BLADE EROSION MEASUREMENT SYSTEM
Developed in partnership with the french aero engine manufacturer TURBOMECA (SAFRAN GROUP), this patented system allows to measure, on-wing, the wear by erosion of blade leading edges on helicopter turbines.
Defects likely to affect integrity of blade leading edges on a helicopter turbine arise from two types of incidents:
• Foreign body ingestion by turbine can result in material loss from blade leading edges. Measurement of this damage can be achieved using an ARGUS 900 probe fitted with a distal stereo tip, connected to a TIVE 900 MK2 unit running the 3DSIZER tridimensional software. Depending on the number and dimensions of these defects, an on-wing “Blending” operation can be carried out or decision is made for engine removal leading to blade replacement in shop.
• Ingestion by the turbine of a multitude of abrasive particles can in itself result in regular erosion of leading edges of all blades on the engine stage. This is essentially seen on helicopter engines and particularly military machines operating in desert conditions. In this case the “stereo” measurement method is not capable of measuring the degree of blade erosion.
The solution developed by EFER involves modelling a non-eroded blade and then creating a graticule representation which also includes erosion level limits, beyond which an engine removal is necessary. During turbine inspection, this graticule is overlayed on the video image of eroded blades, allowing immediate go / no-go decision.
The equipment developed by EFER and required for such inspection comprises a HTB 900 video probe, strictly specific to the engine stage, associated with its support tool allowing to precisely position the probe and a EVS 900 MK2 operating unit.
HTB 900 VIDEO PROBE
• Characteristics specific to engine stage:
– Mechanical (diameter/length)
– Optical (field and direction of view)
– Dedicated graticule integrated in probe
• Probe rotation control
• Focus adjustment control
• Graticule rotation control
• Integral video-light cable for connectable to the EVS 900 MK2 unit