Experimental and Numerical Investigation of Erosive Change of Shape for High-Pressure Compressors

Abstract

Compressor performance and maintenance characteristics of jet engines are highly influenced by erosion caused by ingested, solid particles. For a meaningful prediction of these characteristics, an adequate modeling of the erosive change of shape of compressor blades is necessary. This article investigates the erosive change of shape of two different specimens (cylinder and compressor blade) out of aluminum alloy EN AW-6060 both experimentally and numerically. The erosion experiments were performed with a test rig using different amounts of standardized Arizona Test Dust A3 (particle sizes of 1–120μm) to acquire the time-dependent change of shape of the specimens. The shape of the specimens was digitized using a strip projection technique before and after each erosion test. The test rig provides boundary conditions specific for first stages of axial high-pressure compressors of jet engines in terms of relative fluid velocity (350ms−1) which is the main parameter of erosion. Numerical results were obtained with a model predicting the time-dependent change of shape of the specimens in 2D. The numerical model uses erosion rate curves that were experimentally determined in the same test rig using flat plates out of the aforementioned aluminum alloy. Thus, we were able to investigate experimentally the time-dependent erosive change of shape of the specimens and compare it with the numerical predictions. We conclude that the numerical model is a valid approach to predict erosive change of shape for different specimen geometries and materials, when erosion rate curves are available for these materials.