A nozzle area adjustable device for pre-swirl air supply system

Abstract

The present invention relates to the technical field of pre-swirl air supply systems for aircraft engines, and specifically to a nozzle area adjustable device for a pre-swirl air supply system, comprising: a plurality of air intake guide assemblies, a plurality of air intake baffles, and a drive assembly. The plurality of air intake guide assemblies are evenly distributed on the inner ring of the nozzle, and each air intake guide assembly is connected to the leading edge of the blade of a lobe-shaped pre-swirl nozzle. An air intake guide channel is formed in the air intake guide assembly, and the air intake guide channel is connected to the nozzle flow channel of the corresponding lobe-shaped pre-swirl nozzle; the air intake baffles are radially penetrated on the outer ring of the nozzle, and the air intake baffles correspond one-to-one with the air intake guide assemblies; the drive assembly is used to drive the plurality of synchronous air intake baffles into the air intake guide channel to adjust the air intake area of ​​the air intake guide channel. The present invention can effectively control the size of the total air intake area of ​​the nozzle flow channel, thereby actively controlling the amount of air bleed of the pre-swirl air supply system and improving the operating efficiency of the engine.

Description

Technical Field

[0001] The invention relates to the technical field of aero-engine pre-swirl air supply system, and in particular to a nozzle area adjustable device for a pre-swirl air supply system. Background Art

[0002] Aircraft engines are continuously developing towards the goals of high thrust-to-weight ratios and high efficiency, one of the primary approaches to achieving this is increasing turbine inlet temperatures and pressure ratios. This increased inlet temperature significantly deteriorates the operating environment of high-temperature components within the engine, leading to reduced reliability and shortened engine life. Turbine blades are effectively cooled using cooling air through rib flow cooling, impingement cooling, and film cooling. Furthermore, engine designers have developed a pre-swirl air supply system, which provides high-quality cooling air to the turbine rotor blades at the required flow and pressure, thereby reducing cooling air consumption and ensuring reliable operation of high-temperature components.

[0003] The cooling principle of the pre-swirl air supply system is to accelerate the airflow through the pre-swirl nozzle and generate a larger circumferential velocity component, thereby reducing the relative velocity between the static airflow and the rotor, thereby lowering the relative total airflow temperature. From a cooling perspective, the greater the amount of cooling air used, the better the effect. However, cooling air drawn from the compressor does not perform work in the turbine, which reduces engine thrust. Therefore, the amount of bleed air in the pre-swirl air supply system directly affects overall engine performance. The design value of the bleed air volume of the pre-swirl air supply system is generally set at the value when the turbine blades require the maximum amount of cooling air. This means that the engine has an excess of cooling air under other operating conditions. However, excessive bleed air volume can affect engine operating efficiency. Reducing the bleed air volume under off-design conditions can reduce fuel consumption and increase thrust-to-weight ratio. Therefore, actively controlling the bleed air flow rate of the pre-swirl air supply system for different aircraft engine flight conditions is crucial for improving engine operating efficiency.

[0004] In existing technology, active control of the bleed air flow in a pre-swirl air supply system involves dividing the nozzle flow path into a normally open path and an adjustable path via a partition. This method allows the adjustable path to be opened at the engine's design point, using a valve at the compressor outlet to ensure cooling air for the turbine blades. Under off-design conditions, the adjustable path can be closed to reduce cooling air. Therefore, traditional methods only have two states: an open or closed adjustable path, suitable for both design and off-design engine operating conditions. However, when an aircraft engine has multiple off-design operating conditions requiring active control of the pre-swirl air supply system's bleed air flow, this method cannot meet the cooling air requirements of the turbine blades under every operating condition.

[0005] Therefore, it is necessary to provide a nozzle area adjustable device for a pre-swirl air supply system to solve the above problems. Summary of the Invention

[0006] The present invention provides a device for adjusting the nozzle area of ​​a pre-swirl air supply system to solve the problem that the existing method has only two states of an on-off adjustable flow path, which are respectively applicable to the engine design point and non-design point operating conditions. However, when an aircraft engine has multiple non-design point operating conditions that require active control of the bleed air volume of the pre-swirl air supply system, this method cannot meet the turbine blade's demand for cooling air volume under each operating condition.

[0007] The present invention provides a nozzle area adjustable device for a pre-swirl air supply system, which adopts the following technical solutions, including:

[0008] A plurality of air intake guide assemblies are evenly distributed on the inner ring of the nozzle, and each air intake guide assembly is connected to the leading edge of a blade of a lobe hole type pre-swirl nozzle. An air intake guide channel is formed in the air intake guide assembly, and the air intake guide channel is connected to the nozzle flow channel of the corresponding lobe hole type pre-swirl nozzle;

[0009] An air intake baffle is radially arranged on the outer ring of the nozzle, and the air intake baffle corresponds to the air intake guide assembly one by one;

[0010] And a driving component is used to drive multiple air intake baffles to synchronously enter the corresponding air intake guide channels to adjust the air intake area of ​​the air intake guide channels.

[0011] Preferably, the air intake guide assembly includes: two leading edge plates, the leading edge plates are arranged on the outer peripheral surface of the inner ring of the nozzle, the ends of the leading edge plates are connected to the leading edges of the blades of the leaf hole type pre-swirl nozzle of the inner ring of the nozzle, and an air intake guide channel is formed between the two leading edge plates.

[0012] Preferably, a through slot for passing the air intake baffle is provided on the outer ring of the nozzle, and guide slots corresponding to the through slot are provided on the two leading edge plates, wherein the driving assembly is used to drive the air intake baffle to pass through the through slot and into the guide slot.

[0013] Preferably, the radial height of the leading edge plate is the same as the blade height of the hole-type pre-swirl nozzle.

[0014] Preferably, the drive assembly includes a plurality of linear motors, the plurality of linear motors are controlled and driven synchronously, and the output end of each linear motor is connected to the corresponding air intake baffle.

[0015] Preferably, there is an interference fit between the nozzle inner ring and the nozzle outer ring.

[0016] Preferably, the nozzle inner ring and the nozzle outer ring are connected by pins, and the pins are arranged in the leading edge area of ​​the nozzle inner ring.

[0017] A pre-swirl air supply system comprises a nozzle area adjustable device for the pre-swirl air supply system according to the present invention.

[0018] An aircraft engine comprises the pre-swirl air supply system of the present invention.

[0019] The beneficial effects of the present invention are:

[0020] 1. The drive assembly drives the intake baffle to move radially along the outer ring of the nozzle, so that the intake baffle enters the intake guide channel of the intake guide assembly. Since the intake guide channel is connected to the nozzle flow channel of the nozzle, the area of ​​the intake nozzle flow channel is changed. The total intake area of ​​the nozzle flow channel can be effectively controlled by multiple intake baffles, thereby actively controlling the amount of air bleed of the pre-swirl air supply system and improving the engine operating efficiency.

[0021] 2. The present invention controls the total area of ​​the pre-swirl nozzle by controlling the area of ​​the air intake channel in front of the orifice pre-swirl nozzle. This does not alter the shape and position of the nozzle's pressure and suction surfaces, thus virtually eliminating any adverse effects on the nozzle's acceleration and flow properties. This means that even when the present invention regulates the pre-swirl nozzle's intake area, the nozzle maintains high acceleration and flow properties. Within the nozzle pressure ratio range of 1.445 to 1.506, and when the present invention controls the pre-swirl nozzle's intake area between 75% and 100%, the pre-swirl nozzle's flow coefficient varies from 0.927 to 0.933, with nozzle performance fluctuations of less than 0.7%. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] In order to more clearly illustrate the embodiments of the present invention or the technical solutions in the prior art, the following briefly introduces the drawings required for use in the embodiments or the description of the prior art. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying any creative work.

[0023] Figure 1 It is a partial schematic diagram of a nozzle area adjustable device for a pre-swirl air supply system of the present invention;

[0024] Figure 2 This is a schematic structural diagram of a drive assembly and an air intake baffle for a nozzle area adjustable device for a pre-swirl air supply system according to the present invention;

[0025] Figure 3 This is a schematic diagram of the overall structure of a nozzle area adjustable device for a pre-swirl air supply system according to the present invention;

[0026] Figure 4 Schematic diagram of the structure of the nozzle inner ring in an embodiment of the present invention;

[0027] Figure 5 Schematic diagram of the structure of the nozzle outer ring in an embodiment of the present invention;

[0028] Figure 6Schematic diagram of the through groove on the outer ring of the nozzle in an embodiment of the present invention;

[0029] Figure 7 Schematic diagram of the structure of the air intake guide assembly on the inner ring of the nozzle in an embodiment of the present invention.

[0030] In the figure: 1. Leading edge plate; 2. Air intake baffle; 3. Linear motor; 4. Air intake guide channel; 5. Through slot; 6. Leaf hole pre-swirl nozzle; 7. Guide slot. DETAILED DESCRIPTION

[0031] The following will clearly and completely describe the technical solutions in the embodiments of the present invention in conjunction with the accompanying drawings. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without making creative efforts are within the scope of protection of the present invention.

[0032] An embodiment of the nozzle area adjustable device for a pre-swirl air supply system of the present invention is as follows: Figure 1 As shown, it includes: multiple air intake guide assemblies, multiple air intake baffles 2 and multiple drive assemblies. The multiple air intake guide assemblies are evenly distributed on the inner ring of the nozzle, and each air intake guide assembly is connected to the leading edge of the blade of a leaf hole type pre-swirl nozzle 6. An air intake guide channel 4 is formed in the air intake guide assembly, and the air intake guide channel 4 is connected to the nozzle flow channel of the corresponding leaf hole type pre-swirl nozzle 6; as shown Figure 3 、 Figure 4 and 5 As shown, multiple air intake baffles 2 are evenly distributed on the circumference of the nozzle outer ring, and the air intake baffles 2 are radially penetrated on the nozzle outer ring, and each air intake baffle 2 corresponds to an air intake guide assembly; multiple driving assemblies are used to synchronously drive the corresponding air intake baffles 2 into the air intake guide channel 4 to adjust the air intake area of ​​the air intake guide channel 4; the leaf hole type pre-swirl nozzle of this embodiment adopts the leaf hole type pre-swirl nozzle in patent number CN20150472608.9.

[0033] like Figure 7 As shown, the air intake guide assembly includes: two leading edge plates 1, the leading edge plates 1 are arranged on the outer peripheral surface of the inner ring of the nozzle, the ends of the leading edge plates 1 are connected to the leading edges of the blades of the lobe hole type pre-swirl nozzle 6, and an air intake guide channel 4 is formed between the two leading edge plates 1; the radial height of the leading edge plate 1 is the same as the blade height of the lobe hole type pre-swirl nozzle 6. It should be noted that the air intake guide channel 4 is connected to the nozzle flow channel opening formed by the blades of the lobe hole type pre-swirl nozzle.

[0034] like Figure 6As shown, the nozzle outer ring is provided with a through slot 5 for receiving the intake baffle 2. The shape and size of the through slot 5 are consistent with those of the intake baffle 2, ensuring that the intake baffle 2 can be inserted through the through slot 5. Several through slots 5 are evenly distributed around the circumference of the nozzle outer ring and correspond one-to-one with the guide channels 4 of the intake guide assembly. Guide grooves 7 corresponding to the through slots 5 are provided on the two leading edge plates 1. The drive assembly is used to drive the intake baffle 2 through the through slot 5 and into the guide groove 7. The length and width of the guide groove 7 are consistent with those of the intake baffle 2. Several intake guide channels 4 are evenly distributed around the outer circumference of the nozzle inner ring and correspond one-to-one with the intake baffle 2.

[0035] like Figure 2 As shown, the driving assembly includes a plurality of linear motors 3 , which are synchronously controlled and driven, and an output end of each linear motor 3 is connected to a corresponding air intake baffle 2 .

[0036] like Figure 4 and Figure 5 As shown, during the pre-swirl nozzle manufacturing process, the inner and outer rings are machined separately. Several hole-type pre-swirl nozzle blades are evenly distributed circumferentially on the inner ring, with the blade height equal to the radial height of the leading edge plate 1. Furthermore, several pin holes are evenly distributed on both the inner and outer rings, connecting them via pins. To avoid significant interference with airflow, the pin holes are located in the leading edge of the hole-type pre-swirl nozzle blades. During assembly, an interference fit of 0.1 mm is maintained between the inner and outer rings, and the outer ring is heated for assembly.

[0037] A pre-swirl air supply system comprises a nozzle area adjustable device for the pre-swirl air supply system according to the present invention.

[0038] An engine comprises the pre-swirl air supply system of the present invention.

[0039] The present invention will be described below with reference to specific embodiments:

[0040] In this embodiment, the pre-swirl nozzle inlet area is controlled for four operating points (operating point 1, operating point 2, operating point 3, and operating point 4) of a certain aircraft engine to meet the turbine blade's requirements for the pre-swirl air supply system's bleed air volume at operating points 1 to 4:

[0041] The pre-swirl nozzle inlet area, number of nozzles, nozzle radius position, and number of adjustable devices at operating points 1 to 4 are determined by the boundary conditions of the pre-swirl air supply system and the overall design of the pre-swirl. The specific system structure is: the number of nozzle rings is 24, the nozzles, receiving holes, and air supply holes are located at the same radius, the nozzle pre-swirl angle is 15°, and the pre-swirl air supply system adopts a leaf hole pre-swirl nozzle, a leaf-shaped receiving hole structure, and the cover plate cavity structure is removed. Table 1 shows the boundary conditions of the pre-swirl air supply system at operating points 1 to 4. It can be seen that due to the large differences in the system pressure ratio and total inlet temperature of the pre-swirl air supply system at operating points 1 to 4, the turbine blades have different requirements for the cooling air volume of the pre-swirl air supply system under different operating conditions, and the demand range is between 0.242kg / s and 0.655kg / s.

[0042] Table 1

[0043]

[0044] In order to actively control the bleed air volume of the pre-swirl air supply system under different working conditions and improve the operating efficiency of the aircraft engine, six nozzle area adjustable devices for the pre-swirl air supply system of the present invention are evenly installed circumferentially on the nozzle ring. Table 2 shows the nozzle inlet area, bleed air volume of the pre-swirl air supply system, nozzle flow coefficient and temperature drop efficiency of the pre-swirl air supply system at working points 1 to 4 obtained by CFD numerical simulation. It can be seen from Mark 2 that the nozzle area adjustable device for the pre-swirl air supply system of this embodiment can flexibly adjust the nozzle inlet area according to different working conditions of the pre-swirl air supply system, so that the bleed air volume just meets the cooling air volume demand of the turbine blades for the pre-swirl air supply system under different working conditions, thereby realizing that the pre-swirl air supply system can actively control the size of the bleed air volume under different working conditions and improve the operating efficiency of the engine. In addition, the present invention has almost no effect on the temperature drop performance and flow performance of the pre-swirling air supply system during operation. When the pre-swirling air supply system is at operating points 1 to 4 (the system pressure ratio range is 1.44 to 1.52), the nozzle flow coefficient maintains a relatively high level of 0.927 to 0.933, and the system temperature drop is between 40.44K and 63.01K, which is higher than the overall temperature drop level of the current pre-swirling air supply system.

[0045] Table 2

[0046]

[0047] How it works

[0048] When in use, according to the air intake demand, multiple linear motors 3 are synchronously controlled to work, and the linear motors 3 drive the air intake baffle 2 to block the air intake guide channel 4, thereby adjusting the area of ​​the nozzle flow channel.

[0049] The above description is only a preferred embodiment of the present invention and is 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 in the scope of protection of the present invention.

Claims

1. A nozzle area adjustable device for a pre-swirl air supply system, characterized in that: include: A plurality of air intake guide assemblies are evenly distributed on the inner ring of the nozzle, and each air intake guide assembly is connected to the leading edge of a blade of a leaf hole type pre-swirl nozzle (6), an air intake guide channel (4) is formed in the air intake guide assembly, and the air intake guide channel (4) is connected to the nozzle flow channel of the corresponding leaf hole type pre-swirl nozzle (6); An air intake baffle (2) is radially arranged on the outer ring of the nozzle, and the air intake baffle (2) corresponds to the air intake guide assembly one by one; And a driving assembly for driving the plurality of air intake baffles (2) to synchronously enter the corresponding air intake guide channels (4) to adjust the air intake area of ​​the air intake guide channels (4).

2. The nozzle area adjustable device for a pre-swirl air supply system according to claim 1, characterized in that: The air intake guide assembly comprises: two leading edge plates (1), the leading edge plates (1) being arranged on the outer peripheral surface of the nozzle inner ring, the ends of the leading edge plates (1) being connected to the leading edges of the blades of the leaf hole type pre-swirl nozzle (6) of the nozzle inner ring, and an air intake guide channel (4) being formed between the two leading edge plates (1).

3. The nozzle area adjustable device for a pre-swirl air supply system according to claim 2, characterized in that: A through slot (5) for passing the air intake baffle (2) is provided on the outer ring of the nozzle, and guide slots (7) corresponding to the through slot (5) are provided on the two leading edge plates (1), wherein the drive assembly is used to drive the air intake baffle (2) to pass through the through slot (5) and enter the guide slot (7).

4. The nozzle area adjustable device for a pre-swirl air supply system according to claim 2, characterized in that: The radial height of the leading edge plate (1) is the same as the blade height of the leaf hole type pre-swirl nozzle (6).

5. The nozzle area adjustable device for a pre-swirl air supply system according to claim 1, characterized in that: The drive assembly comprises a plurality of linear motors (3), the plurality of linear motors (3) are synchronously controlled and driven, and the output end of each linear motor (3) is connected to the corresponding air intake baffle (2).

6. The nozzle area adjustable device for a pre-swirl air supply system according to claim 1, characterized in that: There is interference fit between the nozzle inner ring and the nozzle outer ring.

7. The nozzle area adjustable device for a pre-swirl air supply system according to claim 1, characterized in that: The nozzle inner ring and the nozzle outer ring are connected by pins, and the pins are arranged in the leading edge area of ​​the nozzle inner ring.

8. A pre-swirl air supply system, characterized in that: The invention comprises a nozzle area adjustable device for a pre-swirl air supply system as described in any one of claims 1 to 7.

9. An aircraft engine, characterized in that: Including the pre-swirl air supply system according to claim 8.

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