An MBSE-Based Scenario-Function Framework for Reliability Design of Turboshaft Aero-Engines

Traditional reliability design methods for aeroengines primarily depend on empirical approaches and physical validation, leading to inadequate integration between functional requirements and actual system implementation. To address this issue, this paper proposes an innovative Model-Based Systems Engineering (MBSE) analysis framework characterized by a clear 'scenario-function-subsystemcomponent' linkage, specifically tailored for reliability design in turboshaft aero-engines. Unlike traditional methods, which often rely on reverse validation and lack systematic traceability, this framework leverages SysML modeling tools to construct a structured and scenario-driven modeling chain from operational scenarios down to physical components. First, comprehensive scenario modeling is achieved using Use Case Diagrams and Activity Diagrams to represent typical turboshaft engine operating conditions, explicitly linking scenarios with system functions. Subsequently, these functions are systematically decomposed through detailed Functional Modeling into specific subsystems and critical physical components, establishing complete traceability. This approach overcomes the limitations of traditional reverse verification methods as well as the common drawback of other MBSE approaches that often remain at abstract functional or subsystem levels. It provides a reusable methodological framework for model-based reliability design of turboshaft engines, applicable to early-stage requirement capture and system architecture optimization in multi-model engine development.