Numerical Study On Thermal Shock Of Turbine Guide Vane Considering Thermoelasticity Coupling Effect

Turbine guide vane long-term work in high temperature and pressure of the harsh environment,and it is subjected to the aerodynamic load and thermal shock load interaction.It is of great significance to study the numerical simulation of the temperature field and the stress field of turbine guide vanes during the take-off of an aircraft,which is of great significance to the analysis of thermal fatigue and life prediction.Firstly,based on the theory of Helmholtz free energy,the thermal shock problem of one-dimensional infinite plate was solved analytically,and the numerical simulation and comparative analysis were respectively carried out for considering the thermo-elastic coupling effect and ignoring the thermo-elastic coupling effect.The results show that the numerical results of considering the thermo-elastic coupling effect are more approximate to the analytic solution,and the temperature error is reduced by 5%-50%.Moreover,the numerical simulation and comparative analysis of heat shock process of plate under different heat transfer coefficients and temperature difference are carried out,and the applicability of numerical calculation method considering thermos-elastic coupling is studied.The results show that when the convection heat transfer coefficient increases,the temperature error decreases first and then increases,and the stress error decreases.The larger temperature difference between the external environment and the slab,the smaller the error of the numerical simulation considering the thermo-elastic coupling effect,the more obvious the advantage.On this basis,the numerical calculation method of turbine guide vane considering the thermo-elastic coupling effect was established and compared with the unidirectional coupling results.The results show that the temperature oft the leading edge and the trailing edge of the blade rises the fastest during the starting process of the engine,and the stress concentration of the trailing edge is more severe.Comparing with the single coupling results,it is concluded that the temperature rise rate of the blade decreases and the leaf stress peak shifted backward after considering the thermo-elastic coupling effect,and the temperature calculation considering the thermo-elastic coupling effect is closer to the experimental value.Finally,the calculation method was used to calculate the turbine guide vane under different flow field pressure difference and temperature difference.The conclusions are as follows: With the increase of pressure difference,the temperature increases slowly,the stress peak increases,the duration of stress is lower,and when the temperature is steady,the stress decreases with the increase of pressure difference.Using the temperature field data with the increase of temperature difference,a recursive empirical formula of temperature is established.Compared with the numerical results,the error is less than 3%.Except for the initial error,the numerical error is less than 5 ‰.