Longfei Chen , Aaqib Zafar , Zheng Xu , Shenghui Zhong , Minghua Wang , Yukun Fan , Yang Zhang , Wentao Shi , Xuehuan Hu
{"title":"Comparative analysis of emission reduction and combustion performance in aviation engines: The role of sustainable aviation fuel","authors":"Longfei Chen , Aaqib Zafar , Zheng Xu , Shenghui Zhong , Minghua Wang , Yukun Fan , Yang Zhang , Wentao Shi , Xuehuan Hu","doi":"10.1016/j.paerosci.2025.101172","DOIUrl":"10.1016/j.paerosci.2025.101172","url":null,"abstract":"<div><div>The aviation industry, a cornerstone of global transportation and economic innovation, faces mounting environmental challenges as emissions significantly contribute to climate change and air quality degradation. Sustainable Aviation Fuels (SAFs) have emerged as a transformative solution, offering substantial carbon emission reductions while ensuring operational efficiency. This article integrates scientific rigor—including combustion and emissions analysis—with practical applications such as engine-specific evaluations and policy implications, providing unmatched depth and specificity compared to other SAF reviews. It explores SAF advancements, focusing on American Society for Testing and Materials (ASTM)-certified pathways and their potential to mitigate aviation's environmental impact. SAFs deliver significant reductions in greenhouse gas (GHG) emissions, soot, and particulate matter (PM). SAFs offer lower UHC, CO and CO<sub>2</sub> (life-cycle based) emissions than conventional Jet A fuel due to their cleaner composition and renewable origin. These clean combustion properties position SAF as a critical enabler of sustainable aviation. SAF's superior combustion performance enhances its appeal, improving efficiency, flame stability, and emissions while meeting stringent operational demands. Blend ratios influence engine performance, fuel consumption, and emissions, optimizing thrust and thermal efficiency. Comparative analyses across various gas turbine types, and piston engines confirm SAF's ability to reduce PM, CO<sub>2</sub>, and CO emissions while maintaining operational performance. Despite its promise, SAF adoption faces challenges, including feedstock scarcity, technological and economic constraints, and certification complexities. Operational limitations such as higher specific fuel consumption (SFC) and fuel freezing points highlight the need for policy support, advanced feedstock development, and technological innovation to scale production. SAF adoption is crucial for decarbonizing aviation and transitioning to a low-carbon future, reinforcing its role in achieving a sustainable aviation sector.</div></div>","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"160 ","pages":"Article 101172"},"PeriodicalIF":16.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785531","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Sustainability in Aerospace Additive Manufacturing: current trends and future perspectives","authors":"Ersilia Cozzolino, Ilaria Papa, Valentina Lopresto","doi":"10.1016/j.paerosci.2025.101173","DOIUrl":"10.1016/j.paerosci.2025.101173","url":null,"abstract":"<div><div>Additive Manufacturing (AM) is of paramount relevance in the aerospace industry. That is due to it offering numerous benefits such as complexity of geometries, modeling, prototyping, lightweighting, reduction of material use/waste, and sustainability. From the same perspective, the so-called Smart Manufacturing is gaining great interest: it is an approach integrating cutting-edge technologies, such as AM, with data-driven methods to leverage efficiency, productivity, sustainability, and scalability of processes. It aims to create interconnected manufacturing ecosystems to improve quality, to drive innovation, and to cut costs. Nevertheless, some challenges still exist with AM and its sustainability implications. While several reviews have focused on just AM processes or sustainable aspects of AM for general applications, this one is a comprehensive overview of recent manufacturing approaches, highlighting the need for integrating Artificial Intelligence (AI) and machine learning (ML) techniques with AM process monitoring. As a result, this review will provide insights into the current trends and future developments to help and support decision-making in the aerospace industry from a sustainable perspective.</div></div>","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"160 ","pages":"Article 101173"},"PeriodicalIF":16.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145785532","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Progress in aerospace sciences: A personal retrospective and outlook","authors":"Max F. Platzer (Guest Editor)","doi":"10.1016/j.paerosci.2025.101174","DOIUrl":"10.1016/j.paerosci.2025.101174","url":null,"abstract":"<div><div>The international review journal “Progress in Aerospace Sciences” was founded in 1961 at the beginning of the Space Age. The author uses the occasion of the journal's 65th anniversary to present his personal retrospective on the circumstances that enabled the amazingly rapid aerospace systems developments during this time period amounting to a “conquest of space and time”. He follows this up with the prediction that a continued development of the global air transportation and of the space exploration systems will critically depend on the “conquest of the energy barrier”. He argues that there is an urgent need for a global Apollo Energy Project.</div></div>","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"160 ","pages":"Article 101174"},"PeriodicalIF":16.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145823752","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Technology exploration of zero-emission regional aircraft: Why, what, when and how?","authors":"Evangelia Pontika , Panagiotis Laskaridis , Phillip J. Ansell , Kiruba Haran , Rukshan Navaratne , Timoleon Kipouros","doi":"10.1016/j.paerosci.2025.101171","DOIUrl":"10.1016/j.paerosci.2025.101171","url":null,"abstract":"<div><div>The paper focuses on the exploration and comparison of zero-emission technology strategies for regional aircraft. While significant progress is made on the development of technologies, systems and aircraft configurations, major challenges and uncertainties mean that various strategies are considered but are difficult to compare as they rely on different technologies, metrics, requirements, maturity levels and sustainability targets. A novel, holistic approach that captures inter-dependencies, synergies and combined impact of technologies is developed to evaluate the feasibility of such aircraft over 2 horizons, quantify performance and emissions through various phases of the life cycle, establish technology bottlenecks and required step changes and classify developments in terms of impact and risk. For at least 30 passengers at 300 nmi, significant advances are required for fuel cells (2 kW/kg), electric machines (13 kW/kg), power distribution (<span><math><mo>></mo></math></span>1.5 kVolts), and thermal management systems (3.5 kW/kg and 3.5 kW/kW). These will lead to major mission level (<span><math><mo>+</mo></math></span>90%) and lifecycle energy penalties (up to <span><math><mo>+</mo></math></span>177%) with a carbon intensity level of 6.5 kg<sub>CO2</sub>/kg<sub>H2</sub> (ex. blue, turquoise, green hydrogen) required to breakeven current CO<sub>2</sub> levels. Step changes including superconductivity and high temperature fuel cells, along with aircraft mass and drag reductions are required to increase capacity to <span><math><mrow><mi>pax</mi><mo>></mo><mn>40</mn></mrow></math></span> and 800 nmi, and achieve energy reductions against existing designs. The energy density of batteries and the need of gas turbines to meet diversion and hold requirements limit full electric variants to 30 passengers at 200 nmi with 480 Wh/kg battery energy density but they can offer an exceptional energy per passenger benefit (<span><math><mo>∼</mo></math></span>40% reduction) against current aircraft.</div></div>","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"160 ","pages":"Article 101171"},"PeriodicalIF":16.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146001044","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"65th anniversary of progress in aerospace sciences","authors":"Max F. Platzer","doi":"10.1016/j.paerosci.2026.101175","DOIUrl":"10.1016/j.paerosci.2026.101175","url":null,"abstract":"","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"160 ","pages":"Article 101175"},"PeriodicalIF":16.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"146047960","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Joshua Bird , Zhanan Ao , Adam C. Frey , Nathan Sell , Andrew Plummer , Joseph S.A. Dawe , Oliver J. Pountney , Nouf Sameh , Siniša Djurović , Matteo F. Iacchetti , Alexander C. Smith , Carl M. Sangan
{"title":"Cryogenic pumping of liquid hydrogen for aerospace propulsion","authors":"Joshua Bird , Zhanan Ao , Adam C. Frey , Nathan Sell , Andrew Plummer , Joseph S.A. Dawe , Oliver J. Pountney , Nouf Sameh , Siniša Djurović , Matteo F. Iacchetti , Alexander C. Smith , Carl M. Sangan","doi":"10.1016/j.paerosci.2025.101155","DOIUrl":"10.1016/j.paerosci.2025.101155","url":null,"abstract":"<div><div>Hydrogen fuelled propulsion systems are key to enabling sustainable flight. Efficient conveyance of the hydrogen from the storage tank to the propulsor is critical when realising a successful system. Different propulsion architectures that can be powered with hydrogen include Proton Exchange Membrane Fuel Cells, Hydrogen-Electric hybrid power trains, and Hydrogen combustors. Regardless of the propulsion technology, the hydrogen will likely be stored as a liquid (LH<sub>2</sub>) and pumped accordingly. The most suitable pump system required to distribute the LH<sub>2</sub> will be dependent on the delivery requirements for the propulsor and the aircraft mission.</div><div>This review identifies the state-of-the art in pumping cryogenic fluids, specifically LH<sub>2</sub>. Pumping LH<sub>2</sub> presents a significant engineering challenge when considering the low viscosity, small molecule size, and low boiling point of hydrogen. The review is considered regarding three Case Study missions of different aircraft operating with different requirements: urban air mobility, regional propeller aircraft, and long-haul hydrogen combustion. These Case Studies have been modelled under different operational conditions to derive different pump specifications. The three operational ranges required have then been used to develop initial sizes of given pump architectures. This pump sizing was then critiqued using Figures of Merit (FoM) for pump down selection based on initial design calculations. Following a weighted down selection process, pump architectures for the three Case Studies were recommended. Further consideration was given to the electrical motor coupling and drive mechanism for the fluid-mechanical components. Finally, remaining gaps in the literature are identified which must be investigated in order for long-term solutions for LH<sub>2</sub> pumping technologies to be developed.</div></div>","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"160 ","pages":"Article 101155"},"PeriodicalIF":16.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145611950","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Advancing aviation sustainability by 2050: Scaling renewable energy systems for hydrogen production and E-fuel integration","authors":"Mahdi Jahami , Paramvir Singh , Bhupendra Khandelwal","doi":"10.1016/j.paerosci.2025.101170","DOIUrl":"10.1016/j.paerosci.2025.101170","url":null,"abstract":"<div><div>Sustainable Aviation Fuels (SAFs) and e-fuels present a transformative opportunity to significantly decarbonize aviation. However, their widespread adoption depends on overcoming challenges such as production scalability, infrastructure expansion, and cost efficiency. This study explores the potential of integrating e-fuels into aviation by evaluating three scenarios: Scenario 0 (99 % conventional jet fuel), Scenario 1 (50 % e-fuels blend), and Scenario 2 (100 % e-fuels). Using SARIMAX modeling, we project aviation fuel demand to reach 182.4 billion gallons by 2050. Under Scenario 0, this results in 195.3 million metric tonnes (MMT) of CO<sub>2</sub> emissions. Scenario 1 achieves a 50 % reduction to 97.7 MMT, while Scenario 2 nearly eliminates emissions, reducing them by 96 % to 2.8 MMT. To meet fuel demand, Scenario 1 requires 223 MMT of hydrogen per year and approximately 8000 Concentrated Solar Towers (CST), whereas Scenario 2 doubles these needs to 446.5 MMT of hydrogen and 16,000 CST systems. Scenario 1 provides a pragmatic near-term approach by leveraging existing infrastructure, while Scenario 2 represents a long-term, near-zero emissions pathway. This analysis highlights the essential role of green hydrogen and renewable energy systems in aviation decarbonization. Accelerated investments, policy enhancements, and technological innovations are crucial to bridging the gap between ambition and implementation, ensuring a sustainable future for air travel.</div></div>","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"160 ","pages":"Article 101170"},"PeriodicalIF":16.2,"publicationDate":"2026-01-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145753298","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
{"title":"Advances in early warning and active control of compressor instabilities for aerospace applications","authors":"Yang Liu , Juan Du , Dan Zhao","doi":"10.1016/j.paerosci.2025.101156","DOIUrl":"10.1016/j.paerosci.2025.101156","url":null,"abstract":"<div><div>This paper provides a comprehensive overview of the methods developed over the past 40 years for predicting stall and surge in gas turbine and aero-engine compressors. The review encompasses theoretical models, real-time signal analysis techniques for early stall and surge warning, and their integration into active control systems. For circumferentially propagating rotating stall, the Moore-Greitzer model and harmonic analysis of dynamic signals laid the foundation for predicting stall and enabling active control strategies. The discovery of two types of stall precursors and the recognition that stall typically precedes surge led to the development of early warning methods based on stall precursor detection, such as spatial Fourier transform and traveling wave energy analysis. A deeper understanding of stall mechanisms has revealed the unsteady behavior of tip leakage vortices as an earlier precursor disturbance. Concurrently, numerous stall warning techniques—including correlation analysis, wavelet analysis, modal decomposition, and deep learning—have been developed to improve the timeliness and reliability of warnings. The robustness of these methods under various operational factors, such as inlet distortion, tip clearance size, and rotor eccentricity, has been thoroughly analyzed, supporting their integration with active control strategies. In contrast, surge early warning remains more challenging due to the limited understanding of the surge-inducing mechanisms in axial fluctuations; current detection primarily relies on frequency monitoring of pressure, vibration, and acoustic signals. As modern engines operate under increasingly complex inlet conditions and higher load demands, the routes to instability and the nature of precursor disturbances have diversified. This presents significant challenges in developing early warning methods that comprehensively address the various instability pathways. The paper highlights the most influential contributions in this field and discusses prospects for future research directions.</div></div>","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"159 ","pages":"Article 101156"},"PeriodicalIF":16.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145528308","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Lei Huang, Yinghui Zuo, Cong Guo, Bo Wang, Kuo Tian
{"title":"Machine learning in flight parameter-based structural load prediction: A review and framework proposal","authors":"Lei Huang, Yinghui Zuo, Cong Guo, Bo Wang, Kuo Tian","doi":"10.1016/j.paerosci.2025.101145","DOIUrl":"10.1016/j.paerosci.2025.101145","url":null,"abstract":"<div><div>Flight Parameter-based Structural Load Prediction (FP-SLP) is a key technology for Structural Health Monitoring (SHM) and remaining life estimation of in-service aircraft and flight vehicles. With the continuous development of Machine Learning (ML), FP-SLP has gained powerful assistance. However, in engineering application of FP-SLP, ML technology faces bottlenecks such as fragmentation and data scarcity, which severely constrain its further development and application. This paper aims to conduct a systematic review of ML research and applications in FP-SLP related fields, establish a new advanced technical framework and explore future development directions, so as to provide references for theoretical research and engineering practice. In this paper, we first clarify the fundamental concepts of FP-SLP and describe the general workflow from data acquisition, surrogate modeling to online prediction, and comprehensively analyze existing challenges in engineering practice. Subsequently, a systematic review of ML applications of in FP-SLP is presented, concentrating on four core problems: efficient flight data preprocessing, high-precision surrogate modeling, model tuning and validation, and model deployment and maintenance. The advantages and effectiveness of advanced ML techniques in overcoming the existing challenges in FP-SLP are demonstrated. Based on various state-of-the-art ML techniques, this paper proposes a new advanced framework for FP-SLP, which provides a paradigm for subsequent research and engineering applications. Meanwhile, an original industrial-grade dataset, Aircraft structural Load Benchmark dataset (AirLoadBench), derived from real flight testing, is constructed and made public for the comparative research needs in the FP-SLP field. Finally, the AirLoadBench dataset is applied to evaluate various ML models in terms of prediction accuracy and training time. The results show that XGBoost model and XGBoost-based Ensemble learning (XGBoost-Ens) model demonstrates significant advantages among numerous models, outperforming others in both prediction accuracy and training efficiency.</div></div>","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"159 ","pages":"Article 101145"},"PeriodicalIF":16.2,"publicationDate":"2025-11-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145289884","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}
Gabriele Capasso , Christian Gogu , Julien Baroth , Jean-Philippe Navarro , Martin Kempeneers
{"title":"Comparative review of probabilistic frameworks for structural integrity in aeronautical and civil engineering design codes","authors":"Gabriele Capasso , Christian Gogu , Julien Baroth , Jean-Philippe Navarro , Martin Kempeneers","doi":"10.1016/j.paerosci.2025.101141","DOIUrl":"10.1016/j.paerosci.2025.101141","url":null,"abstract":"<div><div>In structural engineering, uncertainties arising from various sources, such as variability in material properties, loading conditions, manufacturing discrepancies and model inaccuracies, can significantly impact the integrity and performance of structures. This paper presents a comprehensive review of probabilistic and semi-probabilistic frameworks used to address these uncertainties in the context of static strength assessment within the aeronautical and civil engineering domains. By comparing the approaches used in aeronautical engineering, specifically for large commercial aircraft, with those in civil engineering, this paper aims to identify best practices and assess their transferability between the two fields. The review covers legislative and certification requirements, structural testing, reliability assessment approaches as well as the determination and use of safety factors. Through this comparative analysis, the paper seeks to highlight the differences and similarities in managing uncertainties and ensuring structural integrity, ultimately providing insights that could enhance design practices in both domains.</div></div>","PeriodicalId":54553,"journal":{"name":"Progress in Aerospace Sciences","volume":"158 ","pages":"Article 101141"},"PeriodicalIF":16.2,"publicationDate":"2025-10-01","publicationTypes":"Journal Article","fieldsOfStudy":null,"isOpenAccess":false,"openAccessPdf":"","citationCount":null,"resultStr":null,"platform":"Semanticscholar","paperid":"145160333","PeriodicalName":null,"FirstCategoryId":null,"ListUrlMain":null,"RegionNum":1,"RegionCategory":"工程技术","ArticlePicture":[],"TitleCN":null,"AbstractTextCN":null,"PMCID":"","EPubDate":null,"PubModel":null,"JCR":null,"JCRName":null,"Score":null,"Total":0}