Design method of multi-swirl composite nozzle of aero-engine combustion chamber

Abstract

The application belongs to the technical field of aero-engine combustion chamber multi-swirl composite nozzle design, and particularly relates to a design method of an aero-engine combustion chamber multi-swirl composite nozzle, which is characterized by complex structure, numerous parameters to be designed, scientific planning of the design process, reduction of the number of repeated iterations in the design process, shortening of the design cycle, and quick obtaining of multi-swirl composite nozzle structure parameters meeting the requirements.

Description

Technical Field

[0001] This application belongs to the technical field of multi-swirling composite nozzle design for aero-engine combustion chambers, and specifically relates to a design method for a multi-swirling composite nozzle for aero-engine combustion chambers. Background Technology

[0002] To reduce pollutant emissions under high fuel-air ratio conditions, aero engines employ multi-swirling composite nozzles to supply fuel to the combustion chamber, enhancing atomization and mixing. These nozzles mainly consist of centrifugal nozzles, air atomizing nozzles, and their piping. The structure is complex, requiring numerous design parameters. Currently, there is a lack of scientific and standardized design methods, resulting in extensive iterations and long design cycles for multi-swirling composite nozzles, making it difficult to obtain a design that meets the requirements.

[0003] This application is made in view of the aforementioned technical deficiencies.

[0004] It should be noted that the above background information is only used to assist in understanding the inventive concept and technical solution of this invention, and it does not necessarily belong to the prior art of this application. In the absence of clear evidence that the above information was disclosed on the filing date of this application, the above background information should not be used to evaluate the novelty and inventiveness of this application. Summary of the Invention

[0005] The purpose of this application is to provide a design method for a multi-swirling composite nozzle in an aero-engine combustion chamber, in order to overcome or mitigate at least one of the known technical defects.

[0006] The technical solution of this application is:

[0007] A design method for a multi-swirling composite nozzle in an aero-engine combustion chamber includes:

[0008] The performance design of the centrifugal nozzle is carried out as follows:

[0009] Calculate the effective section modulus of the centrifugal nozzle: Where α1 is the fuel atomization cone angle of the centrifugal nozzle; e1 is the effective section coefficient of the centrifugal nozzle.

[0010] Calculate the geometric characteristic coefficients of the centrifugal nozzle: Where A1 is the geometric characteristic coefficient of the centrifugal nozzle;

[0011] Calculate the flow coefficient of the centrifugal nozzle: Where μ1 is the centrifugal nozzle flow coefficient;

[0012] Calculate the nozzle area of ​​the centrifugal nozzle: Among them, A c1 Q is the orifice area of ​​the centrifugal nozzle.f1 For the fuel flow rate of the centrifugal nozzle, ΔP f1 The differential pressure supplied to the centrifugal nozzle can be determined by combining the fuel flow rate at the design point, the atomizing cone angle, and the atomized particle size, ρ. f The density of fuel;

[0013] Calculate the radius of the centrifugal nozzle: Among them, R c1 The radius of the centrifugal nozzle;

[0014] Calculate the swirl radius of the centrifugal nozzle: R S1 =(2~4)R c1 , where R S1 The swirl radius of the centrifugal nozzle;

[0015] Calculate the area of ​​the swirl channel in the centrifugal nozzle: Among them, A d1 N is the area of ​​the centrifugal nozzle swirl channel. d1 This refers to the number of swirl channels in the centrifugal nozzle;

[0016] The performance design of the air swirl nozzle is carried out as follows:

[0017] Calculate the effective section modulus of the air swirl nozzle: Where α2 is the fuel atomization cone angle of the air swirl nozzle; e2 is the effective section coefficient of the air swirl nozzle orifice;

[0018] Calculate the geometric characteristic coefficients of the air swirl nozzle: Where A2 is the geometric characteristic coefficient of the air swirl nozzle;

[0019] Calculate the flow coefficient of the air swirl nozzle: Where μ2 is the air swirl nozzle flow coefficient;

[0020] Calculate the nozzle area of ​​the air swirl nozzle: Among them, A c2 Q is the nozzle area of ​​the air swirl nozzle. f2 For the fuel flow rate of the air swirl nozzle, ΔP f2 The differential pressure supplied to the air swirl nozzle can be determined by combining the fuel flow rate at the design point, the atomization cone angle, and the atomized particle size, ρ. f The density of fuel;

[0021] Calculate the nozzle radius of the air swirl nozzle: Among them, R c2 The radius of the air swirl nozzle;

[0022] Calculate the swirl radius of the air swirl nozzle: R S2 =(2~4)R c2 , where R S2The swirl radius of the air swirl nozzle;

[0023] Calculate the swirl groove area of ​​the air swirl nozzle: Among them, A d2 N is the area of ​​the swirl groove in the air swirl nozzle. d2 This represents the number of swirl channels in the air swirling nozzle.

[0024] The performance design of the nozzle piping is carried out as follows:

[0025] Calculate the inner diameter of the nozzle piping:

[0026] in,

[0027] ΔP is the pressure loss in the nozzle pipeline;

[0028] L is the length of the nozzle pipeline;

[0029] ρ f The density of fuel;

[0030] V f This refers to the fuel flow rate within the nozzle line;

[0031] Re is the Reynolds number for the nozzle pipeline;

[0032] d is the inner diameter of the nozzle pipe;

[0033] The performance of the centrifugal nozzle was verified, specifically as follows:

[0034] Calculate the geometric characteristic number A1 of the centrifugal nozzle: Where β1 is the tilt angle of the swirl channel of the centrifugal nozzle;

[0035] Calculate the effective section modulus e1 of the centrifugal nozzle:

[0036] Calculate the fuel atomization cone angle α1 of the centrifugal nozzle:

[0037] Calculate the centrifugal nozzle flow coefficient μ1:

[0038] Calculate the fuel flow rate Q of the centrifugal nozzle f1 :

[0039] If the fuel atomization cone angle of the centrifugal nozzle is α1 and the fuel flow rate of the centrifugal nozzle is Q f1 If the design requirements are not met, the performance scheme of the centrifugal nozzle will be redesigned.

[0040] The performance of the air swirl nozzle was verified, specifically as follows:

[0041] Calculate the geometric characteristic number A2 of the air swirl nozzle: Where β2 is the tilt angle of the swirl groove of the air swirling nozzle;

[0042] Calculate the effective section modulus e2 of the air swirl nozzle:

[0043] Calculate the fuel atomization cone angle α2 of the air swirl nozzle:

[0044] Calculate the flow coefficient μ2 of the air swirl nozzle:

[0045] Calculate the fuel flow rate Q of the air swirl nozzle f2 :

[0046] If the fuel atomization cone angle α2 of the air swirl nozzle and the fuel flow rate Q of the air swirl nozzle f2 If the design requirements are not met, the performance scheme of the air swirl nozzle will be redesigned.

[0047] The performance of centrifugal nozzles, air atomizing nozzles, and nozzle pipelines is verified by simulation or testing. If the fuel atomization cone angle and fuel flow rate of centrifugal nozzles and air atomizing nozzles do not meet the design requirements, or the nozzle pipeline loss exceeds the limit, the performance scheme of centrifugal nozzles, air atomizing nozzles, and nozzle pipelines shall be redesigned accordingly.

[0048] By combining the centrifugal nozzle, air atomizing nozzle, and nozzle pipeline into a single unit, the specific structure of the multi-swirling composite nozzle for the combustion chamber of an aero-engine is obtained, and the design is completed.

[0049] Optionally, in the above-mentioned design method for multi-swirling composite nozzles in aero-engine combustion chambers, the design point for centrifugal nozzles is taken as the idle speed and below operating conditions.

[0050] The operating point of the aircraft engine at takeoff is taken as the design point of the air swirl nozzle.

[0051] The operating point of the aircraft engine at takeoff is taken as the design point of the nozzle pipeline.

[0052] Optionally, in the above-mentioned design method for multi-swirling composite nozzles in aero-engine combustion chambers, when designing the performance scheme of the nozzle pipeline, the fuel flow velocity V within the nozzle pipeline is... f Take 8-10 m / s. Attached Figure Description

[0053] Figure 1 This is a schematic diagram of the multi-swirling composite nozzle design method for aero-engine combustion chambers provided in this application embodiment. Detailed Implementation

[0054] To make the technical solution and advantages of this application clearer, the technical solution of this application will be described in a clearer and more complete manner below with reference to the accompanying drawings. It should be understood that the specific embodiments described herein are only some embodiments of this application, and are only used to explain this application, not to limit this application. It should be noted that, for ease of description, only the parts related to this application are shown in the accompanying drawings. Other related parts can be referred to the general design. In the absence of conflict, the embodiments and technical features in the embodiments of this application can be combined with each other to obtain new embodiments.

[0055] Furthermore, unless otherwise defined, the technical or scientific terms used in this application description shall have the ordinary meaning understood by one of ordinary skill in the art to which this application pertains. The terms "upper," "lower," "left," "right," "center," "vertical," "horizontal," "inner," and "outer," etc., used in this application description to indicate relative direction or positional relationship are used only to indicate relative orientation or positional relationship, and do not imply that the device or component must have a specific orientation, or be constructed and operated in a specific orientation. When the absolute position of the described object changes, its relative positional relationship may also change accordingly, and therefore should not be construed as a limitation on this application. The terms "first," "second," "third," and similar terms used in this application description are used only for descriptive purposes to distinguish different components, and should not be construed as indicating or implying relative importance. The terms "a," "one," or "the," etc., used in this application description should not be construed as an absolute limitation on quantity, but should be construed as indicating the existence of at least one. The terms "including," "comprising," etc., used in this application description mean that the element or object preceding the word covers the element or object listed after the word and its equivalents, without excluding other elements or objects.

[0056] Furthermore, it should be noted that, unless otherwise explicitly specified and limited, terms such as “installation,” “connection,” and “linkage” used in the description of this application should be interpreted broadly. For example, a connection can be a fixed connection, a detachable connection, or an integral connection; it can be a mechanical connection or an electrical connection; it can be a direct connection or an indirect connection through an intermediate medium; or it can be a connection within two components. Those skilled in the art can understand its specific meaning in this application according to the specific circumstances.

[0057] The following is in conjunction with the appendix Figure 1 This application will be described in further detail.

[0058] The design of a multi-swirling composite nozzle for an aero-engine combustion chamber involves inputs such as fuel supply pressure, fuel flow rate, atomized particle size, atomization cone angle under typical aero-engine operating conditions, as well as combustion chamber inlet air temperature, pressure, flow rate, fuel characteristics, fuel temperature, maximum and minimum fuel supply pressure limits of the fuel supply system, air swirler flow distribution, and nozzle interface dimensions.

[0059] The design method for multi-swirling composite nozzles in aero-engine combustion chambers provided in this application addresses the complex structure and numerous parameters required for design of multi-swirling composite nozzles. By scientifically planning the design process, it can reduce the number of iterations and shorten the design cycle, quickly obtaining the structural parameters of multi-swirling composite nozzles that meet the requirements. The method mainly includes performance scheme design, performance verification, component-level scheme verification, and integrated structure design steps.

[0060] I. The performance scheme design steps include the performance scheme design of centrifugal nozzles, air atomizing nozzles, and nozzle pipelines.

[0061] The performance design of the centrifugal nozzle was carried out. Considering that the atomization quality of the centrifugal nozzle has a significant impact on the ignition and flameout performance of the combustion chamber at idle speed and below, the design point of the centrifugal nozzle was taken as the idle speed and below operating condition. The specific design is as follows:

[0062] Calculate the effective section modulus of the centrifugal nozzle: Where α1 is the fuel atomization cone angle of the centrifugal nozzle; e1 is the effective section coefficient of the centrifugal nozzle.

[0063] Calculate the geometric characteristic coefficients of the centrifugal nozzle: Where A1 is the geometric characteristic coefficient of the centrifugal nozzle;

[0064] Calculate the flow coefficient of the centrifugal nozzle: Where μ1 is the centrifugal nozzle flow coefficient;

[0065] Calculate the nozzle area of ​​the centrifugal nozzle: Among them, A c1 Q is the orifice area of ​​the centrifugal nozzle. f1 For the fuel flow rate of the centrifugal nozzle, ΔP f1 The differential pressure supplied to the centrifugal nozzle can be determined by combining the fuel flow rate at the design point, the atomizing cone angle, and the atomized particle size, ρ. f The density of fuel;

[0066] Calculate the radius of the centrifugal nozzle: Among them, R c1 The radius of the centrifugal nozzle;

[0067] Calculate the swirl radius of the centrifugal nozzle: R S1 =K*Rc1 , where R S1 K is the swirl radius of the centrifugal nozzle, which can be taken as 2 to 4. In specific applications, it can be taken as 3.

[0068] Calculate the area of ​​the swirl channel in the centrifugal nozzle: Among them, A d1 N is the area of ​​the centrifugal nozzle swirl channel. d1 This represents the number of swirl channels in the centrifugal nozzle.

[0069] The performance design of the air swirl nozzle is carried out, taking the operating condition point of the aero-engine during takeoff as the design point of the air swirl nozzle. The specific design is as follows:

[0070] Calculate the effective section modulus of the air swirl nozzle: Where α2 is the fuel atomization cone angle of the air swirl nozzle; e2 is the effective section coefficient of the air swirl nozzle orifice;

[0071] Calculate the geometric characteristic coefficients of the air swirl nozzle: Where A2 is the geometric characteristic coefficient of the air swirl nozzle;

[0072] Calculate the flow coefficient of the air swirl nozzle: Where μ2 is the air swirl nozzle flow coefficient;

[0073] Calculate the nozzle area of ​​the air swirl nozzle: Among them, A c2 Q is the nozzle area of ​​the air swirl nozzle. f2 For the fuel flow rate of the air swirl nozzle, ΔP f2 The differential pressure supplied to the air swirl nozzle can be determined by combining the fuel flow rate at the design point, the atomization cone angle, and the atomized particle size, ρ. f The density of fuel;

[0074] Calculate the nozzle radius of the air swirl nozzle: Among them, R c2 The radius of the air swirl nozzle;

[0075] Calculate the swirl radius of the air swirl nozzle: R S2 =K*R c2 , where R S2 The swirl radius of the air swirl nozzle, K can be taken as 2 to 4, and can be taken as 3 in specific applications;

[0076] Calculate the swirl groove area of ​​the air swirl nozzle: Among them, A d2 N is the area of ​​the swirl groove in the air swirl nozzle. d2 This represents the number of swirl channels in the air swirling nozzle.

[0077] The performance design of the nozzle piping was carried out, taking the operating point of the aero-engine during takeoff as the design point for the air swirling nozzle. The specific design is as follows:

[0078] Calculate the inner diameter of the nozzle piping:

[0079] in,

[0080] ΔP is the pressure loss in the nozzle pipeline;

[0081] L is the length of the nozzle pipeline;

[0082] ρ f The density of fuel;

[0083] V f The fuel flow velocity in the nozzle line is generally taken as 8 to 10 m / s;

[0084] Re is the Reynolds number for the nozzle pipeline;

[0085] d represents the inner diameter of the nozzle pipe. Generally speaking, a larger inner diameter of the nozzle pipe will inevitably require a corresponding increase in the diameter of the nozzle rod, which will affect the airflow at the diffuser outlet and increase the total pressure loss in the combustion chamber. If the inner diameter of the nozzle pipe is too small, the oil pressure loss will increase sharply. The inner diameter of the nozzle pipe should be reduced as much as possible while avoiding excessive oil pressure loss.

[0086] II. The performance verification steps include the performance verification of centrifugal nozzles and air atomizing nozzles.

[0087] The specific performance verification of the centrifugal nozzle is as follows:

[0088] Calculate the geometric characteristic number A1 of the centrifugal nozzle: Where β1 is the tilt angle of the swirl channel of the centrifugal nozzle;

[0089] Calculate the effective section modulus e1 of the centrifugal nozzle:

[0090] Calculate the fuel atomization cone angle α1 of the centrifugal nozzle:

[0091] Calculate the centrifugal nozzle flow coefficient μ1:

[0092] Calculate the fuel flow rate Q of the centrifugal nozzle f1 :

[0093] If the fuel atomization cone angle of the centrifugal nozzle is α1 and the fuel flow rate of the centrifugal nozzle is Q f1 If the design requirements are not met, the performance scheme of the centrifugal nozzle needs to be redesigned.

[0094] The specific performance verification of the air swirl nozzle is as follows:

[0095] Calculate the geometric characteristic number A2 of the air swirl nozzle: Where β2 is the tilt angle of the swirl groove of the air swirling nozzle;

[0096] Calculate the effective section modulus e2 of the air swirl nozzle:

[0097] Calculate the fuel atomization cone angle α2 of the air swirl nozzle:

[0098] Calculate the flow coefficient μ2 of the air swirl nozzle:

[0099] Calculate the fuel flow rate Q of the air swirl nozzle f2 :

[0100] If the fuel atomization cone angle α2 of the air swirl nozzle and the fuel flow rate Q of the air swirl nozzle f2 If the design requirements are not met, the performance scheme of the air swirl nozzle needs to be redesigned.

[0101] III. Component-level solution verification steps: Verify the performance of centrifugal nozzles, air atomizing nozzles, and nozzle pipelines using simulation or experimental methods. If the fuel atomization cone angle and fuel flow rate of centrifugal nozzles and air atomizing nozzles do not meet the design requirements, or if the nozzle pipeline loss exceeds the limit value (which can be determined by referring to the smaller value of the loss), then the performance solution of centrifugal nozzles, air atomizing nozzles, and nozzle pipelines should be redesigned.

[0102] Fourth, combine the centrifugal nozzle, air atomizing nozzle, and nozzle pipeline into a whole, ensuring that the dimensions of each interface meet the design input requirements, to obtain the specific structure of the multi-swirling composite nozzle for the aero-engine combustion chamber, complete the design, and output the results.

[0103] The technical solution of this application has been described in conjunction with the preferred embodiments shown in the accompanying drawings. Those skilled in the art should understand that the scope of protection of this application is obviously not limited to these specific embodiments. Without departing from the principles of this application, those skilled in the art can make equivalent changes or substitutions to the relevant technical features, and the technical solutions after these changes or substitutions will all fall within the scope of protection of this application.

Claims

1. A design method for a multi-swirling composite nozzle in an aero-engine combustion chamber, characterized in that, include: The performance design of the centrifugal nozzle is carried out as follows: Calculate the effective section modulus of the centrifugal nozzle: Where α1 is the fuel atomization cone angle of the centrifugal nozzle; e1 is the effective section coefficient of the centrifugal nozzle. Calculate the geometric characteristic coefficients of the centrifugal nozzle: Where A1 is the geometric characteristic coefficient of the centrifugal nozzle; Calculate the flow coefficient of the centrifugal nozzle: Where μ1 is the centrifugal nozzle flow coefficient; Calculate the nozzle area of ​​the centrifugal nozzle: Among them, A c1 Q is the orifice area of ​​the centrifugal nozzle. f1 For the centrifugal nozzle fuel flow rate, ΔP f1 The differential pressure supplied to the centrifugal nozzle can be determined by combining the fuel flow rate at the design point, the atomizing cone angle, and the atomized particle size, ρ. f The density of fuel; Calculate the radius of the centrifugal nozzle: Among them, R c1 The radius of the centrifugal nozzle; Calculate the swirl radius of the centrifugal nozzle: R S1 =(2~4)R c1 , where R S1 The swirl radius of the centrifugal nozzle; Calculate the area of ​​the swirl channel in the centrifugal nozzle: Among them, A d1 N is the area of ​​the centrifugal nozzle swirl channel. d1 This refers to the number of swirl channels in the centrifugal nozzle; The performance design of the air swirl nozzle is carried out as follows: Calculate the effective section modulus of the air swirl nozzle: Where α2 is the fuel atomization cone angle of the air swirl nozzle; e2 is the effective section coefficient of the air swirl nozzle orifice; Calculate the geometric characteristic coefficients of the air swirl nozzle: Where A2 is the geometric characteristic coefficient of the air swirl nozzle; Calculate the flow coefficient of the air swirl nozzle: Where μ2 is the air swirl nozzle flow coefficient; Calculate the nozzle area of ​​the air swirl nozzle: Among them, A c2 Q is the nozzle area of ​​the air swirl nozzle. f2 For the fuel flow rate of the air swirl nozzle, ΔP f2 The differential pressure supplied to the air swirl nozzle can be determined by combining the fuel flow rate at the design point, the atomization cone angle, and the atomized particle size, ρ. f The density of fuel; Calculate the nozzle radius of the air swirl nozzle: Among them, R c2 The radius of the air swirl nozzle; Calculate the swirl radius of the air swirl nozzle: R S2 =(2~4)R c2 , where R S2 The swirl radius of the air swirl nozzle; Calculate the swirl groove area of ​​the air swirl nozzle: Among them, A d2 N is the area of ​​the swirl groove in the air swirl nozzle. d2 The number of swirl slots in the air swirl nozzle; The performance design of the nozzle piping is carried out as follows: Calculate the inner diameter of the nozzle piping: in, ΔP is the pressure loss in the nozzle pipeline; L is the length of the nozzle pipeline; ρ f The density of fuel; V f This refers to the fuel flow rate within the nozzle line; Re is the Reynolds number for the nozzle pipeline; d is the inner diameter of the nozzle pipe; The performance of the centrifugal nozzle was verified, specifically as follows: Calculate the geometric characteristic number A1 of the centrifugal nozzle: Where β1 is the inclination angle of the swirl channel of the centrifugal nozzle; Calculate the effective section modulus e1 of the centrifugal nozzle: Calculate the fuel atomization cone angle α1 of the centrifugal nozzle: Calculate the centrifugal nozzle flow coefficient μ1: Calculate the fuel flow rate Q of the centrifugal nozzle f1 : If the fuel atomization cone angle of the centrifugal nozzle is α1 and the fuel flow rate of the centrifugal nozzle is Q f1 If the design requirements are not met, the performance scheme of the centrifugal nozzle will be redesigned. The performance of the air swirl nozzle was verified, specifically as follows: Calculate the geometric characteristic number A2 of the air swirl nozzle: Where β2 is the tilt angle of the swirl groove of the air swirling nozzle; Calculate the effective section modulus e2 of the air swirl nozzle: Calculate the fuel atomization cone angle α2 of the air swirl nozzle: Calculate the flow coefficient μ2 of the air swirl nozzle: Calculate the fuel flow rate Q of the air swirl nozzle f2 : If the fuel atomization cone angle α2 of the air swirl nozzle and the fuel flow rate Q of the air swirl nozzle f2 If the design requirements are not met, the performance scheme of the air swirl nozzle will be redesigned. The performance of centrifugal nozzles, air atomizing nozzles, and nozzle pipelines is verified by simulation or testing. If the fuel atomization cone angle and fuel flow rate of centrifugal nozzles and air atomizing nozzles do not meet the design requirements, or the nozzle pipeline loss exceeds the limit, the performance scheme of centrifugal nozzles, air atomizing nozzles, and nozzle pipelines shall be redesigned accordingly. By combining the centrifugal nozzle, air atomizing nozzle, and nozzle pipeline into a single unit, the specific structure of the multi-swirling composite nozzle for the combustion chamber of an aero-engine is obtained, and the design is completed.

2. The design method for a multi-swirling composite nozzle in an aero-engine combustion chamber according to claim 1, characterized in that, The design point for centrifugal nozzles is taken as the operating point at slow speed and below. The operating point of the aircraft engine at takeoff is taken as the design point of the air swirl nozzle. The operating point of the aircraft engine at takeoff is taken as the design point of the nozzle pipeline.

3. The design method for a multi-swirling composite nozzle in an aero-engine combustion chamber according to claim 1, characterized in that, When designing the performance scheme of the nozzle pipeline, the fuel flow velocity V in the nozzle pipeline is... f Take 8-10 m / s.

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