The failure in a microturbine cogeneration system originated from the seizure of the gas bearing following a transient loss of hydrodynamic air support flow. This case reveals the sensitivity of these systems to disturbances in the pneumatic supply. PolyWorks was used for precision scanning and Autodesk Fusion for parametric modeling of the affected surfaces in the forensic analysis and 3D reconstruction of the damage.
Digital damage reconstruction with PolyWorks and Fusion 🔧
The 3D pipeline began with scanning the surface of the journal and seized bushing using a laser arm, processing the point clouds in PolyWorks to align geometries and detect metal-to-metal contact zones. The data was exported to Autodesk Fusion to generate a parametric solid model that allowed simulating wear and material transfer. A localized annular seizure pattern was identified, indicative of a momentary collapse of the air film, followed by high-speed rotary contact that fused the surfaces.
When the air takes a break and everything melts 🔥
The gas bearing, designed to float without friction, decided to take a vacation just when its air film was needed most. The result was a seizure so intimate that the journal and bushing seemed to want to be one piece forever. As if the maintenance manual said: if the flow fails, embrace the shaft and never let go. Good thing PolyWorks and Fusion came to the rescue to document the forced separation.