Classification and Control of Key Factors Affecting the Failure of Aviation Piston Turbocharger Systems Using Model-Based System Safety Analysis

Mengyao Bao,Guo Li,Shuiting Ding,Adel Ghenaiet

doi:10.1155/2021/9710515

Abstract

Turbocharging is an effective way to address the problem of reduction in power and increase in fuel consumption of aviation piston engines during high-altitude flight. However, turbochargers have greatly increased the degree of complexity of power systems. The model-based system safety analysis methods for the safety analysis of turbocharging systems are introduced in this study to overcome the limitations of the traditional safety analysis methods regarding complex matching and coupled safety issues. On the basis of the established system models and the formed failure mode work boundaries and safety boundaries, the column profile coordinates F of correspondence analysis with the numerical deviation of the key factors are used to identify the key factors affecting failure, thereby proposing safety control strategies in a targeted manner. Then, the failure probability of the turbocharging system is assessed through the Monte Carlo method. System failure modes and probabilities before and after the execution of safety control strategies are compared to accurately determine the effectiveness of those strategies. The verification examples show that a safety control strategy that adjusts the diameter of the wastegate e 2 can reduce system failure probability and enhance safety level.

Highlights

Aviation piston engines are an important option for general aircraft power and account for the absolute majority in the market
Regarding the difficulty in identifying the mutually coupled failure modes caused by the complex matching connection between the turbocharger and the engine, the model can be an effective tool in the system safety analysis and design process, overcoming the limitations of traditional safety analysis methods
After the safety control strategy is used, the failure probability of the system limit state function GðEÞ corresponding to the safety margin of each work boundary is lower, where the largest decrease occurs in the failure probability of the failure mode for excess revolution of the turbocharger rotor

Summary

Introduction

Aviation piston engines are an important option for general aircraft power and account for the absolute majority in the market. Regarding the difficulty in identifying the mutually coupled failure modes caused by the complex matching connection between the turbocharger and the engine, the model can be an effective tool in the system safety analysis and design process, overcoming the limitations of traditional safety analysis methods. In connection with the characteristics of the model-based system safety assessment process, the key components in the corresponding system safety analysis methods are as follows: (1) establishment of the system model, (2) description method for the work boundaries and safety boundaries of the failure modes, (3) classification method for the key influencing factors acting on the failure modes, and (4) proposal and verification of the safety control strategies Detailed discussions of these components are presented in the subsequent sections according to the aforementioned order

Establishment and Verification of the System Simulation Model

Design

Safety Boundary Description Method for the Failure Modes

Safety Control Strategies and Verification for the Key Influencing Factors

Findings

Conclusion