Influence of geometrical defects of the blades of turbine and pipelines: numerical study

Abstract

Withstanding of the gas turbine for the elongations is a major consideration in their design because they are subjected to high tangential, axial and centrifugal forces during their working conditions. Several authors have been suggested for the better enhancement of conception, thermal, mechanical and metallurgic properties of blades to withstand these extreme conditions. The damage severely of gas turbine due to the failure of blade, the observation showed that a serious pitting was occurred on the blade surfaces and there were evidences of fatigue marks in the fracture surface We also studied the corrosion of the gas pipe caused by the hydrogen from the high pressure of the turbine. The failure of the blade in a gas turbine was investigated a fracture mechanical study by a numerical analysis. In this study, we used a blade of a gas turbine, with a same shape, and we modified the crack size. In this analysis, the applied pressure is not constant, whereas is imported with an interaction between structure/fluid. So, we used ANSYS® Workbench 16.0 software with the computational fluid dynamics Software (CFD section), a steady state gas flow analysis was carried out, and the pressure distributions. This pressure across the blade is obtained and we mapped these results on the other section of it APDL (ANSYS® Parametric Design Language) section. In the structural analysis a node coordinate where we have the maximum principal stresses were explored. In this node, we have created a semi-elliptical crack and we have compared between them with the Stress Intensity Factors and T-stress values. The second parameter in the Williams' equation give a good information’s on the estimation and the direction of the crack path in the part two we will study Hydrogen play a decisive role in many future energy systems. For these reasons, many researchers have been performed to see the effect of hydrogen on natural gas network.