CN-122020901-A - Novel ship gas turbine compressor blade vibration stress optimization method

CN122020901ACN 122020901 ACN122020901 ACN 122020901ACN-122020901-A

Abstract

The invention relates to the field of gas turbines, in particular to a novel method for optimizing vibration stress of a compressor blade of a ship gas turbine, which comprises the steps of carrying out vibration stress simulation analysis on a constructed finite element simulation model to obtain definition data of a vibration stress concentration position, and then, the association of the stress concentration position and the geometric characteristics of the blade profile is completed, blade-type modeling coefficient data of each sensitive section are obtained, the sensitive section range is positioned, a standard-reaching aerodynamic performance evaluation report and an intensity vibration analysis report are output, and the final blade structure is formed through integration and optimization. Compared with the methods of redesigning, optimizing, adjusting the mounting angle of the profile of the blade and the like, the method not only maintains the excellent aerodynamic performance of the original blade inlet profile, but also can meet the requirement of blade vibration stress distribution optimization, thereby improving the fatigue resistance of the blade.

Inventors

ZHANG LIANG
LIU YUNNING
LI DONG
SUN YONG
QU LINWEI

Assignees

中国船舶集团有限公司第七〇三研究所

Dates

Publication Date: 20260512
Application Date: 20260202

Claims (9)

1.A novel method for optimizing vibration stress of a compressor blade of a ship gas turbine, which is characterized by comprising the following steps: S101, constructing a finite element simulation model based on basic design data of a target ship gas turbine compressor blade, introducing operation parameters of a gas turbine, and carrying out vibration stress simulation analysis on the constructed finite element simulation model after applying equivalent load to obtain definition data of a vibration stress concentration position; S102, based on the obtained definition data of the vibration stress concentration position, completing the association of the stress concentration position and the geometrical characteristics of the blade profile, dividing the standard and the range of the modeling coefficient, and obtaining the blade-type modeling coefficient data of each sensitive section; S103, positioning the sensitive section range based on definition data of vibration stress concentration positions and leaf modeling coefficient data of each sensitive section, modeling thickening the sensitive section and calculating thickened leaf type critical dimensions to obtain locally optimized thickened leaf type data and thickened leaf type critical dimension parameters; S104, carrying out aerodynamic performance evaluation and intensity vibration analysis based on the locally optimized thickened leaf profile data and thickened leaf profile critical dimension parameters, if any index does not reach the standard, returning to the S102, repeating the operation after adjusting the modeling coefficient until all indexes reach the standard, and finally outputting a standard-reaching aerodynamic performance evaluation report and an intensity vibration analysis report; S105, combining the standard-reaching aerodynamic performance evaluation report, the intensity vibration analysis report, the locally optimized thickened blade profile data and the thickened blade profile critical dimension parameters, and integrating and optimizing to form a final blade structure.
2. The method for optimizing the vibration stress of the novel ship gas turbine compressor blade according to claim 1, wherein the basic design data of the target ship gas turbine compressor blade in S101 comprises a blade type three-dimensional geometric model, blade material mechanical parameters and blade installation boundary conditions; the operation core parameters of the gas turbine comprise design rotation speed, air inlet temperature, air inlet pressure and working medium flow under typical working conditions; Grid division is carried out based on the three-dimensional geometrical model of the blade profile, refined grids are adopted for the region with concentrated stress, transition grids are adopted for other regions of the blade body, constraint conditions are defined in the model based on the actual installation state of the blade, and equivalent loads including centrifugal load, pneumatic load and vibration excitation load are applied in combination with the operation parameters of the gas turbine.
3. The method for optimizing vibration stress of the novel ship gas turbine compressor blade according to claim 1, wherein after an equivalent load is applied, the S101 is characterized in that simulation analysis type is set as transient dynamics analysis, a preset concerned vibration mode is focused, vibration response of the blade in a corresponding mode is solved, vibration stress distribution data of the whole area of the blade are extracted, a stress distribution cloud chart, a stress along-blade-height change curve and a stress along-section circumferential distribution curve are generated, positions with stress values higher than that of peripheral areas and stress gradient abrupt changes are identified by comparing stress values of all areas of the blade, specific position information of the positions is clarified, and definition data of vibration stress concentration positions including a stress concentration area along-blade-height coordinate interval, specific positions along the circumferential direction of the section, stress peaks in the corresponding concerned vibration mode and initial values of stress concentration coefficients are obtained, and the vibration stress concentration positions are determined.
4. The method for optimizing vibration stress of a novel ship gas turbine compressor blade according to claim 1, wherein the step S102 is characterized in that the corresponding blade sensitive section is positioned according to the vibration stress concentration position determined by definition data of the vibration stress concentration position, front-tail edge radius and curvature distribution data of the sensitive section and adjacent sections are extracted, and the correlation between the stress concentration position and the blade geometry is completed according to the front-tail edge radius and curvature distribution data to define the correspondence between the front-tail edge radius, curvature change rate and stress concentration coefficient.
5. The method for optimizing vibration stress of a novel ship gas turbine compressor blade according to claim 1, wherein the step S102 is implemented by taking key geometric parameters of a blade profile front and tail edges of sensitive sections as modeling and amplifying reference dimensions, combining initial values of stress concentration coefficients and aerodynamic performance constraints, defining modeling coefficient ranges of the sensitive sections, completing division of modeling coefficient references and ranges, and obtaining blade-type modeling coefficient data of the sensitive sections, wherein the obtained blade-type modeling coefficient data comprise estimated values of modeling and amplifying reference dimensions, finally determined modeling coefficients, modeling and amplifying directions and radius of the front and tail edges after amplification of each sensitive section.
6. The method for optimizing vibration stress of the compressor blade of the novel ship gas turbine according to claim 1, wherein after the sensitive section range is positioned in the step S103, a molded thickened sensitive section set is obtained, and based on original blade profile coordinate data and a determined molding coefficient and an amplifying direction, the blade profile of each sensitive section in the sensitive section set is uniformly amplified and molded, specifically, for a leading edge elliptic section and a trailing edge circular arc section, the curvature radius is synchronously amplified according to the molding coefficient, and for a blade straight line section or a curved line section, the corresponding distance is translated along the normal direction of the molded line; And (3) extracting the maximum thickness, the front edge radius and the tail edge radius of each thickened sensitive section, comparing the maximum thickness, the front edge radius and the tail edge radius of each thickened sensitive section with the original blade profile, and recording size change data to obtain locally optimized thickened blade profile data comprising the coordinates of the complete blade profile of each thickened sensitive section, and the key size parameters of the thickened blade profile including the maximum thickness, the front edge radius and the tail edge radius of each sensitive section and the size change quantity of the original blade profile.
7. The method for optimizing vibration stress of a novel ship gas turbine compressor blade according to claim 1, wherein the step S104 is characterized in that a compressor runner calculation domain containing thickened blade shapes is constructed, after grid division is carried out on the calculation domain, pneumatic simulation boundary conditions are set, a turbulence model suitable for turbomachinery is selected to solve flow field distribution under design working conditions, wherein the pneumatic simulation boundary conditions comprise that a total temperature and total pressure boundary is set on an air inlet side, a static pressure boundary is set on an air outlet side, an adiabatic non-slip boundary is set on the surface of the blade, actual efficiency, flow, pressure ratio and surge margin with the thickened blade shapes are obtained through solving, and compared with original design indexes, so that pneumatic performance evaluation is completed.
8. The method for optimizing vibration stress of the novel ship gas turbine compressor blade according to claim 7 is characterized in that after the pneumatic performance evaluation, based on thickened blade profile data, a finite element simulation model is updated, the constraint condition and equivalent load application of S101 are adopted, and the vibration simulation of the strength is developed, specifically, the static stress distribution and fatigue life of the blade under steady-state working conditions are calculated, the magnitude of static stress and material yield strength, the magnitude of fatigue life and design requirements are verified, and the strength analysis is completed; Solving the natural frequency and vibration stress distribution of the thickened blade profile, verifying the vibration stress and the maximum allowable vibration stress, and completing vibration analysis; when any index of the intensity analysis, vibration analysis and pneumatic performance evaluation does not reach the standard, repeating the operation after adjusting the modeling coefficient; When all indexes of the intensity analysis, vibration analysis and aerodynamic performance evaluation reach the standard, outputting flow field distribution data containing flow field distribution data and actual aerodynamic performance parameters and intensity vibration analysis reports containing static stress distribution, fatigue life calculation results, natural frequency data, vibration stress distribution and stress concentration coefficient improvement values.
9. The method for optimizing the vibration stress of the compressor blade of the gas turbine of the ship according to claim 1, wherein S105 integrates the thickened profile coordinates of each sensitive section and the original profile coordinates of the non-sensitive section in the locally optimized thickened profile data and thickened profile critical dimension parameters according to an original stacking rule, performs global geometric optimization on the integrated profile, optimizes the molded lines in the transition areas of the sensitive section and the non-sensitive section by adopting a curve interpolation method, and obtains optimized profile data; based on the optimized blade profile data, a complete three-dimensional solid model of the blade is generated, complete design data of the final blade is extracted, optimization of the vibration stress of the blade is completed, and the final blade structure is formed through output.

Description

Novel ship gas turbine compressor blade vibration stress optimization method Technical Field The invention relates to the field of gas turbines, in particular to a novel ship gas turbine compressor blade vibration stress optimization method. Background When the current novel gas turbine compressor blade is designed, a high-performance compressor blade profile is adopted, but the phenomenon of blade vibration stress concentration is serious, and the problems that the fatigue performance of the blade is not up to the design expectation and the blade breaks prematurely occur in the blade fatigue test process are caused. Aiming at the difficulty, the design of the compressor blade often adopts methods of directly redesigning the blade profile, simply increasing the size of a blade transfer fillet or adjusting the mounting angle of the blade profile, and the like to carry out optimization work. However, it is thought that the new and satisfactory blade profile is obtained by these methods, and a number of iterations are typically performed, balancing back and forth between performance and vibration stress, with very low design efficiency, and unsatisfactory end results. On the premise of ensuring that the performance molded line function of the blade is unchanged, the vibration stress distribution is rapidly optimized, so that the fatigue performance of the blade is a key technology which needs to be solved at present, and the requirements of the vibration reliability and the aerodynamic performance of the blade are further met. Disclosure of Invention Aiming at the technical problems existing in the prior art, the invention provides a novel ship gas turbine compressor blade vibration stress optimization method. The technical scheme for solving the technical problems is as follows, the novel ship gas turbine compressor blade vibration stress optimization method comprises the following steps: S101, constructing a finite element simulation model based on basic design data of a target ship gas turbine compressor blade, introducing operation parameters of a gas turbine, and carrying out vibration stress simulation analysis on the constructed finite element simulation model after applying equivalent load to obtain definition data of a vibration stress concentration position; S102, based on the obtained definition data of the vibration stress concentration position, completing the association of the stress concentration position and the geometrical characteristics of the blade profile, dividing the standard and the range of the modeling coefficient, and obtaining the blade-type modeling coefficient data of each sensitive section; S103, positioning the sensitive section range based on definition data of vibration stress concentration positions and leaf modeling coefficient data of each sensitive section, modeling thickening the sensitive section and calculating thickened leaf type critical dimensions to obtain locally optimized thickened leaf type data and thickened leaf type critical dimension parameters; S104, carrying out aerodynamic performance evaluation and intensity vibration analysis based on the locally optimized thickened leaf profile data and thickened leaf profile critical dimension parameters, if any index does not reach the standard, returning to the S102, repeating the operation after adjusting the modeling coefficient until all indexes reach the standard, and finally outputting a standard-reaching aerodynamic performance evaluation report and an intensity vibration analysis report; S105, combining the standard-reaching aerodynamic performance evaluation report, the intensity vibration analysis report, the locally optimized thickened blade profile data and the thickened blade profile critical dimension parameters, and integrating and optimizing to form a final blade structure. In a preferred embodiment, the basic design data of the gas turbine compressor blade of the target ship in S101 specifically includes a three-dimensional geometric model of a blade profile, including complete coordinates of a leading edge, a trailing edge, a suction surface and a pressure surface along each section of a blade height, mechanical parameters of blade materials, elastic modulus, poisson ratio, density, fatigue strength and the like, a blade installation boundary condition, a connection mode with a wheel disc, a constraint position and a constraint type; the operation core parameters of the gas turbine comprise design rotation speed, air inlet temperature, air inlet pressure and working medium flow under typical working conditions; Grid division is carried out based on a blade profile three-dimensional geometric model, refined grids are adopted for areas, such as blade roots, transfer fillets and the like, where stress concentration is easy to occur, transition grids are adopted for other areas of a blade body, constraint conditions are defined in the model based on the actual installation state of the blade, such as fi