New optimum configuration for the FGM rotating disc in gas turbines using combined thermal-mechanical analysis: An analytical approach

Abstract

The gas turbine is one of the most suitable equipment for various applications. Usually, a gas turbine comprises a set of discs to maintain turbine blades. The rotating disc in gas turbines is one of the critical components affected by various thermal and mechanical loads. The current article considers a new rotating disc with variable thickness (power-law profile). The functionally graded material has been used as the disc material, and the disc’s properties vary with temperature and location. Therefore, the mechanical and thermal behaviours of the disc are a function of temperature and location. The differential energy balance equation has been derived for analysing the new disc. In the performed analysis, the conduction and convection heat transfer coefficients vary with temperature and location; thus, the derived final heat transfer equation has high nonlinearity. One of the efficient expansion methods, the so-called Differential Transformation Method (DTM), is used for the governed equation’s analytical solution, and the numerical solution is used for validation. Then, the stress analysis is performed using analytical expressions according to the temperature profile. The impacts of geometrical and thermophysical characteristics on the temperature and stress distribution are evaluated using the analytical solution in the new disc. The comparison of displacement and stresses in the new FGM disc and old discs shows that the thermo-mechanical performance of the new proposed disc is improved significantly.