Analysis of Environmental Factors and Operating Conditions on Degradation Patterns of Aircraft Systems for Hydrogen-Based Power Generation

Abstract

Currently, one of the most significant challenges in the aviation industry is transitioning towards sustainable aircraft operations. The use of liquefied hydrogen for propulsion and energy supply in aircraft is a recently discussed technology. Due to its novelty in civil aviation, a notable gap exists because the implications of liquid hydrogen storage and hydrogen-based energy supply have not been adequately addressed in assessments of maintenance needs. Theoretical models, such as those based on DIN/ISO standards, often disregard variations in operating conditions and environmental factors, leading to inaccurate estimates of maintenance requirements. This study aims to bridge these gaps by systematically evaluating the impact of various operating conditions and environmental factors on the structural integrity and performance of critical components of hydrogenpowered aircraft. By introducing metrics, parameters, and degradation indices, transfer functions have been developed to link diverse operating conditions and environmental factors with the degradation patterns of various components and to describe different system design approaches. Furthermore, there is a lack of data on how the evaporation of liquid hydrogen and the rate of pressure increase in the tank may impact the degradation of relief valves over time. Therefore, this study proposes a thermodynamic model, developed using MATLAB, to simulate the dynamics of liquid hydrogen evaporation through a computational analysis. This aims to calculate the number of opening and closing cycles of relief valves. This analysis has made it possible to assess how various design variables, types of insulation, insulation degradation, venting pressures, and tank filling levels affect the frequency of relief valve triggers, thus influencing their failure rates. This methodology has facilitated the evaluation of diverse operational scenarios, offering a comprehensive framework for application in various case studies.