# Thermal stress analysis The FEM analyses

2.3. Thermal stress analysis

The FEM analyses were conducted to predict the thermal stress of the combustion liner system using a commercial code, ANSYS v11. The boundary conditions for calculating the thermal stress and strain distributions, such as substrate temperature distributions and environment gas temperature are adopted from our previous work [19].

The thermal stress on the objective materials PI-103 Hydrochloride proportional to the thermal expansion coefficient and temperature difference as presented in the following equation.equation(1)σ=EαΔTσ=EαΔT

The von Mises equivalent stress and strain distributions of the whole combustion liner were obtained. A finite element mesh was created with ANSYS Design Modeler. We conducted grid independent test, and total number of elements was about 300,000.

2.4. Creep life prediction

Creep is well-known as a dominant life-restricting factor of the gas turbine hot components during steady-state operation (base load). Under this operating condition, high temperature and stress are constantly imposed to the substrate thereby the creep lifetime becomes shortened due to the decrease of the creep resistance of the materials even if the substrate is a heatproof material.