A high-performance, small-volume intake adapter that adapts to complex intake routes

Abstract

The present invention belongs to the field of mechanical hydraulic and pneumatic technology, and specifically relates to a high-performance, small-volume intake adapter device that adapts to complex intake routes. It comprises a volute housing and a guide plate; the device utilizes a combination of a complex-shaped volute and a complex-shaped guide plate to achieve an intake adapter with eccentric intake, low total pressure loss, low intake distortion, high flight speed, matching of four branch plate channels, and small space occupation. The volute shape gradually changes from a rectangular cross-section at the inlet to two left and right channels, which can guide the gas flow more scientifically, match the downstream auxiliary power unit with a branch plate channel, reduce the separation zone in the upper area of the auxiliary power unit with a branch plate channel, and reduce flow losses.

Description

Technical Field

[0001] The present invention belongs to the technical field of mechanical hydraulics and pneumatics, and in particular relates to a high-performance, small-volume air intake adapter device adaptable to complex air intake routes. Background Art

[0002] Due to the particularity of the installation location, the design of the auxiliary power unit's air inlet is often limited by space, different flight or ground conditions, and the structure of the auxiliary power unit's air inlet. One such situation is that the aircraft provides relatively little space for the auxiliary power unit and its air inlet, requiring the air inlet route to be eccentric, meaning there's a significant distance between the upstream air inlet and the axis of the auxiliary power unit; the upstream air inlet has a rectangular cross-section, and the downstream auxiliary power unit has a built-in air inlet passage with four support plates; and the air inlet must operate both on the ground and in flight (at speeds exceeding 0.5 Ma). An air inlet adapter must be designed to meet the technical specifications of a low total pressure loss coefficient and a low total pressure distortion index in front of the auxiliary power unit's compressor inlet section under the designed air inlet flow conditions.

[0003] The most similar prior art to the present invention is the pressure-stabilizing chamber solution. This chamber is typically located within the intake airflow path, and its cross-sectional area is typically much larger than that of the upstream and downstream flow paths. Because the pressure-stabilizing chamber relies on static pressure balance within the chamber to improve intake uniformity for the downstream compressor, it is often referred to as a pressure-stabilizing chamber. Some practitioners also refer to it as a gas collecting chamber.

[0004] The specific working mechanism of the stabilization chamber is that after the gas in the chamber is decelerated to a very low momentum, the gas mixes and becomes uniform due to the effect of static pressure balance. The low-speed gas flow direction is more easily changed to be parallel to the downstream support plate, thus avoiding flow separation near the support plate and reducing gas flow losses. However, reducing the gas velocity to a sufficiently low level requires a large space, especially at high flight speeds (the maximum radius of the stabilization chamber can be 4.5 times the radius of the auxiliary power unit's air inlet). Therefore, the stabilization chamber solution is not suitable for this technical problem. Summary of the Invention

[0005] The purpose of the present invention is to provide a high-performance, small-volume air intake adapter device that can adapt to complex air intake routes. In a smaller space, it organizes a certain flow of airflow to make two turns through the eccentric air intake route and the air intake channel containing support plate (4) channels built into the auxiliary power unit, thereby meeting the technical indicators of low total pressure loss and low distortion index of the gas in the front section of the compressor under different flight and ground conditions.

[0006] The technical solution of the present invention: In order to achieve the above-mentioned purpose, a high-performance small-volume intake adapter device that adapts to complex intake routes is proposed, including a volute housing and a guide plate;

[0007] One end of the volute housing is an air inlet port, and the other end is an air outlet port, and the air inlet port is rectangular; the air flow is symmetrically divided into two sub-channels from the air inlet port to both sides, forming an eccentric air inlet route, and the extension directions of the two sub-channels are relatively far away from each other at first, and then smoothly transition to relatively convergence, so that the air intake realizes two turns through the eccentric air inlet route; the cross-sectional sides of the sub-channels gradually transition from straight sides to arc-shaped sides; the air outlet port of the volute housing is connected to the downstream auxiliary power unit with a support plate channel;

[0008] The guide plate is connected to the air outlet end of the volute casing, and includes an upper connecting guide plate, a middle guide plate, and a lower connecting guide plate axially symmetrically arranged on the two sub-channels; the upper connecting guide plates are symmetrically arranged on the upper inner sides of the air outlet ports of the two sub-channels, and are relatively gathered together; the lower connecting guide plates are symmetrically arranged on the lower inner sides of the air outlet ports of the two sub-channels, and are relatively gathered together; the middle guide plates are symmetrically arranged in the middle of the air outlet ports of the two channels, and are relatively gathered together.

[0009] In a possible embodiment, the volute casing is designed using computational fluid dynamics simulation software.

[0010] In a possible embodiment, the volute casing adopts a turbulence model using computational fluid dynamics simulation software, Shear Stress Transport.

[0011] In a possible embodiment, the volute casing is formed by splicing and combining a flat plate, a conical panel, and a cylindrical panel.

[0012] In a possible embodiment, the volute casing is made of metal.

[0013] In a possible embodiment, the upper connecting guide plate is in the shape of a sheet-like rectangle.

[0014] In a possible embodiment, the middle guide plate is in the shape of a curved sector, and the design is completed through aerodynamic research and optimization.

[0015] In a possible embodiment, the lower connecting guide plate is in the shape of a sheet-like rectangle.

[0016] Compared with the prior art, the present invention has the following beneficial effects:

[0017] The present invention comprehensively utilizes the combination of a complex-shaped volute and a complex-shaped guide plate to achieve eccentric air intake, low total pressure loss, low air intake distortion, higher flight speed, matching of 4-branch channel, and air intake transfer with small space occupation. The shape of the volute gradually changes from a rectangular cross-section at the inlet to two left and right channels, which can guide the gas flow more scientifically, match the downstream auxiliary power unit with a branch plate channel, reduce the separation zone in the upper area of the auxiliary power unit with a branch plate channel, and reduce flow losses. The guide plate 2 is set at a specific position near the horizontal branch plate of the auxiliary power unit to play the role of removing the separation zone of the flow channel below the horizontal branch plate. The shape of the guide plate 2 is specially designed, and its trailing edge is placed horizontally. By comparing the flow fields corresponding to different leading edge angles through aerodynamic research, the optimal shape is found, which can improve the flow field near the horizontal branch plate, remove the separation zone below the branch plate, reduce flow losses, and increase the air flow that can pass through. Part of the structure of the air intake adapter extends into the auxiliary power unit support plate channel, which is equivalent to changing the channel shape of the lower half of the auxiliary power unit support plate channel, which can reduce the airflow turning angle, reduce gas flow losses, and increase the gas flow rate that can pass through the lower half of the support plate channel. The volute is assembled using flat plates, conical panels, and cylindrical panels. It can be achieved only with plate materials, without relying on special mold processing, taking into account both process feasibility and economy, with low processing costs and short processing cycles. The air intake adapter occupies a small space, and its maximum radius is only 2.5 times the radius of the auxiliary power unit air inlet. The non-design operating performance of this air intake adapter is also relatively good, and all aerodynamic shapes are solutions with better comprehensive performance when considering different ground conditions and flight conditions. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a schematic diagram of the overall structure of a high-performance, small-volume intake adapter device that adapts to complex intake routes in a preferred embodiment of the present invention.

[0019] Figure 2 Schematic diagram of the downstream auxiliary power unit with support plate channel structure according to a preferred embodiment of the present invention

[0020] Figure 3 Schematic diagram of the assembly structure of the adapter device and the downstream auxiliary power unit with support plate channel according to the preferred embodiment of the present invention

[0021] Figure 4 Schematic diagram of the structure of the guide plate 2 according to the preferred embodiment of the present invention

[0022] Figure 5 Schematic diagram of aerodynamic simulation trace results of a preferred embodiment of the present invention

[0023] Figure 6 The aerodynamic simulation cloud diagram of the preferred embodiment of the present invention

[0024] in:

[0025] 1—volute casing, 2—middle guide plate, 3—upper connecting guide plate, 4—lower connecting guide plate, 5—channel casing with support plate, 6—horizontal support plate, 7—vertical support plate. DETAILED DESCRIPTION

[0026] In order to further understand the present invention, preferred embodiments of the present invention are described below in conjunction with examples. However, it should be understood that these descriptions are only for further illustrating the features and advantages of the present invention rather than limiting the patent claims of the present invention.

[0027] The present invention is applied to the connection between the auxiliary power unit and the aircraft nacelle air inlet. According to simulation analysis, the total pressure loss coefficient of the gas before the auxiliary power unit compressor is at most 3.7%, and the total pressure distortion index is at most 15%.

[0028] like Figure 1 As shown, a high-performance small-volume air intake adapter device matching a branch plate channel includes a volute housing 1, a middle guide plate 2, an upper connecting guide plate 3, and a lower connecting guide plate 4. The air intake adapter device is connected to the rectangular aircraft nacelle air intake channel upstream and to the auxiliary power unit branch plate channel (such as Figure 2 As shown, the channel with support plates is composed of a channel housing with support plates 5, a horizontal support plate 6 and a vertical support plate 7. The upper connecting guide plate 3 and the lower connecting guide plate 4 need to be inserted into the channel with support plates. The upper connecting guide plate 3 fits with the vertical support plate 7 above, and the lower connecting guide plate 4 fits with the lower curved surface of the channel housing with support plates 5. The airflow channel formed is as follows Figure 3 shown.

[0029] The shape of the volute housing 1 was designed through aerodynamic research and optimization to match the upstream rectangular cross-section and the downstream annular passage. The volute housing 1 is a complex three-dimensional form, composed of a combination of flat, conical, and cylindrical panels, taking into account process feasibility.

[0030] like Figure 4 As shown in FIG, the middle guide plate 2 is designed after aerodynamic research and optimization. The cross-sectional coordinate data are shown in Table 1. It is a complex three-dimensional shape, which can improve the flow field near the horizontal support plate 5, remove the separation area under the support plate, reduce flow losses, and increase the air flow rate that can pass through.

[0031] Table 1 Coordinate data of the cross section of the middle guide plate 2

[0032]

[0033]

[0034] The upper connecting guide plate 3 and the volute casing 1 form a bifurcated flow path, which more effectively guides gas flow and matches the downstream auxiliary power unit's support plate passage. Furthermore, the upper connecting guide plate 3, designed through aerodynamic research and optimization, reduces the separation zone above the auxiliary power unit's support plate passage, minimizing flow losses.

[0035] The lower connecting guide plate 4 fits the auxiliary power unit support plate channel shell 5, which is equivalent to changing the channel shape of the lower half of the auxiliary power unit support plate channel, reducing the airflow turning angle, reducing gas flow loss, and increasing the gas flow rate that can pass through the lower half of the support plate channel.

[0036] The aerodynamic simulation results under extreme conditions are as follows.

[0037] Under the conditions of an altitude of 0 km, an atmospheric temperature of 50°C, an atmospheric pressure of 101325 Pa, and an air flow rate of 11.12 kg / s, the upstream rectangular airflow channel, the air intake adapter, and the downstream airflow channel with four support plates were studied. An unstructured computational mesh was drawn, and the Shear Stress Transport turbulence model was selected. Through aerodynamic simulation, the aerodynamic performance parameters of the air intake adapter were obtained as follows:

[0038] After the airflow passes through the intake adapter and the downstream branch plate channel, the total pressure loss coefficient is 3.7% and the steady-state total pressure distortion index is 14.8%. Figure 5 There is no large flow separation area in the flow field. The airflow rates in the four channels separated by the support plate at the downstream are 2.92 kg / s, 2.78 kg / s at the lower left, 2.71 kg / s at the lower right, and 2.99 kg / s at the upper right. The total pressure distribution cloud and velocity distribution cloud at the outlet of the channel with support plate (compressor inlet) are shown in Fig. Figure 6 It can be seen that after the gas flows through the air intake adapter, the airflow is still relatively uniform.

[0039] In summary, the air intake adapter device can realize the air flow channel switching in a smaller space while ensuring good matching between the upstream and downstream air flow channels. Moreover, under the condition of large air intake flow, it can still ensure a low total pressure loss coefficient and steady-state total pressure distortion index, and high aerodynamic performance.

Claims

1. A high-performance, small-volume air intake adapter device adapted to complex air intake routes, characterized in that: It includes a volute casing and a guide plate; the upstream of the air intake adapter is connected to the air intake channel of the rectangular aircraft nacelle; One end of the volute casing is an air inlet port, and the other end is an air outlet port, and the air inlet port is rectangular; the air is symmetrically divided into two sub-channels from the inlet port to both sides, forming an eccentric air inlet route, and the extension directions of the two sub-channels are first relatively far away and then smoothly transition to relatively convergent, so that the air intake realizes two turns through the eccentric air intake route; the cross-sectional sides of the sub-channels gradually transition from straight sides to arc-shaped sides; the air outlet port of the volute casing is connected with the support plate channel of the downstream auxiliary power unit; the support plate channel of the downstream auxiliary power unit is composed of a channel casing with a support plate, a horizontal support plate and a vertical support plate; The guide plate is connected to the air outlet end of the volute shell, and includes an upper connecting guide plate, a middle guide plate, and a lower connecting guide plate that are axially symmetrically arranged on the two sub-channels; the upper connecting guide plates are symmetrically arranged on the inner sides of the upper parts of the air outlet ports of the two sub-channels, and are relatively gathered together; the lower connecting guide plates are symmetrically arranged on the inner sides of the lower parts of the air outlet ports of the two sub-channels, and are relatively gathered together; the middle guide plates are symmetrically arranged on the middle parts of the air outlet ports of the two channels, and are relatively gathered together; the upper connecting guide plate (3) and the lower connecting guide plate (4) need to extend into the channel with support plates, the upper connecting guide plate (3) is in contact with the upper vertical support plate (7), and the lower connecting guide plate (4) is in contact with the lower curved surface of the channel shell with support plates (5).

2. A high-performance, small-volume air intake adapter device adapted to complex air intake routes according to claim 1, characterized in that: The volute casing is designed using computational fluid dynamics simulation software.

3. A high-performance, small-volume air intake adapter device adapted to complex air intake routes according to claim 2, characterized in that: The volute casing adopts the computational fluid dynamics simulation software turbulence model selected as Shear Stress Transport.

4. The high-performance, small-volume air intake adapter device adapted to complex air intake routes according to claim 1 is characterized in that: The volute casing is formed by splicing and assembling a flat plate, a conical panel and a cylindrical panel.

5. The high-performance, small-volume air intake adapter device adapted to complex air intake routes according to claim 1 is characterized in that: The volute casing is made of metal.

6. The high-performance, small-volume air intake adapter device adapted to complex air intake routes according to claim 1 is characterized in that: The upper connecting guide plate is in the shape of a sheet-like rectangle.

7. The high-performance, small-volume air intake adapter device adapted to complex air intake routes according to claim 1 is characterized in that: The shape of the central guide plate is a curved fan, and the design is completed after aerodynamic research and optimization.

8. The high-performance, small-volume air intake adapter device adapted to complex air intake routes according to claim 1 is characterized in that: The lower connecting guide plate is in the shape of a sheet-like rectangle.

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