Abstract
The damage due to particulate matter ingestion by propulsion gas turbine engines can be significant, impacting the operability and performance of plant components. Here, we focus on the axial compressor whose blades become damaged when operated in dusty/sandy environments, resulting in significant performance degradation. In this work, CFD studies are performed to model the effects of airfoil damage on the first-stage rotor blading of a GE T700–401C compressor. We use thermoplastic additive manufacturing to construct representative physical models of three damage morphologies—ballistically bent/curved leading edges, cragged erosion of leading edges, and eroded leading/tailing edges at outer span locations. The resultant damaged plastic geometries, and a baseline undamaged configuration are then optically scanned and incorporated into sublayer resolved full stage, unsteady RANS analyses. Boundary conditions are imposed that conform to damaged compressor operation protocols, and this iterative process for accommodating corrected mass flow and off-design powering is presented. The results for the three damaged and one undamaged configuration are studied in terms of compressible wave field and secondary/tip flows, spanwise performance parameter distributions and efficiency. A method to estimate the effect of rotor damage on engine SFC is presented. The code, modeling, and meshing strategies pursued here are consistent with a validation study carried out for NASA Rotor 37 — these results are briefly included, and provide confidence in the predictions of the T700 geometry studied. The results provide quantitative comparisons of, and insight into, the physical mechanisms associated with damaged compressor performance degradation.
