Gas Turbine Tribology

Gas Turbine

-Internal combustion engine-Uses air as the working fluid

Gas Turbine Applications

-Aircraft-Generators-Ships and powerboats-Racing cars

Gas Turbine Tribology Research

Gas turbine roughness-related articles published

Turbine Component Wear

-ErosionSuspended particles with the air intake passing over the compressor section

-High temperature corrosionHigh temperature air fuel mixture in contact with the turbine section

Erosive Wear in Gas Turbine

Erosive wear is caused by the impact of particles of solid or liquid against the surface of an object.

Impingement angle of a particle causing erosion of surface

Severely eroded turbine compressor blades

Erosive Wear in Gas Turbine

Schematic representation of the effect of impingement angle on wear rates of ductile and brittle materials

Erosive Wear in Gas Turbine

Effect of temperature on the erosive wear rate of stainless steel

Erosive Wear in Gas Turbine

-Turbine vane/blade surface deterioration is strongly dependent on the turbine geometry-In common with other forms of wear, mechanical strength does not guarantee wear resistance and a detailed study of material characteristics is required for wear minimization-New blade coatings and materials are continuously being developed to meet the challenging requirements of modern gas turbine engines

Hot Corrosion in Gas Turbine

During combustion sulfur from the fuel reacts with sodium chloride from ingested air at elevated temperatures to form sodium sulfate. The sodium sulfate then deposites on the hot-section components resulting in accelerated oxidation. This is commonly referred as hot corrosion.

Hot corrosion of gas turbine component

Hot Corrosion in Gas Turbine

-Abradable coatings are provided to resist thermal corrosion.-Turbine designers need to decide on a case-by-case basis whether metallic or ceramic abradables should be used

Materials Used in Gas Turbine

Evolution of materials used in gas turbine

Gas Turbine Performance

-Aerodynamic loss.-Thermal/heat loss.

Gas Turbine Performance

Yun et al. conducted performance tests in a low-speed, single-stage, axial flow turbine with roughened blades.

Gas Turbine Performance

J. P. Bonss review article

Lubrication in Gas Turbine

-Bearings-Gears-Other rotating and rubbing components

Any oil used in an aero engine has to be approved for that engine type before it can be used in service

Common lubricating oil grades for gas turbine are:SAE5SAE5W10SAE5W20

Other Gas Turbine Degradations

FoulingCaused by the adherence of particles to airfoils and annulus surface.

DamageCaused by large foreign objects striking the flow path components.

AbrasionCaused when a rotating surface rubs on a stationary surface.

Other Gas Turbine Degradations

Erosion sample from suction surface leadingedge region

Fuel deposition sample from pressure surface trailing edge region

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