A water injection nozzle for fuel icing test

Abstract

The present application relates to a kind of water injection nozzle for fuel icing test, the nozzle is equipped with low-temperature main oil circuit, normal temperature water circuit, normal temperature auxiliary oil circuit;Part of normal temperature water circuit is located in low-temperature main oil circuit and is wrapped by normal temperature auxiliary oil circuit;Normal temperature water circuit is composed of normal temperature water circuit cyclone cavity connection port, normal temperature water circuit cyclone cavity guide hole, normal temperature water circuit cyclone cavity, normal temperature water circuit transition hole and normal temperature water circuit nozzle hole in turn connection;Normal temperature water circuit nozzle hole is located in low-temperature main oil circuit, and normal temperature auxiliary oil circuit is connected by normal temperature auxiliary oil circuit inlet end, normal temperature auxiliary oil circuit transition hole, normal temperature auxiliary oil circuit bend hole in turn connection.The present application utilizes nested nozzle configuration, and temperature isolation zone is established between low-temperature oil and normal temperature water by normal temperature oil provided by auxiliary oil circuit, temperature protection is realized to normal temperature water injected into low-temperature fuel environment, the local water temperature of nozzle outlet is maintained above freezing point, prevent normal temperature water injected from freezing early and block nozzle, can directly water distribution to low-temperature fuel.

Description

Technical Field

[0001] This invention belongs to the field of aircraft fuel system testing technology, and relates to a water injection nozzle for fuel icing tests. Background Technology

[0002] Aviation fuel may become contaminated with small amounts of water during refining, storage, transportation, and use, typically in the form of dissolved and free water. When an aircraft is cruising at high altitude (standard conditions: altitude 11 km, ambient temperature -56.5℃), the low temperature causes free water in the fuel to condense into ice. If effective de-icing measures are not taken, this ice can clog valves, pumps, filters, and screens, damaging the fuel system and seriously threatening flight safety. Therefore, fuel icing testing is crucial for airworthiness certification, and configuring water-containing fuel that meets specifications and design requirements is the first challenge to overcome.

[0003] Current fuel icing tests primarily employ offline water preparation, which involves first preparing saturated fuel at room temperature and then cooling it to the critical icing conditions that may be encountered during flight. Offline water preparation has the following main problems:

[0004] 1. The low water content of the prepared water-oil mixture corresponds to the saturated solubility at a certain temperature;

[0005] 2. The water content of the prepared water-oil mixture is difficult to adjust dynamically;

[0006] 3. When the prepared water-oil mixture arrives at the test specimen after a long transportation period, the composition homogeneity is poor;

[0007] 4. It is not possible to directly mix water with low-temperature fuel oil.

[0008] To further meet the experimental requirements of high-flow-rate online water injection in fuel systems under low-temperature conditions of -56.5℃, the development of a new type of fuel water injection nozzle has become an essential requirement. Summary of the Invention

[0009] The purpose of this invention is to provide a water injection nozzle for fuel icing tests, which can solve the above-mentioned problems.

[0010] According to the technical solution provided by the present invention: a water injection nozzle for fuel icing test, the nozzle is provided with a low-temperature main oil passage, a normal-temperature water passage, and a normal-temperature auxiliary oil passage; part of the normal-temperature water passage is located in the low-temperature main oil passage and is surrounded by the normal-temperature auxiliary oil passage; the normal-temperature water passage is composed of a normal-temperature water passage vortex cavity connection port, a normal-temperature water passage vortex cavity inlet hole, a normal-temperature water passage vortex cavity, a normal-temperature water passage transition hole, and a normal-temperature water passage nozzle hole connected in sequence; the normal-temperature water passage nozzle hole is located in the middle of the low-temperature main oil passage, and the normal-temperature auxiliary oil passage is composed of a normal-temperature auxiliary oil passage inlet end, a normal-temperature auxiliary oil passage transition hole, and a normal-temperature auxiliary oil passage bend hole connected in sequence.

[0011] As a further improvement of the present invention, the ambient temperature water vortex cavity is located above the nozzle and has an inverted frustum structure. The upper part of the ambient temperature water vortex cavity is connected from the inside to the outside to the inlet hole of the ambient temperature water vortex cavity and the connection port of the ambient temperature water vortex cavity. The lower part of the ambient temperature water vortex cavity is vertically connected to the upper end of the transition hole of the ambient temperature water path. The lower end of the transition hole of the ambient temperature water path is connected to the inner end of the nozzle hole of the ambient temperature water path. The outer end of the nozzle hole of the ambient temperature water path has an open structure.

[0012] As a further improvement of the present invention, the connection port of the ambient temperature water vortex cavity is horizontally placed above the nozzle, the connection port of the ambient temperature water vortex cavity is a threaded port, and the inlet hole and transition hole of the ambient temperature water vortex cavity are straight holes of equal diameter.

[0013] As a further improvement of the present invention, the inlet end of the ambient temperature auxiliary oil circuit is symmetrically arranged at the upper and lower ends of the nozzle. The upper and lower ends of the ambient temperature auxiliary oil circuit inlet end are connected through the ambient temperature auxiliary oil circuit transition hole. The left end of the ambient temperature auxiliary oil circuit bend hole wraps around the ambient temperature water circuit nozzle hole, and the right end of the ambient temperature auxiliary oil circuit bend hole is connected to the ambient temperature auxiliary oil circuit transition hole.

[0014] As a further improvement of the present invention, the water injection nozzle is formed by 3D additive manufacturing and an additive auxiliary rib is provided inside the water injection nozzle.

[0015] As a further improvement of the present invention, the additive auxiliary rib is composed of an additive auxiliary rib at the lower inlet of the ambient temperature auxiliary oil passage, an additive auxiliary rib at the upper inlet of the ambient temperature auxiliary oil passage, an additive auxiliary rib at the corner of the ambient temperature water passage, and additive auxiliary ribs for the direct connection sections of the ambient temperature water passage.

[0016] As a further improvement of the present invention, the thickness of the additive auxiliary rib at the lower inlet of the ambient temperature auxiliary oil circuit, the additive auxiliary rib at the upper inlet of the ambient temperature auxiliary oil circuit, the additive auxiliary rib at the corner of the ambient temperature water circuit, and the additive auxiliary rib at the direct connection section of the ambient temperature water circuit are all 2mm.

[0017] As a further improvement of the present invention, the inlet hole of the room temperature water vortex cavity is tangent to the upper cylindrical part of the room temperature water vortex cavity.

[0018] As a further improvement of the present invention, the axis of the connection port of the ambient temperature water vortex cavity is slightly lower than the axis of the inlet hole of the ambient temperature water vortex cavity, and the inner surfaces of the two are tangent.

[0019] The positive and progressive effects of this application are as follows:

[0020] 1. This invention utilizes a nested nozzle configuration, which establishes a temperature isolation zone between low-temperature oil and low-temperature water through the ambient temperature oil supplied by the auxiliary oil circuit. This provides temperature protection for the ambient temperature water injected into the low-temperature fuel environment, keeping the local water temperature at the nozzle outlet above the freezing point. This prevents the injected ambient temperature water from freezing prematurely and clogging the nozzle, and enables direct water distribution to low-temperature fuel.

[0021] 2. This invention introduces a vortex chamber in the room temperature water path, which imparts a circumferential rotational speed to the room temperature water during the water injection process, thereby facilitating thorough mixing of the room temperature water with the low-temperature oil in the main oil path. At the same time, when the emulsion pre-prepared by an ultrasonic stirrer with 90% aviation fuel and 10% distilled water is used instead of room temperature water during the test, the vortex effect can enhance the mixing of the emulsion during transportation, effectively maintain the uniformity of components, and reduce the probability of water-oil separation.

[0022] 3. By introducing a three-way pipe, this invention can reduce the impact of nozzle geometric asymmetry on the uniformity of the internal flow field of the low-temperature main oil circuit. At the same time, the three-way structure provides three room temperature oil injection modes, namely, the two straight inlet sections can be opened at the top and closed at the bottom, closed at the top and open at the bottom, or both at the top and bottom open at the same time. This provides multiple options for the pipeline connection of the external room temperature oil drive device at the test site. The mode of opening both at the top and bottom also enables the room temperature oil to have a circulation function.

[0023] 4. This invention utilizes an online water injection method for low-temperature fuel. By adjusting the flow ratio of the low-temperature main oil circuit, the normal-temperature auxiliary oil circuit, and the normal-temperature water circuit, the water content of the fuel can be dynamically adjusted, significantly increasing the upper limit of water content in the water-oil mixture compared to the offline water distribution method.

[0024] 5. This invention uses 3D additive manufacturing to integrally form the water injection nozzle. While reducing the machining difficulty caused by the complexity of the nozzle structure, it can significantly optimize the physical and chemical properties of the material and avoid the problem of poor water flow at room temperature due to misalignment, turning angles and gaps in the internal structure of the nozzle. Attached Figure Description

[0025] Figure 1 This is a 3D outline of the water injection nozzle.

[0026] Figure 2 This is a view of the nozzle from the perspective of the water inlet.

[0027] Figure 3 This is a symmetrical cross-sectional view of the water injection nozzle.

[0028] Figure 4 This is a sectional view of section AA.

[0029] Figure 5 This is a sectional view of section BB.

[0030] Figure 6 The image shows the velocity distribution along the X direction of the nested nozzles, represented by a YZ plane contour plot.

[0031] Figure 7 The distribution of temperature, velocity in the X direction, and water composition along the low-temperature main oil circuit is shown in the XZ plane cloud diagram and the Z-axis direction line diagram.

[0032] Figures 1-7The components include: 1. ambient temperature water circuit vortex chamber; 2. ambient temperature water circuit nozzle hole; 3. ambient temperature water circuit transition hole; 4. ambient temperature auxiliary oil circuit bend; 5. ambient temperature auxiliary oil circuit inlet end; 6. ambient temperature auxiliary oil circuit lower inlet additive auxiliary rib; 7. ambient temperature auxiliary oil circuit upper inlet additive auxiliary rib; 8. ambient temperature auxiliary oil circuit transition hole; 9. low temperature main oil circuit; 10. ambient temperature water circuit corner additive auxiliary rib; 11. ambient temperature water circuit straight connection section additive auxiliary rib; 12. ambient temperature water circuit vortex chamber connection port; 13. ambient temperature water circuit vortex chamber inlet hole. Detailed Implementation

[0033] It should be noted that, unless otherwise specified, the embodiments and features described in the present invention can be combined with each other. The present invention will now be described in detail with reference to the accompanying drawings and embodiments.

[0034] To enable those skilled in the art to better understand the present invention, the technical solutions of the present invention will be clearly and completely described below with reference to the accompanying drawings of the embodiments. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort should fall within the scope of protection of the present invention.

[0035] It should be noted that the terms "first," "second," etc., in the specification, claims, and accompanying drawings of this invention are used to distinguish similar objects and are not necessarily used to describe a specific order or sequence. It should be understood that such data can be interchanged where appropriate for the embodiments of the invention described herein. Furthermore, terms such as "comprising" and "having" mean that in addition to those already listed in "comprising" and "having," other unlisted contents may also be included; for example, a process, method, system, product, or device may include a series of steps or units, not necessarily limited to those steps or units explicitly listed, but may include other steps or units not explicitly listed or inherent to these processes, methods, products, or devices.

[0036] Due to the angle of the drawing, some parts may not be drawn, but their positions and connections can be understood from the text descriptions.

[0037] like Figure 1 As shown, the present invention is a water injection nozzle for fuel icing tests. The nozzle is provided with a low-temperature main oil passage 9, a normal temperature water passage, and a normal temperature auxiliary oil passage; part of the normal temperature water passage is located in the low-temperature main oil passage 9 and is surrounded by the normal temperature auxiliary oil passage.

[0038] The ambient temperature water circuit is used to inject ambient temperature water into the low temperature main oil circuit 9; it consists of the ambient temperature water circuit vortex cavity connection port 12, the ambient temperature water circuit vortex cavity inlet hole 13, the ambient temperature water circuit vortex cavity 1, the ambient temperature water circuit transition hole 3, and the ambient temperature water circuit nozzle hole 2 connected in sequence.

[0039] like Figure 3 As shown, the ambient temperature water vortex chamber 1 is located above the nozzle and has an inverted frustum structure, as... Figure 4 As shown, the upper part of the ambient temperature water vortex cavity 1 is connected from the inside to the outside to the ambient temperature water vortex cavity inlet hole 13 and the ambient temperature water vortex cavity connection port 12. The lower part of the ambient temperature water vortex cavity 1 is vertically connected to the upper end of the ambient temperature water transition hole 3. The lower end of the ambient temperature water transition hole 3 is connected to the inner end of the ambient temperature water nozzle hole 2. The outer end of the ambient temperature water nozzle hole 2 has an open structure.

[0040] The ambient temperature water vortex chamber connection port 12 is horizontally positioned above the nozzle. The outer end of the ambient temperature water vortex chamber connection port 12 is used to connect to ambient temperature water, and the inner end of the ambient temperature water vortex chamber connection port 12 is connected to the ambient temperature water vortex chamber inlet hole 13. The ambient temperature water vortex chamber connection port 12 is a threaded port. The ambient temperature water vortex chamber inlet hole 13 and the ambient temperature water transition hole 3 are straight holes of equal diameter.

[0041] The normal temperature water circuit nozzle hole 2 is located in the middle of the low temperature main oil circuit 9.

[0042] The ambient temperature auxiliary oil circuit is used to inject ambient temperature oil, which provides temperature protection, into the low temperature main oil circuit 9. It consists of an ambient temperature auxiliary oil circuit inlet 5, an ambient temperature auxiliary oil circuit transition hole 8, and an ambient temperature auxiliary oil circuit bend 4 connected in sequence. The ambient temperature auxiliary oil circuit inlet 5 is symmetrically arranged at the upper and lower ends of the nozzle. The upper and lower ends of the ambient temperature auxiliary oil circuit inlet 5 are connected through the ambient temperature auxiliary oil circuit transition hole 8. The left end of the ambient temperature auxiliary oil circuit bend 4 covers the ambient temperature water circuit nozzle hole 2, and the right end of the ambient temperature auxiliary oil circuit bend 4 is connected to the ambient temperature auxiliary oil circuit transition hole 8.

[0043] The water injection nozzle is manufactured using 3D additive manufacturing. The nozzle is equipped with additive auxiliary ribs, which play a connecting role in the 3D additive manufacturing process.

[0044] The additive auxiliary rib consists of additive auxiliary rib 6 at the lower inlet of the ambient temperature auxiliary oil circuit, additive auxiliary rib 7 at the upper inlet of the ambient temperature auxiliary oil circuit, additive auxiliary rib 10 at the corner of the ambient temperature water circuit, and additive auxiliary rib 11 at the direct connection section of the ambient temperature water circuit, all with a thickness of 2mm.

[0045] Before being put into testing, the water injection nozzle needs to undergo enhanced heat treatment and be precision machined to obtain the precise outlet diameter of the room temperature water channel nozzle hole 2.

[0046] The ambient temperature auxiliary oil passage bend 4 encloses the ambient temperature water passage nozzle hole 2 inside, forming a nested configuration, and the outlet section of the ambient temperature auxiliary oil passage bend 4 slightly extends beyond the outlet section of the ambient temperature water passage nozzle hole 2. The nested configuration allows the ambient temperature oil to provide temperature protection for the ambient temperature water, preventing the ambient temperature water from freezing prematurely at the outlet and clogging the nozzle.

[0047] The inlet hole 13 of the ambient temperature water vortex cavity is tangential to the upper cylindrical part of the ambient temperature water vortex cavity 1, such as... Figure 4 As shown, this is to ensure that the inlet velocity of the room temperature water is fully converted into the circumferential velocity at the nozzle outlet position.

[0048] The axis of the connection port 12 of the ambient temperature water vortex chamber is slightly lower than the axis of the inlet hole 13 of the ambient temperature water vortex chamber, and their inner surfaces are tangent. Figure 2 As shown, this is to reduce the overall height of the water injection nozzle.

[0049] The working process of this invention is as follows:

[0050] In response to the icing test requirements of a certain type of aircraft fuel system, the water injection nozzle configuration described in this invention was used to perform three-dimensional numerical simulation calculations of the flow field under specific icing conditions, and the relevant performance parameters were summarized.

[0051] Figure 6 This diagram illustrates the velocity distribution along the X-direction of a nested nozzle, represented by a YZ plane contour plot, under conditions of -55℃ fuel temperature, 20℃ water / fuel injection temperature, and 17830ppmV fuel water content. Between X=15mm and 35mm, influenced by the geometry of the nested nozzle, the cross-section of the ambient temperature auxiliary fuel path first shrinks from a circle to a crescent shape, then extends to a ring shape. At the selected cross-section, the velocity of the ambient temperature fuel in the X-direction dynamically changes, ultimately achieving a well-uniform velocity distribution at the nozzle outlet. For the ambient temperature water path inside the nested nozzle, velocity non-uniformity caused by the swirling effect can be observed at X=30mm; the velocity direction in the dark area on the left is perpendicular to the paper and outwards, while the velocity direction in the light area on the right is perpendicular to the paper and inwards. When the ambient temperature water reaches near the nozzle outlet at X=55mm, an ideal velocity gradient has been formed.

[0052] In this embodiment, the water injection nozzle is installed in the opposite direction to form a flow field that injects fuel in the opposite direction to the main pipeline. To facilitate the examination of the flow field recovery at a distance from the nozzle, the computational domain is expanded to X = -280mm - 160mm in the three-dimensional numerical simulation of the flow field. Figure 7The diagrams sequentially show the temperature, velocity in the X direction, and water component distribution along the cryogenic main fuel path, represented by XZ plane cloud maps and Z-axis direction line diagrams. The results indicate that within a limited pipeline length from the nozzle outlet, the flow field temperature and velocity can regain uniformity. Due to the differences in the physical properties of water and oil media, the water component distribution exhibits a local peak in the middle region of the pipeline, and this peak gradually decreases with increasing mixing distance (X=-280mm, approximately 15%). If a pre-prepared emulsion is used instead of room-temperature water injected into the cryogenic fuel, it is expected to further reduce the water component peak. In particular, compared to forward-mounted water injection nozzles, the impact of reverse injection is beneficial for improving water-oil mixing, and the injected room-temperature water / emulsion re-adheres to the surface of the nested nozzle, providing good temperature protection for the entire nozzle in cryogenic environments.

[0053] The above description is only a preferred embodiment of the present invention. It should be noted that those skilled in the art can make several improvements and modifications without departing from the concept of the present invention, and these improvements and modifications should also be considered within the scope of protection of the present invention.

Claims

1. A water injection nozzle for fuel icing tests, characterized in that, The nozzle is equipped with a low-temperature main oil passage (9), a normal-temperature water passage, and a normal-temperature auxiliary oil passage. Part of the normal-temperature water passage is located in the low-temperature main oil passage (9) and is surrounded by the normal-temperature auxiliary oil passage. The normal-temperature water passage consists of the normal-temperature water passage vortex chamber connection port (12), the normal-temperature water passage vortex chamber inlet hole (13), the normal-temperature water passage vortex chamber (1), the normal-temperature water passage transition hole (3), and the normal-temperature water passage nozzle hole (2) connected in sequence. The normal-temperature water passage nozzle hole (2) is located in the middle of the low-temperature main oil passage (9). The normal-temperature auxiliary oil passage consists of the normal-temperature auxiliary oil passage inlet end (5), the normal-temperature auxiliary oil passage transition hole (8), and the normal-temperature auxiliary oil passage bend hole (4) connected in sequence. The normal-temperature auxiliary oil passage inlet end (5) is symmetrically arranged at the upper and lower ends of the nozzle. The inlet end (5) of the ambient temperature auxiliary oil circuit is connected through the ambient temperature auxiliary oil circuit transition hole (8). The left end of the ambient temperature auxiliary oil circuit bend (4) wraps around the ambient temperature water circuit nozzle hole (2), and the right end of the ambient temperature auxiliary oil circuit bend (4) is connected to the ambient temperature auxiliary oil circuit transition hole (8). The ambient temperature water circuit vortex cavity (1) is located above the nozzle and has an inverted frustum structure. The upper part of the ambient temperature water circuit vortex cavity (1) is connected from the inside to the outside to the ambient temperature water circuit vortex cavity inlet hole (13) and the ambient temperature water circuit vortex cavity connection port (12). The lower part of the ambient temperature water circuit vortex cavity (1) is vertically connected to the upper end of the ambient temperature water circuit transition hole (3). The lower end of the ambient temperature water circuit transition hole (3) is connected to the inner end of the ambient temperature water circuit nozzle hole (2). The outer end of the ambient temperature water circuit nozzle hole (2) has an open structure.

2. The water injection nozzle for fuel icing tests as described in claim 1, characterized in that, The normal temperature water vortex cavity connection port (12) is horizontally placed above the nozzle. The normal temperature water vortex cavity connection port (12) is a threaded port. The normal temperature water vortex cavity inlet hole (13) and the normal temperature water vortex cavity transition hole (3) are straight holes of equal diameter.

3. The water injection nozzle for fuel icing tests as described in claim 1, characterized in that, The water injection nozzle is manufactured using 3D additive manufacturing, and an additive auxiliary rib is provided inside the nozzle.

4. The water injection nozzle for fuel icing tests as described in claim 3, characterized in that, The additive auxiliary rib consists of an additive auxiliary rib at the lower inlet of the ambient temperature auxiliary oil circuit (6), an additive auxiliary rib at the upper inlet of the ambient temperature auxiliary oil circuit (7), an additive auxiliary rib at the corner of the ambient temperature water circuit (10), and an additive auxiliary rib at the direct connection section of the ambient temperature water circuit (11).

5. The water injection nozzle for fuel icing tests as described in claim 4, characterized in that, The thickness of the additive auxiliary rib plate (6) at the lower inlet of the ambient temperature auxiliary oil circuit, the additive auxiliary rib plate (7) at the upper inlet of the ambient temperature auxiliary oil circuit, the additive auxiliary rib plate (10) at the corner of the ambient temperature water circuit, and the additive auxiliary rib plate (11) at the direct connection section of the ambient temperature water circuit are all 2mm.

6. The water injection nozzle for fuel icing test as described in claim 1, characterized in that, The inlet hole (13) of the ambient temperature water vortex cavity is tangent to the upper cylindrical part of the ambient temperature water vortex cavity (1).

7. The water injection nozzle for fuel icing tests as described in claim 1, characterized in that, The axis of the connection port (12) of the ambient temperature water vortex cavity is slightly lower than the axis of the inlet hole (13) of the ambient temperature water vortex cavity, and the inner surfaces of the two are tangent.

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