JP2002073702A - Structure analysis method for rotary machine - Google Patents

Abstract

PROBLEM TO BE SOLVED: To provide a structure analysis method for a rotary machine, capable of analyzing by exactly transmitting bending force generated in a blade to a disc. SOLUTION: A blade shape, constituted of a meridian planar shape of an impeller and a point group, is defined by a solid model by using a structure analysis program for preparing not a plate element but the meridian planar shape and the blade shape, the meridian plane shape and the blade shape of the solid model are automatically divided into a plurality of meshes, by using an automatic preparing program for a solid FEM data exclusive for the impeller, the meshes are analyzed structurally, and the result is displayed in images.

Description

DETAILED DESCRIPTION OF THE INVENTION

[0001]

The present invention relates to a method for analyzing the structure of a rotating machine.

[0002]

2. Description of the Related Art A rotating machine such as a supercharger (turbocharger) or a turbocompressor is a fluid machine having a complicated three-dimensional shape including many free-form surfaces, includes many mechanical elements, and has a high temperature. It is exposed to the harsh environment of high-speed rotation at a speed. Therefore, CAE (Computer Aided E)
It has become essential to incorporate ngineering.

[0003] Conventionally, structural analysis of structural parts has been performed mainly on vehicle superchargers, marine superchargers, screw compressors, centrifugal compressors and the like. In addition, stress analysis due to external force and pressure, thermal stress analysis due to heat, vibration analysis due to eigenvalues for compressor housing, turbine impeller, rotor as rotating parts, housing as a stationary part, heat shield plate, etc. And so on.

[0004]

(1) For example, in the design and development process of a rotating machine such as a turbocharger,
Since the structural analysis was performed after the two-dimensional drawing was completed, it sometimes took several months for the structural analysis results to be obtained. For this reason, since it is not possible to wait until the analysis result is obtained, the prototype and the test are performed at the same time, and the analysis result is completed when the product is completed. At this point, if the problem was solved, the designer had to return to the design and repeat the long process. A first object of the present invention is to provide a method for analyzing the structure of a rotating machine that solves the above-mentioned problems and reduces the need for returning to the design process by evaluating prototypes and tests.

(2) The compressor impeller and the turbine impeller are important parts that rotate at high speed. Conventionally, such impeller analysis simulates the blade part as a plate element,
The data volume was reduced and data creation was simplified. Also, the disk part was analyzed as a solid element. Further, when the entire impeller is analyzed, the amount of data becomes large. Therefore, one pitch for one blade is extracted and calculated. However, this analysis method can analyze the strength of the blade, but cannot accurately analyze the disk portion. That is, when the blade is a plate element, the connection between the blade and the disk is analyzed as a bar (bar) element, so that the bending force generated on the blade is not transmitted to the disk. A second object of the present invention is to solve such a problem and to provide a method of analyzing the structure of a rotating machine capable of accurately transmitting a bending force generated on a blade to a disk for analysis.

(3) Conventional structural analysis of an impeller or the like has been carried out by repetitive work of creating a shape model, performing an analysis, changing the shape based on the evaluation result, and performing calculations again. That is, in the conventional structural analysis method, although the final evaluation is performed based on the stress value and the displacement, the optimum shape for obtaining the optimum value is repeatedly performed based on experience and intuition. Therefore, a skilled developer is indispensable, and it takes a long time to obtain an optimum shape. A third object of the present invention is to provide a method of analyzing the structure of a rotating machine capable of solving such a problem and determining an optimum shape in a short time without relying on experience or intuition.

[0007]

According to the first aspect of the present invention, a design is performed in three dimensions, the design data is directly used for structural analysis using a computer, the analysis result is evaluated and fed back to the design. And a method for analyzing the structure of a rotating machine.

According to the method of the present invention, structural analysis using a computer, that is, CAE (Computer A)
If the evaluation result of “idled Engineering” is good, it is possible to directly proceed to trial production and testing. Therefore, this method has already provided analysis results that have been sufficiently evaluated at the stage of trial production and testing, and therefore, the number of times of returning to the design process by evaluation in trial production and testing is reduced. In other words, CAE is not used only for analysis after trial production and test as in the past, but is incorporated into the design development process and utilized at the initial stage of design development, thereby returning to the design process by evaluation of prototype and test. Can be reduced.

According to the second aspect of the present invention, the meridian plane shape of the impeller and the blade shape composed of the point group are defined by a solid model using a structural analysis program for creating the meridional plane shape and the blade shape instead of the plate element. , Solid FE for impeller
A method for automatically dividing a meridional plane shape and a blade shape of the solid model into a plurality of meshes by using an M data automatic creation program, analyzing the structure and displaying the result as an image, Is provided.

According to the method of the present invention, in addition to the meridional plane coordinates of the blades from the fluid analysis data, the blade coordinates are also extracted at the same time. Elements can be created. Further, the number of elements can be changed, and the roughness of the mesh can also be changed. Further, since the data is all solid elements, the problem of force transmission can be solved. Therefore, (1) the force of the blade portion and the disk portion can be transmitted correctly,
(2) The blade data creation time is shortened, and (3) the program operates even if the number of elements is changed, so that the roughness of the elements can be changed freely.

According to a third aspect of the present invention, there is provided a method for analyzing the structure of a rotating machine, comprising inputting final constraints such as a stress value and a displacement, and obtaining an optimum shape satisfying the conditions. You. According to the method of the present invention, the optimum shape that satisfies the stress value, the displacement, and the like can be obtained without the repetition of the optimum shape of the blade, the optimum shape of the disk, and the like.

[0012]

DESCRIPTION OF THE PREFERRED EMBODIMENTS Preferred embodiments of the present invention will be described below with reference to the drawings. FIG. 1 shows a method for analyzing the structure of a rotating machine according to the present invention, that is, CAE (Computer).
It is a figure which shows the positioning of Aided Engineering typically. Conventionally, as shown in FIG. 1A, structural analysis was performed after a two-dimensional drawing was completed, so that it sometimes took several months to obtain a result of the structural analysis. For this reason, since it is not possible to wait until the analysis result is obtained, the prototype and the test are performed at the same time, and the analysis result is completed when the product is completed. At this point, if the problem was solved, the designer had to return to the design and repeat the long process.

On the other hand, as shown in FIG.
In the method of analyzing the structure of a rotating machine according to the present invention, the design is performed in three dimensions, the design data is used as it is for CAE (structural analysis using a computer), and the analysis result is evaluated and fed back to the design. Then, if the evaluation result is good, proceed to trial production and testing. By this method, the analysis result that has already been sufficiently evaluated at the stage of the trial manufacture and test has been obtained, so that the evaluation in the trial manufacture and test reduces the need to return to the design process. In other words, CAE is not used only for analysis after trial production and test as in the past, but is incorporated into the design development process and utilized at the initial stage of design development, thereby returning to the design process by evaluation of prototype and test. Can be reduced.

Hereinafter, an example of analysis in a rotating machine will be described. FIG. 2 is a cross-sectional view of a turbocharger to be subjected to structural analysis. This figure shows the main analysis items of the rotating machine, that is, the supercharger. Parts for structural analysis are compressor impeller,
A turbine impeller, a compressor housing, a turbine housing, a bearing housing, and the like.

First, the compressor impeller will be described. A compressor is a component that rotates, for example, 240,000 revolutions per minute, and is one of the most important components in a supercharger. Conventionally, such an impeller analysis simulates a blade part as a plate element to reduce the amount of data and facilitate data creation. Also, the disk part was analyzed as a solid element. Further, when the entire impeller is analyzed, the amount of data becomes large. Therefore, one pitch for one blade is extracted and calculated.

FIG. 3A shows a conventional impeller analysis procedure using meridional plane data for fluid analysis. FIG. 4 shows a result of centrifugal stress analysis of a blade as a conventional plate element. FIG. 5 shows the result of centrifugal stress analysis of a conventional compressor impeller including a disk portion having blades as plate elements. FIG. 6 shows a centrifugal stress analysis result obtained by analyzing a conventional blade using solid elements. However, the conventional analysis method can analyze the strength of the blade, but cannot accurately analyze the disk portion. That is, when the blade is a plate element, the connection between the blade and the disk is analyzed as a bar (bar) element, so that the bending force generated on the blade is not transmitted to the disk. In addition, a large amount of time was required because the data for solidifying the blades was manually created.

FIG. 3B shows an impeller analysis procedure according to the present invention. In this structural analysis method, a structural analysis code I-DEAS for creating a meridional plane shape and a blade shape instead of a plate element is provided.
In order to shorten the time required for mesh generation, a new automatic FEM data creation program (IMPFEM) dedicated to impellers was newly developed and introduced.

That is, using a structural analysis program that creates a meridional plane shape and a blade shape instead of a plate element, the meridian shape of the impeller and the blade shape composed of point groups are defined by a solid model, and the solid FEM data for the impeller is automatically defined. The meridional plane shape and the blade shape of the solid model are automatically divided into a plurality of meshes using a creation program, and the mesh is structurally analyzed, and the result is displayed as an image.

The automatic solid FEM data creation program dedicated to the impeller not only extracts the meridional plane coordinates of the blades from the fluid analysis data, but also extracts the blade coordinates at the same time, so that a solid element can be generated in a short time. . The number of elements can be changed, and the roughness of the mesh can be changed. Further, since the data is all solid elements, the problem of force transmission can be solved. Therefore, (1) the force between the blade portion and the disk portion can be transmitted correctly, and (2) the time for creating blade data is reduced,
(3) Since the program operates even if the number of elements is changed,
The roughness of the element can be changed freely.

FIG. 7 shows an example of a centrifugal stress analysis in which the entire compressor impeller with all the blades is analyzed using solid elements. As shown in this figure, the analysis method of the present invention described above can easily analyze a point group impeller having a three-dimensional free-form surface shape defined by a point group.

Next, the turbine impeller will be described.
The turbine impeller also rotates at high speed and is exposed to a gas exceeding 900 ° C.

FIG. 8 shows the result of centrifugal stress analysis obtained by analyzing a conventional blade using plate elements. FIG. 9 shows the result of centrifugal stress analysis by the method of the present invention in which the blade is analyzed as a solid element. FIG. 10 shows first to third modes in the eigenvalue analysis of the blade. FIG. 11 shows the structural analysis software and its use classification.

FIG. 12 (A) is a conventional impeller shape determining process diagram, and FIG. 12 (B) is a shape determining process diagram according to the present invention. As shown in FIG. 12A, the conventional structural analysis of an impeller or the like is performed by repeating a work of creating a shape model, performing an analysis, changing the shape based on the evaluation result, and performing a calculation again. That is, in the conventional structural analysis method, although the final evaluation is performed based on the stress value and the displacement, the optimum shape for obtaining the optimum value is repeatedly performed based on experience and intuition. Therefore, a skilled developer is indispensable, and it takes a long time to obtain an optimum shape.

On the other hand, the structure analysis method of the present invention shown in FIG. 12B introduces a process of obtaining an optimum shape satisfying the stress value, displacement, and the like under constraints. For example, as for the impeller, the optimum shape of the blade, the optimum shape of the disk, and the like are obtained first without repetitive operations.
Further, the present invention is similarly applied to a coupled problem between a thermal fluid analysis and a structural analysis.

It should be noted that the present invention is not limited to the above-described embodiment, but can be variously modified without departing from the gist of the present invention.

[0026]

As described above, according to the method for analyzing the structure of a rotating machine of the present invention, (1) the return to the design process can be reduced by the evaluation of the prototype and the test, and (2) the bending force generated on the blade. Is accurately transmitted to the disk for analysis, and (3) an optimum shape can be determined in a short time without relying on experience or intuition.

[Brief description of the drawings]

FIG. 1 is a diagram schematically showing the positioning of a method for analyzing the structure of a rotating machine according to the present invention.

FIG. 2 is a cross-sectional view of a turbocharger to be subjected to structural analysis.

FIG. 3 is a diagram showing an impeller analysis procedure.

FIG. 4 is a result of centrifugal stress analysis of a blade and a disk as conventional plate elements.

FIG. 5 is a result of centrifugal stress analysis of a conventional compressor impeller including a disk portion having blades as plate elements.

FIG. 6 is a centrifugal stress analysis result obtained by analyzing a conventional blade using solid elements.

FIG. 7 shows an example of centrifugal stress analysis according to the method of the present invention in which the entire compressor impeller with all the blades is analyzed using solid elements.

FIG. 8 is a centrifugal stress analysis result obtained by analyzing a conventional blade using a plate element.

FIG. 9 is a result of centrifugal stress analysis by a method of the present invention in which a blade is analyzed as a solid element.

FIG. 10 is a diagram illustrating first to third modes in eigenvalue analysis of a blade.

FIG. 11 is a diagram showing structural analysis software and its use classification.

FIG. 12 is a diagram illustrating an impeller shape determination process.

 ────────────────────────────────────────────────── ─── Continuation of the front page (72) Inventor Natsuko Matsuura 3-2-16 Toyosu, Koto-ku, Tokyo Ishikawajima Harima Heavy Industries, Ltd. Tokyo Engineering Center F term (reference) 3G002 BA00 BB02 3G005 FA13 FA41 GB77 JA16 JA40 5B046 AA00 DA02 GA01 JA08

Claims (3)

[Claims] 1. A structural analysis method for a rotating machine, wherein a design is performed in three dimensions, the design data is directly used for a structural analysis using a computer, and the analysis result is evaluated and fed back to the design. . 2. Using a structural analysis program for creating a meridional plane shape and a blade shape instead of a plate element, defining a meridian shape of an impeller and a blade shape made up of a point group by a solid model,
A rotary machine that automatically divides the meridional plane shape and the wing shape of the solid model into a plurality of meshes using a solid FEM data automatic creation program dedicated to an impeller, performs structural analysis on the meshes, and displays a result as an image. Structural analysis method. 3. A method for analyzing the structure of a rotating machine, comprising inputting final constraint conditions such as a stress value and a displacement, and obtaining an optimum shape satisfying the conditions.