The Numerical Simulation Of Stress Field In A Turbine Blade With TBCs Based On Fluid-solid Coupling Method

Due to the property of high temperature resistance, thermal barrier coatings are extensively applied in turbine blade of aircraft engines. But the failure of TBCs severely constraints the life of aircraft engine. Thus,that is essential for the improvement of turbine blades’ service life to understand the failure mechanism.Obviously,The high temperatures and stress concentrations act as the local sources of damage initiation and defects propagation in the form of cracks. This paper simulates the stress distribution and temperature field by using the fluid-solid coupling method.The research content and results are illustrated as follows:(1) The fluid-solid coupling theory of turbine blade with TBCs has been built.The turbulent core region of fluid domain is governed by N-S equations, while the wall boundary layer region will not be solved directly but specify the value of field variables with semi-empirical formula.In solid domain, the CHT theory is applied in the procedure of computing temperature distribution, which is used as predefined field variable to compute elastic-plastic stress distribution. At the fluid-solid interface, the temperature and heat flux continuous boundary conditions are applied.(2) The fluid-solid numerical simulation approach of turbine blade has been achieved by using ABAQUS code to solve solid domain and FLUENT code to solve fluid domain. At the same time, the MPCCI code is chosen as the third software to exchange the value of variables between these two domains. During the pre-process of solid model,the geometry of turbine blade is constructed with consideration of the multilayer TBCs’ complexity, and the mesh of TBCs is dominated by quadrilateral element, while some triangular elements exist for the smooth.In fluid domain, the structural-mesh-technique has been adopted to improve the mesh quality. During the numerical procedure, specifying the temperature boundary condition of the fluid domain with the wall temperature calculated from the solid side satisfies the temperature continuity. Specifying the heat flux boundary condition of the solid temperature field with the value calculated from the fluid domain satisfies thn,。e heat flux continuity condition. In this way, heat flux continuity is iteratively enforced at the fluid/solid interface during flow-field and heat conduction conjugate calculations(3) The stress distribution and temperature field of turbine blade within service procedure have been presented.During the steady period, temperature at the leadingedge and trailing edge is higher than that at other sites, peaking at 1035 °C.In addition,temperature at pressure side is higher than that at the suction side. The value of circular stress in TGO ranges from 1.12 GPa to 3.75 GPa, which at the suction side and pressure side is higher than that at other sites. After cooling, the value of circular stress in TGO ranges from 250 MPa to-3.5 GPa. the stress level at leading edge and trailing edge is dramatically higher than that at other sites.In sum, this work achieved the transient fluid-solid coupling. simulation of stress distribution and temperature field in turbine blade with TBCs. which is used to be the source for predicting possible failure region in turbine blade with TBCs.