Blade root structure optimization method of dimensionality reduction simulated annealing algorithm

Abstract

The invention discloses a blade root structure optimization method of a dimensionality reduction simulated annealing algorithm. The method includes the steps that firstly, a design variable in the optimization process is determined, and two-dimensional parameterization modeling and three-dimensional parameterization modeling of a target blade are completed; secondly, an N0 set of design variables is randomly generated, an initial average value mu0 and an initial standard deviation delta0 of maximum stress value relative errors of a two-dimensional model and a three-dimensional model under the N0 set of design variables are calculated through a finite element method; thirdly, according to a computation result of the three-dimensional finite element model, the blade root is optimized through the simulated annealing algorithm, a dimensionality reduction rule is introduced according to the initial average value mu0 and the initial standard deviation delta0 of the relative errors in the Metropolis sampling process, the finite element computation amount is reduced, and the average value and the standard deviation of the relative errors is updated after three-dimensional model computation is conducted; when the annealing temperature is lower than a set value or a target function value is stable, the computation process is converged if the result is verified to be within a permissible error range, and optimization is completed. The method has the advantages of being high in convergence speed, capable of saving computation resources and time and the like.

Description

technical field [0001] The invention relates to the field of steam turbine blades, in particular to a blade root structure optimization method. Background technique [0002] With the continuous development of my country's thermal power units in the direction of large capacity and high parameters, the safety and reliability of steam turbines have been paid more and more attention. For steam turbine blades that have been in high temperature, high pressure and harsh environment during operation, the blade root is the connecting part that is installed and fixed on the impeller or the rotating shaft, and bears the huge centrifugal force and other loads of the blade. When the stress on a certain part of the blade root exceeds the material limit, it may cause the blade to break and cause the turbine to fail, resulting in huge economic losses. Therefore, it is necessary to improve the blade root structure to reduce its stress level and improve the operating reliability of the unit. ...

AI Technical Summary

Problems solved by technology

[0004] The purpose of the present invention is to provide a leaf root structure optimization method of dimensionality reduction simulated annealing algorithm. By introducing dimensionality reduction criteria, two-dimensional and three-dimensional finite element models are used for cross-validation in the simulated annealing optimization process. Element calculation replaces three-dimensional finite element calculation, which can solve the problems of slow convergence and long time consumption in the current leaf root optimization method

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