Turbomachinery affected by environmental solid particles

Wakeman, T.; Tabakoff, W.

doi:10.2514/6.1979-41

Cited by 6 publications

(4 citation statements)

References 1 publication

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“…Later, a hot erosion tunnel was developed by Tabakoff and Wakeman [4] for testing turbine blade erosion that takes place at elevated temperatures. Experimental procedures used to assess erosion and performance degradation are very costly and revealed limited information, because of several operating conditions and applications; instead the numerical simulations become extensively used.…”

Section: Introductionmentioning

confidence: 99%

Effects of Solid Particle Ingestion Through an HP Turbine

Ghenaiet¹

2012

Volume 8: Turbomachinery, Parts A, B, and C

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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.

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Section: Introductionmentioning

confidence: 99%

Effects of Solid Particle Ingestion Through an HP Turbine

Ghenaiet¹

2012

Volume 8: Turbomachinery, Parts A, B, and C

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“…In turbine blades the erosion takes place at high temperature, accordingly, Wakeman and Tabakoff (1979) were the first to build a hot tunnel to test erosion at elevated temperatures. In case of the Nickel based super-alloys, Tabakoff and Hamed (1988) This behavior is experienced even for the small particles released near the hub.…”

Section: Erosion Assessmentsmentioning

confidence: 99%

Prediction of erosion in an axial turbine with initial position of blade

Ghenaiet¹

2019

European Conference on Turbomachinery Fluid Dynamics and Hermodynamics

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Solid particle ingestion is one of degradation mechanisms in gas turbines. This paper aim is to study the solid particle dynamics and induced erosion in an axial turbine. Given that ash particle concentration is typically very low, a one-way coupling Lagrangian approach is adopted for particle tracking. As the location and frequency of impacts, velocity and angle of impingement are determined, the erosion rates and associated mass and geometry deterioration are assessed for different particle concentrations. The results show that the vane pressure side is completely eroded with extreme rates beyond the throat. On the other hand, the rotor blade is eroded along the leading edge extending up to the suction side and the tip corner added to the aft of pressure side. The influence of the initial position of blade on erosion pattern and intensity is also revealed. The eroded profiles may serve in predicting the aerodynamic performance degradation. KEYWORDSAxial turbine; Lagrangian particle tracking; Erosion; Blade profile deterioration; Initial position of blade NOMENCLATURE C D drag coefficient c chord d diameter e particle restitution factor F b buoyancy force F D drag force F S Saffman force g gravity m mass r radius, radial co-ordinate Re Reynolds number t time V f V p fluid velocity particle velocity z axial co-ordinate Greek letters  impact angle (deg)  erosion rate (mg/g)  dynamic viscosity (kg/m.s)  density (kg/m 3 )  speed of rotation (rad/s)  tangential co-ordinate Subscript n p r  z 1, 2 normal particle radial tangential axial at impact and rebound Acronyms CG&E HPT PS SS Cincinnati Gas and Electric Company High Pressure Turbine pressure side suction side

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“…The development of erosion prediction models used in turbomachinery began with the experiments carried by Grant and Tabakoff [2]. Later, a hot erosion tunnel was developed by Tabakoff and Wakeman [3] for testing the turbine blade erosion that takes place at elevated temperatures. Turbomachinery blade erosion has been the subject of many investigations that have shown that the particle characteristics significantly affect the blade impact patterns [4] and consequently the resulting blade erosion.…”

Section: Introductionmentioning

confidence: 99%

Study of Particle Ingestion Through Two-Stage Gas Turbine

Ghenaiet

2014

Volume 2C: Turbomachinery

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This paper presents a numerical study of particle laden gas flow through a two-stage hp axial turbine, by means of an inhouse code based on the Lagrangian tracking model and the finite element method. As fly-ash solid particles trajectories and locations of impacts are predicted, the local erosion rates and the deteriorations of blades are assessed. The computed trajectories provide a detailed description of particles behaviors and reveal that particle impacts on the aft of vane pressure side usually lead to significant variations in the directions of particles to the next rotor blade, and subsequently particles impact the suction side. The plots of equivalent erosion rates indicate the vanes and blades locations which suffer more erosion. The first vane pressure surface is impacted more than any other component, but higher rates are seen at the top corner from trailing edge. The critical regions of erosion wear in the first rotor are observed over the top of blade leading edge extending along the tip as well as a rounding of the top corner from trailing edge. In the second vane, the regions of higher erosion are revealed over the last third of leading edge and the top corner extending along tip. The erosion in the second rotor is over a large area of suction side till the tip corner. The predicted areas of extreme erosion, also shown by the deteriorated profiles, are indicators for anticipated vanes and blades failures. NOMENCLATUREFluid velocity [m/s] Particle velocity [m/s] z Axial coordinate [m] Greek letters β Impact angle [degree] ε Erosion rate [mg/g] Ε q Equivalent erosion rate [mg/s.mm 2 ] & [mg/g.mm 2 ] ρ Density [kg/m 3 ] ω Speed of rotation [rad/s] θ Angular coordinate [rad]

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Turbomachinery affected by environmental solid particles

Cited by 6 publications

References 1 publication

Effects of Solid Particle Ingestion Through an HP Turbine

Effects of Solid Particle Ingestion Through an HP Turbine

Prediction of erosion in an axial turbine with initial position of blade

Study of Particle Ingestion Through Two-Stage Gas Turbine

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