Method for calculating heat transfer coupling temperature of compressor disc

Abstract

The application aims to provide a compressor disc flow-heat coupling temperature calculation method, which comprises the following steps: obtaining a fluid flow analysis result in a compressor disc cavity; dividing the compressor disc cavity into a first cavity and a second cavity according to the analysis result; simplifying the cavity temperature of the first cavity into one cavity temperature node, and obtaining the temperature of the cavity temperature node and the wall surface node of the first cavity; simplifying the cavity temperature of the second cavity into a heat flow line which exchanges heat with the wall surface of the compressor disc cavity, and constructing a heat balance equation of the heat flow line, and obtaining the temperature of the wall surface node of the second cavity according to the heat balance equation. The method can improve the heat analysis precision of the compressor disc.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of gas turbine engines, in particular to a method for calculating the flow-thermal coupling temperature of a compressor disc. BACKGROUND

[0002] With the development of aero-engine technology, the working environment of the compressor is becoming increasingly harsh, and accurate prediction of its temperature distribution is very important. Accurate part thermal analysis can not only provide reliable part temperature data for strength and life design, but also be an important basis for the life determination of the airworthy engine life-limited parts.

[0003] The compressor rotating disc cavity is the main part of the cooling air flow path in the aero-engine, and has typical aerodynamic and heat transfer coupling characteristics. The traditional compressor disc thermal analysis is based on the third type of heat transfer boundary to solve the heat conduction differential equation to obtain the compressor rotor temperature field. The heat transfer temperature is generally given by experience, and the fluid gas temperature and solid temperature of the metal surface are usually decoupled. However, due to the significant rotational flow in the compressor rotor disc cavity, the rotor disc surface experiences relative total temperature, and the heat transfer between the fluid and the solid will affect the heat transfer temperature of the rotor disc surface. Therefore, the decoupled solution between the air and the rotating disc may bring a large calculation error to the compressor rotor temperature calculation. In order to solve this problem, the current main method is to use the flow-thermal coupling calculation method of the CFD software to couple the heat transfer boundary on the fluid-solid interface and the solid temperature, but such method also has some problems, such as a large number of grids, a long time for pre-processing and calculation, and a high total calculation cost, which is not suitable for rapid evaluation of multiple schemes in engineering.

[0004] There is an urgent need to provide a compressor disc flow-thermal coupling temperature calculation method to improve the accuracy of compressor disc thermal analysis. SUMMARY

[0005] The purpose of the present application is to provide a compressor disc flow-thermal coupling temperature calculation method that can improve the accuracy of compressor disc thermal analysis.

[0006] To achieve the aforementioned purpose, the compressor disc flow-thermal coupling temperature calculation method comprises the following steps:

[0007] Obtaining the fluid flow analysis result in the compressor disc cavity;

[0008] According to the analysis result, the compressor disc cavity is divided into a first cavity and a second cavity, the first cavity is located radially outside the second cavity, and the fluid flow state in the first cavity is different from that in the second cavity;

[0009] The temperature inside the first cavity is simplified to a cavity temperature node. Considering the heat exchange between the cavity temperature node and the compressor disk cavity wall, the temperatures of the cavity temperature node and the first cavity wall node are obtained.

[0010] The internal temperature of the second cavity is simplified to a heat flow line that exchanges heat with the wall of the compressor disk, and a heat balance equation for the heat flow line is constructed. The temperature of the nodes on the wall of the second cavity is obtained based on the heat balance equation.

[0011] In one or more embodiments, fluid flow in the first cavity is dominated by centrifugal force, and fluid flow in the second cavity is dominated by inertial force.

[0012] In one or more embodiments, considering the heat exchange between the cavity temperature node and the compressor disk cavity wall, a set of heat balance equations is obtained within the first cavity. The temperatures of the cavity temperature node and the first cavity wall node are obtained by solving the set of heat balance equations simultaneously.

[0013] In one or more embodiments, the heat balance equations include the following formulas (1) to (6):

[0014] ∑h i A i (T wi -T f )+H in -H out =0 (1);

[0015]

[0016] T out =T f (5);

[0017]

[0018] Among them, T wi It is the temperature of the first cavity wall node, T f It is the temperature of the first cavity temperature node, H. in It is the enthalpy of the axial flow entering the first cavity of the disk core, H out It is the enthalpy of the axial flow that leaves the first cavity and merges into the center of the disk. It is the flow rate entering the first cavity. It is the isobaric specific heat capacity of the gas entering the first chamber, T in It is the temperature of the gas entering the first chamber. It is the flow rate leaving the first cavity. It is the isobaric specific heat capacity of the gas leaving the first chamber, T out It is the temperature of the gas leaving the first chamber, h iIt is the local heat transfer coefficient, A i It is the local heat exchange area, T ni λ is the internal temperature of the first cavity wall, q is the thermal conductivity. λ It is the thermal flux density parallel to the wall of the first cavity.

[0019] In one or more embodiments, the heat balance equation of the heat flow line is as follows (7):

[0020]

[0021] Among them, T w It is the temperature of the second cavity wall, T fn Where is the local airflow temperature, h is the local heat transfer coefficient, and A is the local heat transfer area. It is the airflow mass flow rate, C p It is the specific heat capacity of airflow at constant pressure.

[0022] In one or more embodiments, the temperature of the second cavity wall node is obtained according to the heat balance equation and the heat balance equation of the metal surface node, wherein the heat balance equation of the metal surface node is as follows (8):

[0023]

[0024] Among them, T ni It is the internal temperature of the second cavity wall, T wi λ is the temperature at the node of the second cavity wall, λ is the thermal conductivity, and q is the temperature at the node of the second cavity wall. λ It is the thermal flux density parallel to the wall of the first cavity.

[0025] In one or more embodiments, computational fluid dynamics simulation software is used to analyze the fluid flow within the compressor disk cavity to obtain the analysis results of the fluid flow within the compressor disk cavity.

[0026] On the other hand, according to some embodiments of this application, a readable storage medium is provided on which computer instructions are stored, which, when executed by a processor, implement the steps of the compressor disk flow thermal coupling temperature calculation method as described above.

[0027] The beneficial effects of this invention are as follows:

[0028] This method utilizes CFD flow analysis results to obtain the flow structure within the axially penetrating compressor disk cavity. Then, based on the flow characteristics within the cavity, it is divided into several regions. For these regions, the model is simplified using the energy conservation equation, reducing the fluid to a one-dimensional flow. Thermal equilibrium is considered between the one-dimensional fluid and the surface of the two-dimensional solid finite element thermal analysis model. A compressor disk thermal analysis model based on thermal cavities and thermal streamlines is established to simulate energy exchange within the compressor disk cavity. The flow-thermal coupling effect is considered in the solid finite element calculation, thereby improving the accuracy of compressor disk temperature calculation. This method accelerates the solution speed while considering flow-thermal coupling, reflecting physical reality as closely as possible, thus improving the accuracy of compressor disk thermal analysis in engineering and meeting the needs of rapid temperature assessment in model applications.

[0029] The above description is only an overview of the technical solution of this application. In order to better understand the technical means of this application and to implement it in accordance with the contents of the specification, and to make the above and other objects, features and advantages of this application more obvious and understandable, the following are specific embodiments of this application. Attached Figure Description

[0030] Various other advantages and benefits will become apparent to those skilled in the art upon reading the detailed description of the preferred embodiments below. The accompanying drawings are for illustrative purposes only and are not intended to limit the scope of this application. Furthermore, the same reference numerals denote the same parts throughout the drawings. In the drawings:

[0031] Figure 1 A schematic diagram of the CFD flow analysis results for the compressor disk cavity is shown;

[0032] Figure 2 A schematic diagram of the partitioning of the compressor disk cavity at different locations is shown based on the compressor disk flow-thermal coupling temperature calculation method described herein;

[0033] Figure 3 A schematic diagram of the thermal balance of the thermal cavity inside the compressor disc is shown;

[0034] Figure 4 The heat flow line balance diagram is shown according to the method for calculating the thermal coupling temperature of the compressor disk flow.

[0035] Figure 5 A schematic diagram of the thermal flow lines and thermal cavity arrangement of a typical compressor disk finite element model is shown. Detailed Implementation

[0036] The embodiments of the technical solution of this application will now be described in detail with reference to the accompanying drawings. These embodiments are only used to more clearly illustrate the technical solution of this application and are therefore merely examples, and should not be used to limit the scope of protection of this application.

[0037] Unless otherwise defined, all technical and scientific terms used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this application pertains; the terminology used herein is for the purpose of describing particular embodiments only and is not intended to limit the application; the terms “comprising” and “having”, and any variations thereof, in the specification, claims, and foregoing description of the drawings are intended to cover non-exclusive inclusion.

[0038] Traditional compressor disk temperature calculations employ fluid-thermal decoupling, which fails to reflect physical reality and results in low temperature accuracy. While CFD calculations can consider fluid-thermal coupling and reflect more detailed flow and heat transfer, they are time-consuming and require significant preprocessing, making them unsuitable for the rapid temperature assessment needs of engineering applications. Therefore, finding a solution that both accelerates the calculation process and accurately reflects physical reality while considering fluid-thermal coupling is a pressing issue in current compressor disk thermal analysis.

[0039] According to some embodiments of this application, a method for calculating the thermal coupling temperature of a compressor disk flow is provided, which includes the following steps:

[0040] To obtain the fluid flow analysis results within the compressor disk cavity, specifically, computational fluid dynamics (CFD) simulation software is used to analyze the fluid flow within the compressor disk cavity to obtain the fluid flow analysis results within the compressor disk cavity.

[0041] Based on the analysis results, the compressor disk cavity is divided into a first cavity 1 and a second cavity 2 along the radial direction a of the compressor disk cavity, as follows: Figure 1 A schematic diagram of the CFD flow analysis results for the compressor disk cavity is shown. Figure 2 The diagram shows the partitioning of the compressor disk cavity at different locations. The first cavity 1 is located radially outside the second cavity 2. The fluid flow state in the first cavity 1 is different from that in the second cavity 2.

[0042] In a specific embodiment, such as Figure 1As shown, the flow structures within each level of the compressor disk are similar. In the first cavity 1 at the high radius, a rigid vortex with a velocity close to the rotational speed of the disk wall exists, primarily driven by centrifugal force. In the second cavity 2 at the low radius, after the axial flow of the airflow reaches the disk inlet, a portion intrudes into the disk. This intruding airflow exchanges heat with the airflow within the disk and the compressor disk wall, eventually leaving the disk and merging back into the main flow, flowing downstream into the next disk cavity, and so on. Therefore, dividing the compressor disk into the first cavity 1 and the second cavity 2, the fluid flow in the first cavity 1 is dominated by centrifugal force, while the fluid flow in the second cavity 2 is dominated by inertial force. Since the heat transfer on the disk wall is mainly affected by the flow state of the surrounding airflow, the axially flowing disk can be roughly divided into upper and lower regions in the finite element thermal analysis model, and thermal models can be established separately for each region, thereby improving computational efficiency.

[0043] Subsequently, the internal temperature of the first cavity is simplified to a single cavity temperature node, such as... Figure 2 As shown, a portion of the airflow from the left side of the disk cavity inlet enters the disk cavity due to centrifugal force. Within the second cavity 2, the airflow exchanges heat with the compressor disk wall while flowing into the high-radius first cavity 1; the remaining airflow continues to flow backward along the axial direction b. This intruding airflow entering the first cavity 1 brings in a portion of enthalpy. Furthermore, due to mass conservation, after heat exchange with the airflow within the rigid vortex of the first cavity 1, this portion of airflow carries away a portion of enthalpy, leaving the first cavity 1 and entering the second cavity 2. Finally, it merges with the axial flow in the disk center region and then flows axially to the next stage of the disk cavity. Since the airflow within the first cavity 1 is a rigid vortex with a relatively small heat transfer coefficient and a relatively uniform heat transfer temperature, in the finite element temperature heat transfer boundary treatment, it can be assumed that the heat transfer temperature within the first cavity 1 is uniform. The cavity temperature is simplified to a single node, and the temperature of this node is used to express the cavity temperature of the first cavity 1; this node is the cavity temperature node. Considering the heat exchange between the cavity temperature node and the compressor disk cavity wall in the first cavity 1, the temperatures of the cavity temperature node and the compressor disk cavity wall node in the first cavity 1 can be obtained. The wall node is the location of the point on the compressor wall where the temperature needs to be obtained.

[0044] Subsequently, the internal temperature of the second cavity 2 is simplified to a heat flow line 3 that exchanges heat with the wall of the compressor disc, such as... Figure 4 As shown, the airflow near the center of the second cavity 2 will experience temperature changes along the path. It cannot be simplified to a point like the hot cavity, but is simplified to a line that exchanges heat with the wall, namely the heat flow line 3. By constructing the heat balance equation of the heat flow line, the temperature of the compressor wall node of the second cavity 2 can be obtained according to the heat balance equation.

[0045] This method utilizes CFD flow analysis results to obtain the flow structure within the axially penetrating compressor disk cavity. Then, based on the flow characteristics within the cavity, it is divided into several regions. For these regions, the model is simplified using the energy conservation equation, reducing the fluid to a one-dimensional flow. Thermal equilibrium is considered between the one-dimensional fluid and the surface of the two-dimensional solid finite element thermal analysis model. A compressor disk thermal analysis model based on thermal cavities and thermal streamlines is established to simulate energy exchange within the compressor disk cavity. The flow-thermal coupling effect is considered in the solid finite element calculation, thereby improving the accuracy of compressor disk temperature calculation. This method accelerates the solution speed while considering flow-thermal coupling, reflecting physical reality as closely as possible, thus improving the accuracy of compressor disk thermal analysis in engineering and meeting the needs of rapid temperature assessment in model applications.

[0046] In the description of the embodiments of this application, the technical terms "first" and "second," such as "first cavity" and "second cavity," are used only to distinguish different objects and should not be construed as indicating or implying relative importance or implicitly specifying the number, specific order, or primary and secondary relationship of the indicated technical features. In the description of the embodiments of this application, "multiple" means two or more, unless otherwise explicitly defined.

[0047] In this document, the term "embodiment" means that a particular feature, structure, or characteristic described in connection with an embodiment may be included in at least one embodiment of this application. The appearance of this phrase in various places throughout the specification does not necessarily refer to the same embodiment, nor is it a separate or alternative embodiment mutually exclusive with other embodiments. It will be explicitly and implicitly understood by those skilled in the art that the embodiments described herein can be combined with other embodiments.

[0048] In some embodiments of the compressor disk flow thermal coupling temperature calculation method, the temperature of the cavity temperature node and the temperature of the first cavity wall node of the first cavity 1 are obtained by considering the heat exchange between the cavity temperature node and the compressor disk cavity wall, and the heat balance equations in the first cavity are obtained by solving the heat balance equations simultaneously.

[0049] Specifically, the heat balance equations include the following formulas (1) to (6):

[0050] ∑h i A i (T wi -T f )+H in -H out =0 (1);

[0051]

[0052] According to the law of conservation of mass:

[0053] Based on the flow characteristics of the compressor disk cavity, the temperature of the gas exiting the hot cavity should be approximately equal to the temperature of the gas within the hot cavity itself. Therefore: T out =T f (5);

[0054] Combination Figure 3 As shown, for temperature node i on the metal surface of the compressor disk cavity, the heat balance equation can be listed as follows:

[0055] Among them, T wi It is the temperature of the first cavity wall node, T f It is the temperature of the first cavity temperature node, H. in It is the enthalpy of the axial flow entering the first cavity of the disk core, H out It is the enthalpy of the axial flow that leaves the first cavity and merges into the center of the disk. It is the flow rate entering the first cavity. It is the isobaric specific heat capacity of the gas entering the first chamber, T in It is the temperature of the gas entering the first chamber. It is the flow rate leaving the first cavity. It is the isobaric specific heat capacity of the gas leaving the first chamber, T out It is the temperature of the gas leaving the first chamber, h i It is the local heat transfer coefficient, A i It is the local heat exchange area, T ni λ is the internal temperature of the first cavity wall, q is the thermal conductivity. λ It is the thermal flux density parallel to the wall of the first cavity. By solving (1)-(6) simultaneously, the temperature of the nodes of the first cavity 1 and the temperature of the nodes of the compressor disk wall of the first cavity 1 can be obtained.

[0056] Combination Figure 4 As shown, in some embodiments of the compressor disk flow thermal coupling temperature calculation method, the heat balance equation of the heat flow line is as follows (7):

[0057]

[0058] Among them, T w It is the temperature of the second cavity wall, T fn Where is the local airflow temperature, h is the local heat transfer coefficient, and A is the local heat transfer area. It is the airflow mass flow rate, C p It is the specific heat capacity of airflow at constant pressure.

[0059] In some embodiments of the compressor disk flow thermal coupling temperature calculation method, the temperature of the second cavity wall node is obtained according to the thermal balance equation and the thermal balance equation of the metal surface node. The thermal balance equation of the metal surface node is as follows (8), which is the aforementioned thermal balance equation of the compressor disk cavity metal surface temperature node i:

[0060]

[0061] Among them, T ni It is the internal temperature of the second cavity wall, T wi λ is the temperature at the nodal point of the second cavity wall, λ is the thermal conductivity, and q is the temperature at the nodal point of the second cavity wall. λ It is the thermal flux density parallel to the wall of the first cavity.

[0062] Figure 5 The arrangement of the heat flow lines 101 and hot cavities 100 in a typical compressor disk finite element model is presented. When solving for the temperature field, the solid temperature field and the one-dimensional fluid temperature field can be obtained simultaneously by combining the solid heat conduction equation and the fluid one-dimensional energy conservation equation. This method combines the advantages of CFD and traditional finite element thermal analysis methods, improving the accuracy of compressor disk temperature calculation while maintaining computational efficiency, thus better supporting the design of various compressor models.

[0063] The computer-readable storage medium provided in this disclosure stores computer instructions thereon. When executed by a processor, these computer instructions can implement the compressor disk flow-thermal coupling temperature calculation method provided in any of the above embodiments, thereby improving the accuracy of compressor disk thermal analysis.

[0064] The steps of the methods or algorithms described in conjunction with the embodiments disclosed herein may be embodied directly in hardware, in a software module executed by a processor, or in a combination of both. The software module may reside in RAM memory, flash memory, ROM memory, EPROM memory, EEPROM memory, registers, hard disk, removable disk, CD-ROM, or any other form of storage medium known in the art. An exemplary storage medium is coupled to a processor such that the processor can read and write information to / from the storage medium. In an alternative, the storage medium may be integrated into the processor. The processor and storage medium may reside in an ASIC. The ASIC may reside in a user terminal. In an alternative, the processor and storage medium may reside as discrete components in the user terminal.

[0065] In one or more exemplary embodiments, the described functionality may be implemented in hardware, software, firmware, or any combination thereof. If implemented in software as a computer program product, the functionality may be stored or transmitted as one or more instructions or code on or through a computer-readable medium. A computer-readable medium includes both computer storage media and communication media, encompassing any medium that facilitates the transfer of a computer program from one location to another. A storage medium may be any available medium accessible to a computer. By way of example and not limitation, such a computer-readable medium may include RAM, ROM, EEPROM, CD-ROM or other optical disc storage, disk storage or other magnetic storage devices, or any other medium that can be used to carry or store desired program code in the form of instructions or data structures and is accessible to a computer. Any connection is also legitimately referred to as a computer-readable medium. For example, if the software is transmitted from a website, server, or other remote source using coaxial cable, fiber optic cable, twisted pair, digital subscriber line (DSL), or wireless technologies such as infrared, radio, and microwave, then the coaxial cable, fiber optic cable, twisted pair, DSL, or wireless technologies such as infrared, radio, and microwave are included in the definition of a medium. As used in this article, disk and disc include compact discs (CDs), laser discs, optical discs, digital multi-purpose discs (DVDs), floppy disks, and Blu-ray discs. Disks typically reproduce data magnetically, while discs reproduce data optically using lasers. Combinations of these should also be included within the scope of computer-readable media.

[0066] It should be understood that the use of "along" in the text means that there is at least a component in that direction, preferably, the angle with that direction is within 10°, more preferably, the angle is within 5°.

[0067] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of this application, and not to limit them. Although this application has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some or all of the technical features therein. These modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of this application, and they should all be covered within the scope of the claims and specification of this application. In particular, as long as there is no structural conflict, the various technical features mentioned in the embodiments can be combined in any way. This application is not limited to the specific embodiments disclosed herein, but includes all technical solutions falling within the scope of the claims.

Claims

1. A method for calculating the thermal coupling temperature of a compressor disk flow, characterized in that, Includes the following steps: Obtain the fluid flow analysis results within the compressor disk cavity; Based on the analysis results, the compressor disk cavity is divided into a first cavity and a second cavity. The first cavity is located radially outside the second cavity, and the fluid flow state in the first cavity is different from that in the second cavity. The temperature inside the first cavity is simplified to a cavity temperature node. Considering the heat exchange between the cavity temperature node and the compressor disk cavity wall, the temperatures of the cavity temperature node and the first cavity wall node are obtained. The temperature inside the second cavity is simplified to a heat flow line that exchanges heat with the wall of the compressor disk, and a heat balance equation for the heat flow line is constructed. The temperature of the nodes on the wall of the second cavity is obtained based on the heat balance equation. Considering the heat exchange between the cavity temperature node and the compressor disk cavity wall, a set of heat balance equations is obtained in the first cavity. The temperatures of the cavity temperature node and the first cavity wall node are obtained by solving the set of heat balance equations simultaneously. The heat balance equations include the following formulas (1) to (6): （1）； （2）； （3）； （4）； （5）； （6）； in, The temperature of the first cavity wall node, It is the temperature of the first cavity temperature node. It is the enthalpy of the axial flow entering the first cavity of the disk. It is the enthalpy of the axial flow that leaves the first cavity and merges into the center of the disk. It is the flow rate entering the first cavity. It is the isobaric specific heat capacity of the gas entering the first chamber. It is the temperature of the gas entering the first chamber. It is the flow rate leaving the first cavity. It is the isobaric specific heat capacity of the gas leaving the first chamber. It is the temperature of the gas leaving the first chamber. It is the local heat transfer coefficient. It is the local heat exchange area. It is the internal temperature of the first cavity wall. It is the thermal conductivity. It is the thermal flux density parallel to the wall of the first cavity.

2. The method for calculating the compressor disk flow thermal coupling temperature as described in claim 1, characterized in that, The fluid flow in the first cavity is dominated by centrifugal force, while the fluid flow in the second cavity is dominated by inertial force.

3. The method for calculating the compressor disk flow thermal coupling temperature as described in claim 1, characterized in that, The heat balance equation for the heat flow line is as follows (7): （7）； in, It is the temperature of the second cavity wall. It is the local air temperature. It is the local heat transfer coefficient. It is the local heat exchange area. It is the mass flow rate of the airflow. It is the specific heat capacity of airflow at constant pressure.

4. The method for calculating the compressor disk flow thermal coupling temperature as described in claim 3, characterized in that, The temperature of the second cavity wall node is obtained according to the heat balance equation and the heat balance equation of the metal surface node. The heat balance equation of the metal surface node is as follows (8): （8）； in, It is the internal temperature of the second cavity wall. It is the temperature of the second cavity wall node. It is the thermal conductivity. It is the thermal flux density parallel to the wall of the first cavity.

5. The method for calculating the compressor disk flow thermal coupling temperature as described in claim 1, characterized in that, Computational fluid dynamics simulation software was used to analyze the fluid flow inside the compressor disc cavity to obtain the analysis results.

6. A readable storage medium, characterized in that, It stores computer instructions that, when executed by a processor, implement the steps of the compressor disk flow thermal coupling temperature calculation method as described in any one of claims 1 to 5.

Images