UQ Lab

Research

• Robust Design of a Compressor Blade under Fouling Conditions:

Fouling and erosion are two problems that severely affect gas turbines. The shape of the blade, its roughness and its structural stability can vary as a consequence of these phenomena. The outcomes of this occurrence can span from the efficiency reduction to the engine shut down according to the nature of the material ingested, to the concentration of contaminant in the air and to the particular design of the machine.
Fouling is related to the deposition of material on the surface of blade and annulus. If the machine under investigation is a heavy duty gas turbine it is likely the problem to occur on the compressor. Indeed, if the presence of impurity in the fuel is not taken into account, the cold section of the component is usually regarded as the most sensible to this phenomenon. In this scenario, the reduction in the overall machine efficiency is to be expected. Usually, it is considered that the 80% of all gas turbine losses accumulated during the operation is due to fouling. This efficiency drop can only be recovered by disassembling the machine and washing it. The on-line washing can help slowing down such degradation.  
In the aero-propulsion field, the size of the particles that are involved in this problem is usually higher, since the absence of filtering system allows for the ingestion of bigger contaminants. In this framework, the component which is affected the most by this problem (due to the usual turbine inlet temperature) is the first vane of the high pressure turbine.  If the problem manifests, the only way to recover from it is by flying away from the volcanic ash and moving the throttle to idle: the differential thermal expansion coefficient will cause the build up to shed away from the blade. Nonetheless the blade would report severe damages from the occurrence of the problem.
There is therefore a strong need for improving the capability of designing blades keeping into account the degradation problem. In this work, an axial compressor airfoil is modified according to the requirement of less sensibility to the phenomena above mentioned. The robust design of the blade is therefore achieved, in order to minimize the effects of deposition on the performance.

• Validation, optimization and uncertainty quantification of a bend pipe: presentations_download
  

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