Chenyu Gan

Safety is essential for sustainable aviation fuels (SAFs). However, evaluating SAFs’ impacts on aero-engine safety is challenging because it involves multiple space scales and the strongly coupled relationships of aero-engine components. Aiming at addressing this problem, a model-based approach is proposed to establish the relationship between the fuel-level physical properties and engine-level safety parameters. Firstly, a unified modeling criterion is proposed to consider the interrelations of aero-engine components. Under this criterion, aero-engine secondary air system (SAS) components are included in SAF safety assessment, since they have non-neglectable influences on aero-engine safety. Secondly, this paper proposes a surrogate-based iteration strategy to embed the combustor’s high-dimensional computational fluid dynamics (CFD) model into the aero-engine flow network model. Then, the proposed model-based safety assessment approach is applied to a Fischer–Tropsch hydro-processed synthesized paraffinic kerosine (F-T SPK) safety assessment case. The effects of fuel flow and blending ratio are considered. The results indicate the necessity to evaluate SAFs’ safety at the aero-engine level and consider the influences of SAS components. The proposed model-based approach may provide a preliminary screening before SAFs’ certification tests. This convenience may be beneficial for reducing the cost and accelerating SAFs’ application.

Sustainable aviation fuels (SAFs) are considered an important solution for reducing carbon emissions. Safety is the most important prerequisite for a new fuel to be used in an aero-engine. As a special component in aero-engines, fuel is required to comply with both airworthiness and technical standards. These two types of standard work together to guide SAF development. In this paper, the SAF safety issues related to aero-engines are first analyzed. Subsequently, SAF-related standard systems are analyzed in detail, and the different safety responsibilities of airworthiness authorities and industry associations are explained. Moreover, the relationships between airworthiness and technical standards are determined from the perspective of actual SAF certification. Furthermore, the revision of the standards is reviewed to summarize the historical evolution and outline the revision intention. Finally, the future SAF certification standards are discussed and prospected, including the blending ratio, property specifications, and testing equipment. According to the discussion, increased safety and fewer constraints are the principal objectives for the development of SAF standards. Analysis, review, and discussion of the SAF standards systems from an aero-engine safety perspective will contribute to the establishment of the next generation of standards to release the fuel potential and improve safety.