A hybrid device with ejection, sound attenuation and low flow resistance

Abstract

The application discloses a kind of mixed devices with injection noise reduction low flow resistance.It includes mixing air pipe (1), hot air ring cavity (2) is embedded on the pipe body near upstream inlet, hot air ring cavity (2) is communicated with injection ball (4) on the central axis of mixing air pipe (1) by injection rod (3);Hot air ring cavity (2) is embedded in the cavity wall of mixing air pipe (1), and the shunt hole (5) is distributed in the circumferential direction, while the shunt hole (5) orifice is towards the central axis of mixing air pipe (1) along the side of back to mixing air pipe (1) inlet;The injection ball (4) is distributed with injection hole (6), and the injection hole (6) orifice is back to mixing air pipe (1) inlet, while the orifice is towards the central axis of mixing air pipe (1).The application has injection function, and has the characteristics of low noise, cold and hot air mixing fully and low flow resistance.

Description

Technical Field

[0001] This invention belongs to the field of airborne product technology, specifically relating to a hybrid device with ejector noise reduction and low flow resistance. Background Technology

[0002] Existing mixing devices are split designs, and are long and heavy, which cannot meet the requirements of injection, noise reduction, and low flow resistance that a mixing device needs to have under extremely limited space design constraints.

[0003] The mixing unit uses engine bleed air for hot air and an evaporator fan in the evaporative cycle system for cold air. The evaporator fan is extremely sensitive to upstream and downstream loads; the integrated ejector and the flow field after the hot and cold air mix all constitute loads on the fan, significantly affecting its performance. Simultaneously, the mixing distance between the hot air and the cold air supplied by the fan is short, making it crucial to disperse the hot air effectively. As a high-speed rotating electromechanical device, the evaporator fan has extremely stringent reliability requirements. Therefore, the system's heating gas safety design necessitates integrating an ejector function into the mixing unit to ensure gas supply safety in the event of fan failure. Since the cockpit is close to the mixing unit, noise reduction is also a design requirement. Existing mixing units cannot simultaneously meet all of these requirements. Summary of the Invention

[0004] The purpose of this invention is to provide a mixing device with ejector-based noise reduction and low flow resistance. This invention features ejector functionality, low noise, thorough mixing of hot and cold air, and low flow resistance.

[0005] The technical solution of the present invention is: a mixing device with ejector noise reduction and low flow resistance, comprising a mixing duct, wherein a hot air annular cavity is embedded in the duct body near the upstream inlet of the mixing duct, the hot air annular cavity is connected to an ejector ball located on the central axis of the mixing duct via an ejector rod; the cavity wall of the hot air annular cavity embedded in the mixing duct has circumferentially distributed diversion holes, and the openings of the diversion holes face the axis of the mixing duct on the side away from the inlet of the mixing duct; the ejector ball has ejector holes distributed on it, the openings of the ejector holes facing away from the inlet of the mixing duct, and the openings are parallel to the central axis of the mixing duct.

[0006] In the aforementioned mixing device with ejector noise reduction and low flow resistance, the diversion orifice is elliptical.

[0007] In the aforementioned mixing device with ejector noise reduction and low flow resistance, the cross-section of the ejector hole is circular.

[0008] In the aforementioned mixing device with ejector noise reduction and low flow resistance, the cavity wall of the hot air annular cavity embedded in the mixing duct has a streamlined structure, and the windward side of the streamlined structure faces the inlet of the mixing duct; the diversion holes are distributed on the leeward side of the streamlined structure.

[0009] In the aforementioned mixing device with ejector noise reduction and low flow resistance, the ejector rod has a streamlined shape, and the windward side of the streamlined structure faces the inlet of the mixing duct.

[0010] In the aforementioned mixing device with ejector noise reduction and low flow resistance, the number of flow dividers is 11.

[0011] In the aforementioned mixing device with ejector noise reduction and low flow resistance, the number of ejector holes is 7.

[0012] In the aforementioned mixing device with ejector noise reduction and low flow resistance, the structure at the downstream outlet transition of the mixing duct is designed to mimic the aircraft structure and is changed from a cylindrical shape to an irregular shape.

[0013] In the aforementioned mixing device with ejector noise reduction and low flow resistance, the cavity wall embedded in the mixing duct body and the exposed cavity wall of the hot air annular cavity are set separately.

[0014] In the aforementioned mixing device with ejector noise reduction and low flow resistance, the air inlet of the hot air annular cavity is equipped with a high-temperature bellows.

[0015] The advantages of this invention are: the mixing device of this invention has an integrated structural design, which reduces the product's structural size and weight.

[0016] This invention utilizes a streamlined design for the hot air venting pipe, separate internal and external streamlined structures, a streamlined ejector venting pipe, and a spherical structure at the tail, effectively reducing air resistance. Form drag arises from fluid detachment from an object's surface and the resulting eddies. The relationship between frictional drag and form drag, like the two component drag values, depends on the object's shape and its state in the fluid (angle of attack, angle of slip), its surface roughness, Reynolds number, and the degree and scale of oncoming turbulence. For objects with poor streamline, their frictional drag is minimal compared to their total oncoming drag; however, for objects with good streamline, the magnitude of their frictional drag can be comparable to their form drag. Therefore, the built-in streamlined section of this invention exhibits minimal fluid resistance, accounting for a very small proportion of the evaporator fan load. The relationship between the frontal drag coefficient and the Reynolds number of the spherical structure at the tail of the ejector of this invention is very complex. After extensive analysis and testing by the inventors, the frontal drag coefficient remains almost stable starting from Re = 106. When the evaporator fan supplies air, the Reynolds number is greater than 106, so its drag is small and tends to be stable.

[0017] The noise reduction and mixing design of this invention has openings in the streamlined part of the mixing device, and hot air dispersing holes are opened on the leeward side of the ejector tail sphere (the opening direction is opposite to the direction of the cold air provided by the evaporator fan). This can effectively disperse the engine bleed air into tiny streams. The airflow noise increases exponentially with the fluid mass. After dispersing the large mass fluid into tiny streams, the airflow noise is effectively reduced, and the mixing of hot and cold air can be achieved.

[0018] The downstream outlet structure of the mixing device of the present invention is designed with contouring, and the cylindrical shape is changed to an irregular shape. With the increase in size, the effect of uniform mixing of hot and cold air is further improved.

[0019] This invention employs a high-temperature pipeline compensation design using metal bellows, which greatly compensates for dimensional errors in the three axes of the aircraft's thermal air valve.

[0020] The present invention provides a drain pipe at the outlet of the mixing device, which is the lowest point of the system. The drain pipe is connected to the machine to effectively drain the condensate from the system.

[0021] The mixing device of this invention is wrapped with an insulation layer, which can effectively reduce noise and prevent heat insulation and condensation. Attached Figure Description

[0022] Figure 1 This is a schematic diagram of the overall structure of the present invention;

[0023] Figure 2 for Figure 1 View from direction A;

[0024] Figure 3 This is a schematic diagram of the internal structure of the present invention.

[0025] Reference numerals: 1-Mixing duct, 2-Hot air annular cavity, 3-Ejector rod, 4-Ejector ball, 5-Diverter hole, 6-Ejector hole, 7-Inlet port, 8-High temperature corrugated pipe, 9-Insulation layer, 10-Drain pipe, 11-Branch outlet I, 12-Branch outlet II. Detailed Implementation

[0026] The present invention will be further described below with reference to the accompanying drawings and embodiments, but this should not be construed as limiting the present invention.

[0027] Example 1. A mixing device with ejector noise reduction and low flow resistance, configured as follows: Figure 1-3As shown, the system includes a mixing duct 1, with a hot air annular cavity 2 embedded in the duct body near the upstream inlet. The hot air annular cavity 2 is connected to an ejector ball 4 located on the central axis of the mixing duct 1 via an ejector rod 3. Diverting holes 5 are distributed circumferentially on the cavity wall of the hot air annular cavity 2 embedded in the mixing duct 1, and the openings of the diverting holes 5 face the axis of the mixing duct 1 on the side away from the inlet of the mixing duct 1. The ejector ball 4 has ejector holes 6 distributed on it, with the openings of the ejector holes 6 facing away from the inlet of the mixing duct 1 and parallel to the central axis of the mixing duct 1.

[0028] The aforementioned diversion hole 5 is elliptical in shape.

[0029] The aforementioned ejector hole 6 has a circular cross-section.

[0030] The aforementioned hot air annular cavity 2 is embedded in the mixing duct 1, and the cavity wall has a streamlined structure. The windward side of the streamlined structure faces the inlet of the mixing duct 1. The diversion holes 5 are distributed on the leeward side of the streamlined structure.

[0031] The aforementioned ejector rod 3 has a streamlined shape, with the windward side of the streamlined structure facing the inlet of the mixing duct 1.

[0032] The aforementioned number of diversion holes 5 is 11.

[0033] The aforementioned ejector holes 6 number 7.

[0034] The structure at the downstream outlet transition of the aforementioned hybrid duct 1 is designed to mimic the shape of the aircraft structure, and the cylindrical shape is changed to an irregular shape.

[0035] The aforementioned hot air annular cavity 2 is embedded in the mixing duct 1 and the exposed cavity wall are set separately.

[0036] The air inlet 7 of the aforementioned hot air annular cavity 2 is equipped with a high-temperature bellows 8.

[0037] The aforementioned mixed air duct 1 is surrounded by an insulation layer 9.

[0038] The downstream outlet of the aforementioned mixed air duct 1 is equipped with a drain pipe 10.

[0039] When the air is mixed and cooled, the hot air ring cavity 2 receives the high-temperature bleed air from the engine through the air intake interface 7, and then sprays it out through the diversion hole 5 and the ejector hole 6 respectively, which are evenly distributed in the body of the mixing air duct 1. The cold air provided by the evaporator blower is blown in from the upstream inlet of the mixing air duct 1 and mixed with the evenly distributed high-temperature bleed air. After mixing, it flows out from the downstream outlet of the mixing air duct 1.

[0040] The structure of this invention has the following characteristics:

[0041] The integrated design incorporates the ejector and mixing device.

[0042] The hot air annular cavity 2 in the mixing device is designed with a streamlined shape.

[0043] The hot air annular cavity 2 in the mixing device has a streamlined structure with separate inner and outer parts.

[0044] The upper part of the integrated ejector structure has a streamlined design, while the tail part has a spherical structure.

[0045] The noise reduction and hybrid design incorporates a streamlined structure with openings in the hybrid device. The tail end of the ejector sphere has hot air ejection holes on its leeward side, facing away from the direction of the cold air supplied by the evaporator fan.

[0046] The structure at the downstream outlet transition of the mixing unit is designed to mimic the shape of the aircraft structure, and the cylindrical shape is changed to an irregular shape to increase the flow area.

[0047] The mixing unit incorporates a metal corrugated pipe in its hot air path for high-temperature pipeline compensation design.

[0048] Example 2. Triaxial displacement compensation of ±10mm in X, Y, and Z axes is achieved through a high-temperature bellows 8 to achieve high-temperature hot gas shut-off.

[0049] The streamlined design of the hot air annular cavity 2 and the hot air path of the ejector rod 3, as well as the ball head design of the ejector ball 4, can achieve a flow resistance of less than 200Pa, effectively supporting the load design of the cooling fan.

[0050] The hot air annular cavity 2 has 11 elliptical holes inside the mixing device, and the ejector ball 4 has 7 circular holes on its cold air-facing side. This effectively disperses the hot air and reduces airflow noise, and enhances the mixing effect when mixed with the cold air delivered by the evaporator fan connected to the upstream inlet of the mixing duct. According to tests, this invention can achieve a mixing temperature difference of 8°C at branch outlet I 11 and branch outlet II 12, and the noise of the mixing device is only 89 decibels. Furthermore, the downstream outlet transition structure is designed to mimic the aircraft structure, changing from a cylindrical shape to an irregular shape (see [reference]). Figure 1 The downstream outlet location increases the mixing area and further enhances the mixing effect.

[0051] The hot air annular cavity 2 has 11 elliptical holes inside the mixing device, and the ejector ball 4 has 7 circular holes on its back side facing the cold air, achieving an ejection effect of 0.42. This ensures safe gas usage downstream at no more than 120°C under cold path conditions of 10°C and hot path conditions of 154°C. Furthermore, the ejector rod is streamlined, effectively reducing fluid resistance.

[0052] The mixing device of the present invention can effectively achieve uniform mixing of hot and cold air within a 300mm length space.

[0053] The drain pipe 10 has an inner diameter of 10mm and is located at the lowest point of the device, which can effectively drain condensate.

[0054] The insulation layer 9 uses pre-oxidized fiber aerogel felt, which has a thermal conductivity of less than 0.026W / mK, and can effectively achieve heat insulation, noise reduction and condensation prevention.

Claims

1. A hybrid device with ejection muffling and low flowage resistance, characterized by, The system includes a mixing duct (1), with a hot air annular cavity (2) embedded in the duct body near the upstream inlet. The hot air annular cavity (2) is connected to an ejector ball (4) located on the central axis of the mixing duct (1) via an ejector rod (3). The hot air annular cavity (2) is embedded in the cavity wall of the mixing duct (1) with circumferentially distributed diversion holes (5), and the openings of the diversion holes (5) face the axis of the mixing duct (1) on the side away from the inlet of the mixing duct (1). The ejector ball (4) is provided with ejector holes (6), the openings of which face away from the inlet of the mixing duct (1) and are parallel to the central axis of the mixing duct (1).

2. The hybrid device with low flow resistance and sound attenuation according to claim 1, characterized in that The diversion hole (5) is elliptical.

3. The hybrid device with low flow resistance and sound attenuation according to claim 1, wherein, The ejector hole (6) has a circular cross-section.

4. The hybrid device with low flow resistance and sound attenuation according to claim 1, wherein, The hot air annular cavity (2) is embedded in the mixing duct (1) with a streamlined structure on its cavity wall. The windward side of the streamlined structure faces the inlet of the mixing duct (1). The diversion holes (5) are distributed on the leeward side of the streamlined structure.

5. The mixing device with ejector noise reduction and low flow resistance according to claim 1, characterized in that, The ejector rod (3) has a streamlined shape, and the windward side of the streamlined structure faces the inlet of the mixing duct (1).

6. The mixing device with ejector noise reduction and low flow resistance according to claim 1, characterized in that, The number of diversion holes (5) is 11.

7. The mixing device with ejector noise reduction and low flow resistance according to claim 1, characterized in that, The number of ejector holes (6) is 7.

8. The mixing device with ejector noise reduction and low flow resistance according to claim 1, characterized in that, The structure at the downstream outlet transition of the mixed air duct (1) is designed to mimic the shape of the aircraft structure and is changed from a cylindrical shape to an irregular shape.

9. The mixing device with ejector noise reduction and low flow resistance according to claim 1, characterized in that, The hot air annular cavity (2) is embedded in the mixing duct (1). The cavity wall of the duct body and the exposed cavity wall are set separately.

10. The mixing device with ejector noise reduction and low flow resistance according to claim 1, characterized in that, The air inlet (7) of the hot air annular cavity (2) is equipped with a high-temperature bellows (8).

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