droplet breakage, significantly improving atomization uniformity and mixing efficiency, making it suitable for large-scale industrial use and promotion. Attached Figure Description

[0016] Figure 1 This is a cross-sectional view of the water jet engine injector of the present invention; Figure 2 This is a cross-sectional view of the first injector in this invention; Figure 3 This is a cross-sectional view of the combustion chamber cavity in this invention; Figure 4 This is a cross-sectional view of the two-stage atomizing nozzle in this invention.

[0017] The meanings of the labels in the diagram are as follows: 1. Combustion chamber; 2. First injector; 3. Second injector; 4. Injector housing; 5. Two-stage atomizing nozzle; 6. Liquid collection chamber; 7. Positioning boss; 8. Positioning groove; 9. Nozzle positioning groove; 10. O-ring seal.

[0018] 501, Liquid inlet; 502, First atomizing chamber; 503, Connecting chamber; 504, Second atomizing chamber. Detailed Implementation

[0019] It should be noted that, unless otherwise specified, all components in this invention are known in the prior art. For example, the combustion chamber cavity uses a commonly known combustion chamber cavity.

[0020] The following are specific embodiments of the present invention. It should be noted that the present invention is not limited to the following specific embodiments. All equivalent modifications made based on the technical solutions of this application fall within the protection scope of the present invention.

[0021] like Figure 4 As shown, a two-stage atomizing nozzle 5 is provided with open ends, serving as an inlet and an outlet respectively; wherein, the inlet end of the two-stage atomizing nozzle 5 includes a plurality of inlet ports 501 evenly opened along the circumference, and each inlet port 501 is connected to the output end of an external liquid injection device. The two-stage atomizing nozzle 5 has a first atomizing chamber 502, a connecting chamber 503, and a second atomizing chamber 504 coaxially and sequentially formed along its length. The inner diameter of the first atomizing chamber 502 is larger than that of the second atomizing chamber 504, and the inner diameter of the second atomizing chamber 504 is larger than that of the connecting chamber 503. The first atomizing chamber 502 is connected to multiple liquid inlets 501; the second atomizing chamber 504 is connected to the liquid outlet of the two-stage atomizing nozzles 5.

[0022] As a preferred embodiment, the inner diameter of the first atomizing chamber 502 gradually decreases at the end near the connecting chamber 503; The inner diameter of the second atomizing chamber 504 gradually decreases at the end near the connecting chamber 503; The inner diameter of the second atomizing chamber 504 gradually increases at the end furthest from the connecting chamber 503.

[0023] More preferably, one end of the two-stage atomizing nozzle 5 is provided with three liquid inlets 501 evenly distributed circumferentially, and the liquid inlet direction of the liquid inlet 501 is tangent to the injector housing 4.

[0024] The workflow of the two-stage atomizing nozzle 5 in this embodiment is as follows: An external injection device injects high-pressure liquid water into the interior of the two-stage atomizing nozzle 5 through the inlet 501. After the high-pressure water flows into the first atomizing chamber 502, its flow direction changes, and it is accelerated through the connecting chamber. Due to the sudden change in flow direction and aperture, a strong shearing effect is generated, forming a high Reynolds number turbulence.

[0025] It should be noted that the Reynolds number is a dimensionless number used to measure the ratio of inertial forces (the tendency of a fluid to remain in motion) to viscous forces (the internal frictional forces that impede the deformation and motion of the fluid) in a fluid.

[0026] When liquid water enters the two-stage atomizing nozzle 5, on the one hand, due to the small orifice of the connecting cavity 503, the liquid flows at an extremely high velocity, resulting in inertial force dominating. On the other hand, the relatively low viscosity of water further weakens the stabilizing effect of viscous force.

[0027] When the Reynolds number exceeds a critical value, the stable laminar flow state can no longer be maintained. Tiny disturbances caused by inertial forces are rapidly amplified, and the flow becomes chaotic, disordered, and filled with eddies of various scales—this is turbulence. These turbulent eddies generate intense pressure and velocity fluctuations, continuously impacting, torturing, and stretching the already partially sheared water, providing enormous and efficient energy for further atomization. The stronger the turbulence, the better the atomization effect.

[0028] When the atomized water is sprayed out from the outlet at the other end of the two-stage atomizing nozzle 5, the atomization effect is better than that of the atomizing nozzles in the prior art.

[0029] The advantages of the two-stage atomizing nozzle 5 in this embodiment will be further explained below: 1. The two-stage atomizing nozzle 5 in this embodiment is different from the pressure atomizing nozzle in the prior art: Existing pressure atomizing nozzles primarily rely on the pressure of the liquid itself to accelerate and break it up. Their working principle involves causing the liquid to rotate at high speed within a vortex chamber, forming a liquid mist upon exiting the nozzle. The atomization effect of these nozzles is significantly limited by the physical properties of water; relying solely on centrifugal effect often fails to produce sufficiently fine and uniform droplets. Furthermore, their atomization quality is highly dependent on the water supply pressure, and performance degrades significantly under low operating conditions. By employing the two-stage atomizing nozzle 5 of this embodiment, atomization is no longer solely dependent on water pressure, predictably improving the atomization effect.

[0030] 2. The two-stage atomizing nozzle 5 in this embodiment is different from the pneumatic atomizing nozzle in the prior art: Pneumatic atomization technology introduces a high-speed airflow, utilizing the strong shearing action between the gas and liquid phases to break up the liquid. The advantage of this technology is that it can achieve good atomization fineness at relatively low liquid pressure. However, its significant disadvantage is that it requires an auxiliary air source, increasing the uncertainty and complexity of the system. Furthermore, the stability control of the gas-liquid two-phase flow is a major challenge, making it unsuitable for simple application in water-ramjet engines. In this embodiment, the two-stage atomizing nozzle 5 eliminates the need for an additional air source, utilizing the energy generated by the impact to promote liquid spreading and breaking up, thereby improving the atomization effect.

[0031] like Figure 1-4 As shown, a water-jet engine injector based on a two-stage atomizing nozzle includes a combustion chamber 1 disposed inside the water-jet engine, with a first injector 2 and a second injector 3 coaxially and sealed on both sides of the combustion chamber 1. The first injector 2 and the second injector 3 have the same structure and specifications. The first injector 2 includes an injector housing 4. The injector housing 4 is coaxially and fixedly connected to the combustion chamber cavity 1, and the inside of the injector housing 4 is connected to the combustion chamber cavity 1. Multiple two-stage atomizing nozzles 5 are evenly arranged along the circumference of the injector housing 4. Multiple liquid inlets 501 are opened at one end of the two-stage atomizing nozzles 5. Each liquid inlet 501 is connected to an external liquid injection device. The liquid outlet at the other end of the two-stage atomizing nozzles 5 is located inside the injector housing 4. The two-stage atomizing nozzle 5 has a first atomizing chamber 502, a connecting chamber 503, and a second atomizing chamber 504 coaxially and sequentially formed along its length. The inner diameter of the first atomizing chamber 502 is larger than that of the second atomizing chamber 504, and the inner diameter of the second atomizing chamber 504 is larger than that of the connecting chamber 503. The second atomizing chamber 504 is connected to the liquid outlet of the two-stage atomizing nozzle 5.

[0032] The following provides a further explanation of the working process of the water jet engine injector in this embodiment: An external injection device injects high-pressure liquid water into the two-stage atomizing nozzle 5 through the inlet 501. The high-pressure liquid water is atomized in the two-stage atomizing nozzle 5, and the atomized water enters the injector housing 4 from the outlet at the other end of the two-stage atomizing nozzle 5. The atomized water medium further enters the combustion chamber 1, where it undergoes self-collision in the central region of the combustion chamber 1. This collision process, through momentum accumulation and turbulent disturbance, promotes secondary breakup of the droplets, significantly improving atomization uniformity and mixing efficiency.

[0033] Specifically, high-pressure water enters from the first injector 2 and is atomized by the two-stage atomizing nozzles 5 of the first injector 2. Similarly, another stream of water enters from the second injector 3 and is atomized by the two-stage atomizing nozzles 5 of the first injector 2.

[0034] The two streams of atomized water collide, break up again, and mix thoroughly within the combustion chamber 1. The mixed water mist then comes into full contact with the metallic fuel particles entering the combustion chamber 1, achieving efficient combustion and improving combustion efficiency.

[0035] In one specific implementation, a liquid collection chamber 6 is provided inside the injector housing 4; the liquid inlet of the liquid collection chamber 6 is connected to an external liquid injection device, and the liquid inlet of the two-stage atomizing nozzle 5 is located inside the liquid collection chamber 6.

[0036] As one specific implementation, 4 to 6 two-stage atomizing nozzles 5 are evenly arranged circumferentially on the injector housing 4; The two-stage atomizing nozzle 5 has three liquid inlets 501 evenly distributed around its circumference at one end, and the liquid inlet direction of the liquid inlet 501 is tangent to the injector housing 4.

[0037] As a preferred option, the injector housing 4 and the combustion chamber cavity 1 are connected by a flange connection to improve the connection strength between the two.

[0038] As a preferred embodiment, the injector housing 4 has multiple positioning protrusions 7 circumferentially formed on its side wall, and the combustion chamber cavity 1 has positioning grooves 8 corresponding to the multiple positioning protrusions 7 on its side wall, so as to facilitate the alignment of the injector housing 4 and the combustion chamber cavity 1 and achieve a more efficient connection.

[0039] As a preferred option, the injector housing 4 is provided with multiple nozzle positioning grooves 9, and the two-stage atomizing nozzles 5 are correspondingly arranged inside the nozzle positioning grooves 9 to improve the connection stability between the two.

[0040] In a further preferred embodiment, an O-ring 10 is provided inside the nozzle positioning groove 9 to improve the sealing performance of the two-stage atomizing nozzle 5 inside the nozzle positioning groove 9.

Claims

1. A two-stage atomizing nozzle, characterized in that, The two-stage atomizing nozzle (5) is open at both ends, serving as the liquid inlet and liquid outlet respectively; wherein, the liquid inlet of the two-stage atomizing nozzle (5) includes a plurality of liquid inlets (501) evenly opened along the circumference, and each liquid inlet (501) is connected to the output end of an external liquid injection device. The two-stage atomizing nozzle (5) has a first atomizing chamber (502), a connecting chamber (503), and a second atomizing chamber (504) coaxially and sequentially opened along the length direction; the inner diameter of the first atomizing chamber (502) is larger than that of the second atomizing chamber (504), and the inner diameter of the second atomizing chamber (504) is larger than that of the connecting chamber (503). The first atomizing chamber (502) is connected to multiple liquid inlets (501); the second atomizing chamber (504) is connected to the liquid outlet of the two-stage atomizing nozzle (5).

2. The two-stage atomizing nozzle as described in claim 1, characterized in that, The inner diameter of the first atomizing chamber (502) gradually decreases at the end near the connecting chamber (503); The inner diameter of the second atomizing chamber (504) gradually decreases at the end near the connecting chamber (503); The inner diameter of the end of the second atomizing chamber (504) away from the connecting chamber (503) gradually increases.

3. The two-stage atomizing nozzle as described in claim 2, characterized in that, The two-stage atomizing nozzle (5) has three liquid inlets (501) evenly distributed around one end in the circumference. The liquid inlet (501) is tangent to the injector housing (4) in the direction of liquid inlet.

4. A water-jet engine injector based on the two-stage atomizing nozzle of claim 3, comprising a combustion chamber cavity (1) disposed inside the water-jet engine, characterized in that, The combustion chamber cavity (1) is provided with a first injector (2) and a second injector (3) on both sides coaxially. The first injector (2) and the second injector (3) have the same structure and specifications. The first injector (2) includes an injector housing (4). The injector housing (4) is coaxially fixedly connected to the combustion chamber cavity (1), and the inside of the injector housing (4) is connected to the combustion chamber cavity (1). The injector housing (4) is uniformly provided with multiple two-stage atomizing nozzles (5) along the circumference, and the liquid outlet end of the two-stage atomizing nozzles (5) is located inside the injector housing (4).

5. The water jet engine injector as described in claim 4, characterized in that, The injector housing (4) has an annular liquid collection chamber (6) inside; the liquid inlet of the liquid collection chamber (6) is connected to an external liquid injection device, and the liquid inlet (501) of the two-stage atomizing nozzle (5) is located inside the liquid collection chamber (6).

6. The water jet engine injector as described in claim 5, characterized in that, The injector housing (4) is provided with 4-6 two-stage atomizing nozzles (5) evenly arranged along the circumference.

7. The water-jet engine injector as described in any one of claims 6, characterized in that, The injector housing (4) and the combustion chamber cavity (1) are connected by a flange connection.

8. The water jet engine injector as described in claim 7, characterized in that, The injector housing (4) has multiple positioning bosses (7) arranged circumferentially on its side wall, and the combustion chamber cavity (1) has positioning grooves (8) that correspond one-to-one with the multiple positioning bosses (7) on its side wall.

9. The water jet engine injector as described in claim 7, characterized in that, The injector housing (4) is provided with multiple nozzle positioning grooves (9), and the two-stage atomizing nozzles (5) are respectively arranged inside the nozzle positioning grooves (9).

10. The water jet engine injector as described in claim 8, characterized in that, The nozzle positioning groove (9) is provided with an O-ring (10).

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