Air system design method for an aeroengine

Abstract

The application provides an air system design method for an aero-engine, comprising the following steps: S1, according to the basic size D of a throttling element output by an air system preliminary design scheme, the tolerance data of the throttling element is subjected to a normal distribution; S2, the sensitivity coefficient matrix of each result parameter y of the air system to each throttling element design size parameter b is sorted out; S3, according to the sensitivity analysis result of each element, the given preliminary element tolerance is divided into multiple types; S4, based on the multiple types of element tolerances, targeted design adjustment is carried out; S5, according to the adjusted tolerance range, whether the adjusted tolerance range meets the air system probability requirement is judged; if yes, the adjusted tolerance parameter is output; if not, the steps S2 to S4 are repeated until the requirement is met. By outputting the more optimal element parameter tolerance, the application reduces unnecessary element machining precision, saves machining cost, and can reduce the over-difference and concession acceptance rate.

Description

Technical Field

[0001] This invention relates to the field of aero-engine technology, and in particular to an air system design method for aero-engines. Background Technology

[0002] The air system of an aircraft engine refers to the system that draws air from the compressor and uses throttling elements such as flow holes, air gaps, and grates formed inside the engine to achieve functions such as disk cooling, anti-icing, active clearance control, and rim sealing.

[0003] The dimensional parameters of these throttling elements are the main output parameters of the air system design, ensuring the normal functioning of the air system, and thus affecting the rotor-stator structure design and manufacturing of components such as compressors and turbines.

[0004] Due to machining and assembly errors during production and assembly, there are discrepancies between the actual and designed dimensions of the air system's throttling elements, leading to uncertainty in the air system's design. Strict tolerance requirements can reduce this uncertainty, but they increase manufacturing complexity and cost. Conversely, if the tolerance requirements for the throttling elements are too lenient, the actual dimensions of critical throttling elements may deviate from the design expectations, failing to achieve the intended air system function and consequently affecting engine performance and operational safety.

[0005] In view of this, the inventors of this application have designed an air system design method for aircraft engines in order to overcome the above-mentioned technical problems. Summary of the Invention

[0006] The technical problem to be solved by the present invention is to overcome the defects in the design results of the air system of aero engines in the prior art, such as uncertainty, high manufacturing difficulty and increased cost, which can easily affect the performance and operational safety of the engine. The present invention provides a design method for the air system of aero engines.

[0007] The present invention solves the above-mentioned technical problems through the following technical solution:

[0008] An air system design method for an aircraft engine, characterized in that the air system design method includes the following steps:

[0009] S1. Based on the basic dimension D of the throttling element output from the preliminary design scheme of the air system, the upper and lower limits (u, l) of the preliminary machining tolerance value are given, and the tolerance data of the throttling element are set to follow a normal distribution. Thus, a probability model of the normal distribution of the dimensional parameters is constructed.

[0010] S2. Compile the sensitivity coefficient matrix of various result parameters y of the air system to the design dimension parameters b of each throttling element;

[0011] S3. Based on the sensitivity analysis results of each component in step S2, and combined with the structural engineering judgment of the processing difficulty, the given preliminary component tolerances are divided into multiple types.

[0012] S4. Based on the various types of component tolerances in step S3, carry out targeted design adjustments;

[0013] S5. Based on the tolerance range adjusted in step S4, perform probability distribution analysis on the target functional parameters to determine whether the adjusted tolerance range meets the probability requirements of the air system. If it does, output the adjusted tolerance parameters. If it does not, repeat steps S2 to S4 until the requirements are met.

[0014] According to an embodiment of the present invention, step S1 further includes: sampling based on a probability model, generating an air system calculation input file with a sample size of N, performing air system network calculation, and outputting result parameters affecting the function of the air system.

[0015] According to one embodiment of the present invention, the number of generated samples N is greater than or equal to 1000.

[0016] According to an embodiment of the present invention, the sensitivity coefficient in step S2 is calculated by the following formula:

[0017]

[0018] Where γ is the sensitivity coefficient, N is the number of samples, and b is the design size parameter.

[0019] According to one embodiment of the present invention, step S2 can obtain the probability distribution of the functional parameters by calculating the mean μ and the root mean square error σ of the result parameters of the N sample numbers.

[0020] According to one embodiment of the present invention, the functional parameter is in the range of (μ-3σ, μ+3σ).

[0021] According to an embodiment of the present invention, the types of component tolerances in step S3 include:

[0022] Category A: Low processing difficulty and high sensitivity to air system functionality;

[0023] Category B: Low processing difficulty and low sensitivity to air system functional parameters;

[0024] Category C: Highly difficult to process and highly sensitive to the gas supply system;

[0025] Category d: Highly difficult to manufacture and low sensitivity to air system functional parameters.

[0026] According to one embodiment of the present invention, step S4 further includes: making the following design adjustments based on the type of component tolerance:

[0027] Category A: Narrowing the tolerance range;

[0028] Category B: No adjustment;

[0029] Category C: Adjust the upper or lower tolerance limit at a single boundary, away from the functional failure boundary;

[0030] Class d: Increased tolerance range.

[0031] According to an embodiment of the present invention, the preliminary design scheme of the air system in step S1 includes: air system design requirements, overall parameters, overall scheme diagram, component performance parameters, component size parameters, and preliminary component tolerances.

[0032] The positive and progressive effects of this invention are as follows:

[0033] This invention relates to an air system design method for aero engines. It employs an air system component tolerance design method, which reduces unnecessary component machining precision by outputting better component parameter tolerances, thereby saving machining costs. It also identifies the component machining precision that needs to be strictly controlled, thus reducing out-of-tolerance and concession acceptance rates.

[0034] Considering the overall processing difficulty and the adjustment cycle of the scheme, based on the air system probability model within a certain tolerance range, it is possible to reduce the sensitivity of key functional parameters and reduce the uncertainty of the realization of air system functions. Attached Figure Description

[0035] The above and other features, properties and advantages of the present invention will become more apparent from the following description taken in conjunction with the accompanying drawings and embodiments, in which the same reference numerals always denote the same features, wherein:

[0036] Figure 1 This is a flowchart of the air system design method for aero engines according to the present invention.

[0037] Figure 2 This is a schematic diagram showing the sensitivity distribution of component tolerances in the air system design method for aero engines according to the present invention.

[0038] Figure 3 This is a schematic diagram of the probability distribution considering component tolerances in the air system design method for aero engines of the present invention. Detailed Implementation

[0039] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, the specific embodiments of the present invention will be described in detail below with reference to the accompanying drawings.

[0040] Embodiments of the invention will now be described in detail with reference to the accompanying drawings. Preferred embodiments of the invention will now be described in detail, examples of which are shown in the drawings. Wherever possible, the same reference numerals will be used in all the drawings to denote the same or similar parts.

[0041] Furthermore, although the terminology used in this invention is selected from commonly known and used terms, some terms mentioned in this specification may have been selected by the applicant in his or her judgment, and their detailed meanings are explained in the relevant sections of the description herein.

[0042] Furthermore, the invention should be understood not only through the actual terminology used, but also through the meaning implied by each term.

[0043] Figure 1 This is a flowchart of the air system design method for aero engines according to the present invention.

[0044] like Figure 1 As shown, this method requires the availability of air system design requirements, overall schematic diagrams, overall and component performance parameters, and a preliminary air system design. Here, the air system refers to the airflow system other than the airflow in the engine's main combustion passage.

[0045] This invention discloses a method for designing an air system for an aircraft engine, comprising the following steps:

[0046] Step S1: Based on the basic dimension D of the throttling element output from the preliminary design scheme of the air system, give the upper and lower limits (u, l) of the preliminary machining tolerance value, set the tolerance data of the throttling element to follow a normal distribution, and thus construct a probability model of the normal distribution of the dimensional parameters.

[0047] Preferably, step S1 further includes: sampling based on a probability model to generate an air system calculation input file with a sample size of N, performing air system network calculations, and outputting result parameters affecting the air system function. Here, the number of generated samples N is typically greater than or equal to 1000.

[0048] Here, the preliminary design scheme of the air system in step S1 may preferably include: air system design requirements, overall parameters, overall scheme diagram, component performance parameters, component size parameters, and preliminary component tolerances.

[0049] Step S2: Compile the sensitivity coefficient matrix of various result parameters y of the air system to the design dimension parameters b of each throttling element.

[0050] Preferably, the sensitivity coefficient in step S2 is calculated using the following formula, and the sensitivity linear graph is shown below. Figure 2 As shown.

[0051]

[0052] Where γ is the sensitivity coefficient, N is the number of samples, and b is the design size parameter.

[0053] Here, preferably, the probability distribution of the functional parameters can be obtained by calculating the mean μ and the root mean square error σ of the parameters resulting from the N sample sizes.

[0054] Preferably, the functional parameters fall within the (μ-3σ, μ+3σ) interval with a probability of 99.7%, as shown in the sample distribution diagram. Figure 3 As shown.

[0055] Sensitivity analysis here refers to an uncertainty analysis method that studies the degree of impact of changes in relevant factors on key indicators from a quantitative analysis perspective.

[0056] Step S3: Based on the sensitivity analysis results of each component in Step S2, and combined with the structural engineering judgment on the difficulty of the processing technology, the given preliminary component tolerance (which refers to the absolute value of the difference between the maximum allowable limit size and the minimum allowable limit size) is divided into multiple types.

[0057] For example, the types of component tolerances in step S3 include:

[0058] Category A: Low processing difficulty and high sensitivity to air system functionality;

[0059] Category B: Low processing difficulty and low sensitivity to air system functional parameters;

[0060] Category C: Highly difficult to process and highly sensitive to the gas supply system;

[0061] Category d: Highly difficult to manufacture and low sensitivity to air system functional parameters.

[0062] Step S4: Based on the various types of component tolerances in step S3, carry out targeted design adjustments.

[0063] For example, step S4 further includes: making the following design adjustments for the four types of component tolerances mentioned above:

[0064] Category A: Narrowing the tolerance range;

[0065] Category B: No adjustment;

[0066] Category C: Adjust the upper or lower tolerance limit at a single boundary, away from the functional failure boundary;

[0067] Class d: Increased tolerance range.

[0068] Step S5: Based on the tolerance range adjusted in step S4, perform probability distribution analysis on the target functional parameters to determine whether the adjusted tolerance range meets the probability requirements of the air system.

[0069] If satisfied, output the adjusted tolerance parameters;

[0070] If the requirements are not met, repeat steps S2 to S4 until the requirements are met.

[0071] By combining the above methods for obtaining the probabilistic model of the air system, the methods for judging the tolerances of the four types of components, and the principles for adjusting component tolerances according to certain logic, a forward design method for the tolerances of engine air system components can be obtained (e.g., Figure 1 (As shown).

[0072] Based on the steps described above, this invention establishes a dynamic tolerance design method for air systems. During the design process, a probabilistic model for the functional realization of the air system is established, thereby outputting an air system scheme with tolerance range. On the basis of functional feasibility, this method effectively reduces the difficulty of processing technology and the rate of out-of-tolerance of parts, and reduces the uncertainty of design results.

[0073] This invention relates to an air system design method for aero engines, which clarifies the following:

[0074] I. The method for obtaining a probabilistic model of an air system was clarified;

[0075] II. Clarify the principles for determining the four tolerance types of air system components;

[0076] III. Clarify the adjustment methods for the four types of tolerances in the air system;

[0077] IV. Clarify the methods for obtaining the tolerances of the output air system components.

[0078] By combining the above methods according to a certain logic, a method for positive tolerance design of air system components was obtained.

[0079] In summary, the present invention provides an air system design method for aero-engines that employs an air system component tolerance design method. By outputting better component parameter tolerances, it reduces unnecessary component machining precision, saves machining costs, identifies the component machining precision that needs to be strictly controlled, and can reduce out-of-tolerance and concession acceptance rates.

[0080] Considering the overall processing difficulty and the adjustment cycle of the scheme, based on the air system probability model within a certain tolerance range, it is possible to reduce the sensitivity of key functional parameters and reduce the uncertainty of the realization of air system functions.

[0081] For those skilled in the art, the above disclosure is merely illustrative and does not constitute a limitation of this application. Although not explicitly stated herein, those skilled in the art may make various modifications, improvements, and corrections to this application. Such modifications, improvements, and corrections are suggested in this application and therefore remain within the spirit and scope of the exemplary embodiments of this application.

[0082] Furthermore, this application uses specific terms to describe embodiments of the application. For example, "an embodiment," "one embodiment," and / or "some embodiments" refer to a particular feature, structure, or characteristic related to at least one embodiment of the application. Therefore, it should be emphasized and noted that "an embodiment," "one embodiment," or "an alternative embodiment" mentioned twice or more in different locations in this specification do not necessarily refer to the same embodiment. In addition, certain features, structures, or characteristics in one or more embodiments of the application can be appropriately combined.

[0083] Similarly, it should be noted that, in order to simplify the description of the embodiments disclosed in this application and thus aid in the understanding of one or more embodiments of the invention, the foregoing description of the embodiments of this application sometimes combines multiple features into a single embodiment, drawing, or description thereof. However, this disclosure method does not imply that the subject matter of this application requires more features than those mentioned in the claims. In fact, the embodiments have fewer features than all the features of the single embodiments disclosed above.

[0084] While specific embodiments of the present invention have been described above, those skilled in the art should understand that these are merely illustrative examples, and the scope of protection of the present invention is defined by the appended claims. Those skilled in the art can make various changes or modifications to these embodiments without departing from the principles and essence of the present invention, but all such changes and modifications fall within the scope of protection of the present invention.

Claims

1. A method for designing an air system for an aircraft engine, characterized in that, The air system design method includes the following steps: S1. Based on the basic dimension D of the throttling element output from the preliminary design scheme of the air system, the upper and lower limits (u, l) of the preliminary machining tolerance value are given, and the tolerance data of the throttling element are set to follow a normal distribution. Thus, a probability model of the normal distribution of the dimensional parameters is constructed. S2. Compile the sensitivity coefficient matrix of various result parameters y of the air system to the design dimension parameters b of each throttling element; S3. Based on the sensitivity analysis results of each component in step S2, and combined with the structural engineering judgment of the processing difficulty, the given preliminary component tolerances are divided into multiple types. S4. Based on the various types of component tolerances in step S3, carry out targeted design adjustments; S5. Based on the tolerance range adjusted in step S4, perform probability distribution analysis on the target functional parameters to determine whether the adjusted tolerance range meets the probability requirements of the air system. If satisfied, output the adjusted tolerance parameters; If the requirements are not met, repeat steps S2 to S4 until the requirements are met.

2. The air system design method for an aero-engine as described in claim 1, characterized in that, Step S1 further includes: sampling based on a probability model, generating an air system calculation input file with N samples, performing air system network calculations, and outputting result parameters that affect the function of the air system.

3. The air system design method for an aero-engine as described in claim 2, characterized in that, The number of samples N generated is greater than or equal to 1000.

4. The air system design method for an aero-engine as described in claim 1, characterized in that, The sensitivity coefficient in step S2 is calculated using the following formula: Where γ is the sensitivity coefficient, N is the number of samples, and b is the design size parameter.

5. The air system design method for an aero-engine as described in claim 4, characterized in that, Step S2 obtains the probability distribution of the functional parameters by calculating the mean μ and standard deviation σ of the result parameters for N sample numbers.

6. The air system design method for an aero-engine as described in claim 5, characterized in that, The functional parameters are in the range of (μ-3σ, μ+3σ).

7. The air system design method for an aero-engine as described in claim 1, characterized in that, The types of component tolerances in step S3 include: Category A: Low processing difficulty and high sensitivity to air system functionality; Category B: Low processing difficulty and low sensitivity to air system functional parameters; Category C: Highly difficult to process and highly sensitive to the gas supply system; Category d: Highly difficult to manufacture and low sensitivity to air system functional parameters.

8. The air system design method for an aero-engine as described in claim 7, characterized in that, Step S4 also includes: making the following design adjustments based on the type of component tolerance: Category A: Narrowing the tolerance range; Category B: No adjustment; Category C: Adjust the upper or lower tolerance limit at a single boundary, away from the functional failure boundary; Class d: Increased tolerance range.

9. The air system design method for an aero-engine as described in claim 1, characterized in that, The preliminary design scheme for the air system in step S1 includes: Air system design requirements, overall parameters, overall schematic diagram, component performance parameters, component size parameters, and preliminary component tolerances.

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