Table of Contents
3.1.2 Typical component problems in the compressor: causes and remedies
It’s just unsatisfactory for many car owners to hear, ‘it is the engine’, or ‘the brakes are not working’. When a problem arises, the operator also likes to make his own picture of the technical problems of his „friend“. So he can understand and evaluate the consequences and control those specific.The requisites for this will be outlined in the chapters that describe typical problems of the parts of the gas turbine components in question.
The compressor is especially sensitive for damages and changes ( "Ill. 3.1.1-2") at aerodynamic active (blades and vanes) and/or the flow guiding surfaces (casings). There are some reaons:
- Contrary to the turbine, the compressor has to feed energy into the gas-/airflow. Its effektivity, e.g., efficiency reacts especially sensitive to influences that act obstructive. Thereto count roughness, change of profiles and the widening of tip gaps ( "Ill. 3.1.1-3").
- Based on the compression, the blades and vanes become smaller as the flow cross section decrease to the end of the compressor. The more filigree the blading, the more mechanical sensitive is it. Therefore, when a fracture of a blade occurs the OODs (own object damage) and/or its fragments release a snowballing growth of the damage downstream.
- The rising pressure causes a thinner boundary layer on the surface of the blades of the following stages in flow direction. So the sensitiveness grows with the roughness. This becomes negativ remarkable when the roughness tips breake through the laminar boundary layer.
For those reasons it is understandable that the blade profile, blade roughness and the tip gaps should not change as possible over the operation time.