Effects of Solid Particle Ingestion Through an HP Turbine

Abstract

Modern gas turbines operate in severe dusty environments, and because of such harsh operating conditions, their blades experience significant degradation in service. This paper presents a numerical study of particle dynamics and erosion in an hp axial turbine stage. The flow field is solved separately from the solid phase and constitutes the necessary data in the particle trajectories simulations using a Lagrangian tracking model based on the finite element method. Several parameters consider a statistical description such as particle size, shape and rebound, in addition to the turbulence effect. A semi empirical erosion correlation is used to estimate erosion contours and blades deteriorations, knowing the locations and conditions of impacts. The trajectory and erosion results show high erosion rates over the pressure side of NGV near trailing edge, in addition to extreme erosion observed toward the root corner, due to high number of particles impacting with high velocities. On the suction side, erosion is mainly over a narrow strip from leading edge. Erosion in the rotor blade is shown along the leading edge and spreading over the fore of the blade suction side, owing to a flux of particles entering at high velocities and incidence. On the pressure side, regions of dense erosion are observed near the leading edge and trailing edge as well as the tip corner. Critical erosion spots seen over NGV and rotor blade are signs of a premature failure.