A Top-Down Approach for Quantifying the Contribution of High Pressure Compressor Deterioration Mechanisms to the Performance Deterioration of Turbofan Engines

Abstract

Maintenance costs are a substantial contributor to airline operating costs. In this context, understanding, analyzing, and predicting engine performance deterioration is crucial. While diagnostic methods for analyzing the current module and overall engine condition are established in state-of-the-art engine condition monitoring (ECM) systems, deterioration modeling and prognosis are still fields of research. The identification of the contribution of deterioration mechanisms, such as fouling, erosion, and abrasion, to the in-service deterioration poses a key challenge in this area. This paper focuses on a top-down approach for the high pressure compressor (HPC) module. The selected approach is to quantify the contribution of individual deterioration mechanisms to the overall HPC efficiency deterioration based on in-flight measurements. This is accomplished by first using the in-flight measurements to analyze the HPC efficiency loss. Then, the resulting time series of the analyzed HPC efficiency loss are preprocessed. Finally, models of the deterioration mechanisms are fitted to the preprocessed time series. The deterioration models are chosen based on literature references to the respective deterioration mechanisms. As multiple influencing factors affect the deterioration mechanisms, a fleet analysis is conducted to select the model inputs. The fitting process involves a parametric nonlinear regression problem. The outcome is an estimation of the evolution of the deterioration mechanisms over time. This methodology is used to evaluate all available in-service engines of the same type and fleet and to define a fleet model. In the final step, benefits and limitations of the fleet model are investigated.

A Novel Process Chain for the Automated Repair of Leading Edges in Aircraft Engines

“…(4) no clamping deviation, (5) simplified data processing, (6) transport routes and planning are not necessary, and. (7) no expensive measuring machine is required.…”

“…The wear mechanisms are also generally superimposed by manufacturing scatter and, possibly, previous repairs of the components. [6,7] Given the various locking mechanisms in the operation of moving blades with simultaneously expected long service life, the maintenance of the blades plays an important role [7]. At regular intervals and after special events, e.g., a bird strike, moving blades are inspected and individually repaired depending on the degree of damage.…”