Gas turbine blade failure scenario due to thermal loads in case of Nickel based super alloys

Abstract

Gas turbines are used in power generation and transportation. Turbine blades are subjected to high thermal loads and are getting damaged due to the same leading to power shutdowns. Detection of stresses in the early stage will reduce such problems of failure. Earlier, researchers tried to study about different materials for their usage as blade. In this work, turbine blade with fir-tree region is modeled and analyzed using Ansys 17.1. Speed, turbine inlet temperature and pressure, material properties are given as conditions before running it in the solver. For various super alloys like Udimet-700, IN-792, Rene-41 and Mar-M-200, deformation in the blade, equivalent stresses and strains are drawn and analyzed. Also, variation of thermal stresses with change in temperature and pressure are compared. Overall, the turbine blade failure scenario is observed for different conditions in all the materials under study. It is found that the stresses and strains are more near the base of the blade and in the top portion of the root. Total deformation, equivalent stress and strain are less for Mar-M-200. But, thermal stresses at the peak temperature and pressure are demonstrably less for IN-792. This means, in structural point of view, Mar-M-200 is beneficial with more resistance to deformation, stress and elongation and as per the thermal aspects, IN-792 is good. Overall, Mar-M-200 is really advantageous as the stresses obtained due to varied temperatures and pressures are minimum. Thus the present work is beneficial in identifying suitable Nickel based super alloys as gas turbine blade material in order to avoid the frequent turbine blade failures and much needed maintenance.