Search Results (64)

As an energy-intensive industry, the aviation sector’s carbon emissions have drawn significant attention. Against the backdrop of the “dual carbon” goals, how to enhance the carbon emission efficiency of airlines has become an urgent issue to be addressed for both industry development and low-carbon targets. This paper constructs an evaluation system for the carbon emission efficiency of airlines and uses the SBM-DDF model under the global production possibility set, combined with the bootstrap-DEA method, to calculate the efficiency values. On this basis, the fuzzy-set qualitative comparative analysis method is employed to analyze the synergistic effects of multiple influencing factors in three dimensions: economic benefits, transportation benefits, and energy consumption on improving carbon emission efficiency. The research findings reveal that, first, a single influencing factor does not constitute a necessary condition for achieving high carbon emission efficiency; second, there are four combinations that enhance carbon emission efficiency: “load volume-driven type”, “scale revenue-driven type”, “high ticket price + technology-driven type”, and “passenger and cargo synergy mixed type”. These discoveries are of great significance for promoting the construction of a carbon emission efficiency system by Chinese airlines and achieving high-quality development in the aviation industry. Full article

Addressing the urgent need to decarbonise aviation and valorise agricultural waste, this paper investigates the production of Sustainable Aviation Fuel (SAF) from corn stover. A preliminary evaluation based on a literature review indicates that among various conversion technologies, fast pyrolysis (FP) emerged as the most promising option, offering the highest fuel yield (22.5%) among various pathways, a competitive potential minimum fuel selling price (MFSP) of 1.78 USD/L, and significant greenhouse gas savings of up to 76%. Leveraging Aspen Plus simulation, SAF production via FP was rigorously designed and optimised, focusing on the heat integration strategy within the process to minimise utility consumption and ultimately the total cost. Consequently, the produced fuel exceeded the American Society for Testing and Materials (ASTM) limit for the final boiling point, rendering it unsuitable as a standalone jet fuel. Nevertheless, it achieves regulatory compliance when blended at a rate of up to 10% with conventional jet fuel, marking a practical route for early adoption. Energy optimisation through pinch analysis integrated four hot–cold stream pairs, eliminating external heating, reducing cooling needs by 55%, and improving sustainability and efficiency. Economic analysis revealed that while heat integration slashed utility costs by 84%, the MFSP only decreased slightly from 2.35 USD/L to 2.29 USD/L due to unchanging material costs. Sensitivity analysis confirmed that hydrogen, catalyst, and feedstock pricing are the most influential variables, suggesting targeted reductions could push the MFSP below 2 USD/L. In summary, this work underscores the technical and economic viability of corn stover-derived SAF, providing a promising pathway for sustainable aviation and waste valorisation. While current limitations restrict fuel quality during full substitution, the results affirm the feasibility of SAF blending and present a scalable, low-carbon pathway for future development. Full article

To address the issue of low accuracy and stability in traditional Convolutional Neural Networks (CNN)-based defect depth prediction for civil aircraft composites, we propose an improved Feature Enhancement Network (FEN)-CNN-Bidirectional Long Short-Term Memory (BiLSTM) impact damage depth prediction method. By integrating terahertz (THz) time-domain, frequency-domain, and absorbance spectroscopy with Confocal Laser Scanning Microscopy (CLSM) depth measurements, the correlation between THz spectral features and impact damage defect depth is systematically elucidated, thereby constructing a “THz features-depth” dataset. Furthermore, by leveraging the FEN model’s feature enhancement and denoising capabilities, along with the BiLSTM model’s bidirectional sequence modeling capability, the underlying relationship between terahertz spectral features and defect depth is deeply learned. This approach improves the stability and accuracy of spectral feature extraction by the CNN model under complex conditions. Ablation experiments revealed the improved model, compared to traditional CNN, reduced Mean Absolute Error (MAE), Mean Absolute Percentage Error (MAPE), Mean Squared Error (MSE), and Root Mean Squared Error (RMSE) by 43.08%, 44.4%, 57.18%, and 34.56%, respectively. Additionally, it decreased the Relative Standard Deviation (RSD) by 32.14%, and increased the Coefficient of Determination (R²) by 6.8%. Comparative experiments demonstrated the proposed model achieved an MSE of 0.0075 and an R² of 0.9539, outperforming other models. This study provides a novel method for precise low-velocity impact damage assessment in carbon fiber reinforced composites, enhancing safety evaluation for civil aircraft composite structures and contributing to aviation safety. Full article

Electric ducted fans are gaining prominence in aviation due to their compact size, low noise, and zero emissions compared to conventional gas turbines. This study presents an experimental test system for a 390 mm electric Ducted Propulsion Fan developed by the Aerospace Propulsion Systems group at Hanoi University of Science and Technology. The carbon fiber composite thruster, driven by a centrally located BLDC motor, was mounted on a test stand equipped with force and rotational speed (rpm) sensors. Power was supplied through two battery configurations, eight-pack and nine-pack, with voltage and current monitored and controlled via an ESC module. Experiments conducted from 2000 to 7000 rpm explored the relationship between electrical inputs and aero-propulsive outputs. The results revealed that input power, current, and sound pressure level (SPL) amplified meaningfully with rpm, while the voltage slightly declined. The maximum rpm reached 6500 rpm for the eight-pack and 7000 rpm for the nine-pack configurations. When greater than 6000 rpm, the SPL reaches close to 120 dB. The eight-pack configuration provided higher thrust per volt, whereas the nine-pack offered better thrust per ampere and improved starting power. Although dimensionless indices, including power coefficient (CP), thrust coefficient (CT), and figure of merit (FM), reduced with rpm, the FM remained between 0.7 and 0.75 at medium speeds, demonstrating effective energy conversion. Full article

Flywheel energy storage systems (FESSs) can reach much higher speeds with the development of technology. This is possible with the development of composite materials. In this context, a study is being carried out to increase the performance of the FESS, which is especially used in leading fields, such as electric power grids, the military, aviation, space and automotive. In this study, a flywheel design and analysis with a hybrid (multi-layered) rotor structure are carried out for situations, where the cost and weight are desired to be kept low despite high-speed requirements. The performance values of solid steel, solid titanium, and solid carbon composite flywheels are compared with flywheels made of different thicknesses of carbon composite on steel and different thicknesses of carbon composite materials on titanium. This study reveals that wrapping carbon composite material around metal in varying thicknesses led to an increase of approximately 10–46% in the maximum rotational velocity of the flywheel. Consequently, despite a 33–42% reduction in system mass and constant system volume, the stored energy was enhanced by 10–23%. It was determined that the energy density of the carbon-layered FESS increased by 100% for the steel core and by 65% for the titanium core. Full article

In actual flight, aircraft rarely operate under a single design condition; multiple flight states must be considered to meet performance requirements. With the push for green and low-carbon aviation, there is growing demand for high-performance, fuel-efficient aircraft. This study focuses on the Blended Wing Body (BWB) configuration. To address large-scale design variables and multiple constraints, a discrete adjoint-based aerodynamic optimization method is developed, improving computational efficiency and reducing cost.The optimization results show reduced drag coefficients across various flight conditions and enhanced drag divergence performance. The robustness of the multi-point optimization approach is validated, confirming its ability to improve aircraft performance across different states. The proposed method is practical and provides an effective reference for aerodynamic design of BWB aircraft. Full article

The aviation sector is a significant contributor to greenhouse gas emissions, and with the increasing demand for air travel these emissions are projected to continue rising in the coming years. Sustainable Aviation Fuel (SAF) could greatly help reduce these emissions and make the aviation industry more eco-friendly. SAF is a renewable, low-carbon alternative to conventional jet fuel produced from sustainable resources. A key step to bringing the fuel into regular use is studying how people view it. Understanding what the public think and feel about biofuels, including aviation fuel, is very important. This is because public opinion can shape consumer interest, demand for products, and the willingness of governments to back green energy policies and invest in clean technologies. The study systematically evaluates the public opinion, perception and awareness of SAF in the South Central United States and its utilization to decarbonize the aviation industry. This is performed through a series of multiple-choice survey questions and interviews. The study results show that while there is some recognition of the environmental impact of aviation and the potential role of biofuels in reducing this impact, there is still a need for greater public education and awareness regarding alternative fuels and their benefits for sustainable aviation. The findings of the study underscore a pivotal challenge in addressing aviation-related carbon emissions: the gap in public knowledge about potential solutions like biofuels and SAF. This gap not only reflects a lack of awareness but also hints at the possible skepticism or uncertainty among the public regarding the effectiveness and viability of these alternatives. Full article

Hybrid aircraft offer a logical pathway to reducing aviation’s carbon footprint. The thermal management system (TMS) is often neglected in the assessment of hybrid aircraft performance despite it being of major importance. After presenting the TMS architecture, this study performs a sensitivity analysis on several parameters of a retrofitted hybrid fuel cell aircraft’s performance considering three hierarchical levels: the aircraft, fuel cell system, and TMS component levels. The objective is to minimize CO₂ emissions while maintaining performance standards. At the aircraft level, cruise speed, fuel cell power, and ISA temperature were varied to assess their impact. Lowering cruise speeds can decrease emissions by up to $49\%$, and increasing fuel cell power from 200 kW to 400 kW cuts emissions by $18\%$. Higher ambient air temperatures also significantly impact cooling demands. As for the fuel cell, lowering the stack temperature from 80 °C to 60 °C increases the required cooling air mass flow by $49\%$ and TMS drag by $40\%$. At the TMS component level, different coolants and HEX offset-fin geometries reveal low-to-moderate effects on emissions and payload. Overall, despite some design choice improvements, the conventional aircraft is still able to achieve lower CO₂ emissions per unit payload. Full article

Reducing emissions in the aviation industry remains a critical challenge for global low-carbon transition. Accurate fuel consumption prediction is essential to achieving emission reduction targets and advancing sustainable development in aviation. Aircraft fuel consumption is influenced by numerous complex factors during flight, resulting in significant nonlinear relationships between segment-specific variables and fuel usage. Traditional statistical and econometric models struggle to capture these relationships effectively. This article first focuses on the different characteristics of QAR data and uses the Adaptive Noise Ensemble Empirical Mode Decomposition (CEEMDAN) method to obtain more significant potential features of QAR data, solving the problems of mode aliasing and uneven mode gaps that may occur in traditional decomposition methods when processing non-stationary signals. Secondly, a dynamic multidimensional particle swarm optimization algorithm (DMPSO) was constructed using an adaptive adjustment dynamic change method of inertia weight and learning factor, which solved the problem of local extremum and low search accuracy in the solution space that PSO algorithm is prone to during the optimization process. Then, a DMPSO-LSTM aircraft fuel consumption model was established to achieve fuel consumption prediction for three flight segments: climb, cruise, and descent. The final proposed model was validated on real-world datasets, and the results showed that it outperformed other baseline models such as BP, RNN, PSO-LSTM, etc. Among the results, the climbing segment MAE index decreased by more than 40%, the RMSE index decreased by more than 38%, and the R² index increased by more than 6%, respectively. The MAE index of the cruise segment decreased by more than 40%, the RMSE index decreased by more than 40%, and the R² index increased by more than 5%, respectively. The MAE index of the descending segment decreased by more than 20%, the RMSE index decreased by more than 30%, and the R² index increased by more than 5%, respectively. The improved prediction accuracy can be used to implement multi-criteria optimization in flight operations: (1) by quantifying weight–fuel relationships, it supports payload–fuel tradeoff decisions; (2) enhanced phase-specific predictions allow optimized climb/cruise profile selections, balancing time and fuel use; and (3) precise consumption estimates facilitate optimal fuel-loading decisions, minimizing safety margins. The high-precision fuel consumption prediction framework proposed in this study provides actionable insights for airlines to optimize flight operations and design low-carbon route strategies, thereby accelerating the aviation industry’s transition toward net-zero emissions. Full article

Against the dual-carbon background, civil aviation is in urgent need of low-carbon and green transformation. Carbon emissions from airports are one of the main environmental concerns in civil aviation, so the early realization of airport carbon peak and carbon neutrality will help accelerate the construction of green civil aviation and assist in the low-carbon transformation and upgrading of civil aviation. According to research, the terminal building, aircraft, and ramp area are the main sources of airport carbon emissions. Taking Harbin Taiping International Airport as an example, this study first measured the carbon emissions from the terminal building and ramp area of the airport in the past five years by using the emission factor method; then, we measured the carbon emissions from aircraft in the airport in the past five years by using the ICAO method and finally predicted the trend of carbon emissions from aircraft and the possibility of reaching the peak carbon emissions of the airport in the coming years by using scenario analysis and the Monte Carlo simulation method. The results show that the total carbon emissions of Harbin Taiping International Airport will be 458,800 tonnes in 2023 and up to 581,100 tonnes in 2035; under the scenarios of green development and technological innovation, the airport’s carbon emissions can reach their peak by 2035, which will be lower and reached earlier under the scenario of technological innovation; the airport can improve energy use efficiency, increase the utilization of renewable energy sources, establish a carbon emission monitoring system, and actively participate in the market for carbon emission monitoring systems. Airports can systematically build a development path for airport carbon peaking by improving energy efficiency, increasing the utilization rate of renewable energy, establishing a carbon emission monitoring system, actively participating in carbon trading in the market, etc., so as to reduce carbon emissions from airports and promote the transformation and upgrading of civil aviation into a green and low-carbon sector. Full article

Hybrid propulsion systems have become a focal point of low-carbon aviation research due to their advantages in energy savings, emissions reduction, and noise abatement. This study develops an integrated design methodology for hybrid propulsion systems for aircraft, incorporating multidisciplinary algorithms to establish an overall performance model. Building on this model, a comprehensive aircraft design platform was constructed, and its simulation capabilities were validated. Focusing on the mission requirements of a 180-seat narrow-body airliner, this study analyzed and compared the characteristics of three hybrid propulsion architectures, optimized their design schemes, and evaluated the key technologies for each architecture. A sensitivity analysis was conducted for critical technologies within the turboelectric architecture. The results indicate that, based on current data and future projections, a turboelectric system featuring batteries with a specific energy of 500 Wh/kg and installed motor power of 3 MW demonstrates superior performance, reduced fuel consumption, and no additional energy storage burden, making it the preferred propulsion solution. Furthermore, enhancing the utilization of aft-mounted fans and increasing the power blending coefficient can improve system performance. However, the maximum power blending coefficient is constrained to 27.25% by the specific motor power capacity. Full article

Liquid hydrogen has the potential to significantly reduce in-flight carbon emissions in the aviation industry. Among the most promising aircraft configurations for future hydrogen-powered aviation are the blended wing body and the pure flying wing configurations. However, their tapered and flattened airframe designs pose a challenge in accommodating liquid hydrogen storage tanks. This paper presents a design guide to tapered conformable pressure tanks for liquid hydrogen storage. The proposed tank configurations feature a multi-bubble layout and are subject to low internal differential pressure. The objective is to provide tank designers with simple geometric rules and practical guidelines to simplify the design process of tapered multi-bubble pressure tanks. Various tank configurations are discussed, starting with a simple tapered two-bubble tank and advancing to more complex tapered configurations with a multi-segment and multi-bubble layout. A comprehensive design methodology is established, providing tank designers with a step-by-step design procedure and highlighting the practical guidelines in each step of the design process. Full article

With the rapid growth of air travel, reducing carbon emissions in aviation is imperative. Electric aircraft play a key role in achieving sustainable aviation, especially for large civil aircraft, where reducing emissions, improving the fuel efficiency, and enabling flexible power regulation are essential. This study proposes a dual-shaft, separated-exhaust fuel cell hybrid aircraft propulsion system (HAPS), using a solid oxide fuel cell (SOFC) to replace the conventional turbine-driven compressor. The independent speed control of the high- and low-pressure spools is realized via a power distribution system. A thermodynamic model is developed, and performance evaluations, including parametric, exergy, and sensitivity analyses, are conducted. At the design point, the system delivers 36.304 kN thrust, 16.775 g/(kN·s) specific fuel consumption, 15.931 MW SOFC power, and 54.759% SOFC efficiency. The exergy analysis highlights the optimization of components like the heat exchanger and fan to reduce energy losses. The sensitivity analysis reveals that the spool speeds and fuel utilization significantly impact the performance. The findings provide valuable insights into optimizing control strategies and offer a novel, efficient, and low-carbon power solution for aviation, supporting the industry’s transition towards sustainability. Full article

As the civil aviation market is in a state of continuous growth, the architecture of passenger airport terminals needs to follow the industry’s constant development. The objective of this research is to investigate the current state of terminals in Poland in relation to the aspects of representativeness and low-tech sustainability solutions incorporated into design strategies. The conducted study is a critical review of existing literature followed by a case study of relevant examples of airport terminals, from an architectural perspective. The main findings show that seemingly contradicting principles can co-exist in particular spectra of design. The broadly used big shed design method, which provides terminal buildings with an adequate level of prominence, can also facilitate sustainable solutions, especially in the areas of user comfort, energy efficiency and life cycle assessment, i.e., buildings are easily adaptable, what is demanded by constantly evolving operational models and increasing airport terminal capacities. As further improvements are definitely needed to answer the increasing demand for a reduction in the carbon footprint of buildings, changes are desirable and should focus on establishing an adequate balance between a sustainable approach and the urge to create representative, state-of-the art terminal buildings. Full article

In the last few decades, the problem of pollution resulting from human activities has pushed research toward zero or net-zero carbon solutions for transportation. The main objective of this paper is to perform a preliminary performance assessment of the use of hydrogen in conventional turbine engines for aeronautical applications. A 0-D dynamic model of the Allison 250 C-18 turboshaft engine was designed and validated using conventional aviation fuel (kerosene Jet A-1). A dedicated, experimental campaign covering the whole engine operating range was conducted to obtain the thermodynamic data for the main engine components: the compressor, lateral ducts, combustion chamber, high- and low-pressure turbines, and exhaust nozzle. A theoretical chemical combustion model based on the NASA-CEA database was used to account for the energy conversion process in the combustor and to obtain quantitative feedback from the model in terms of fuel consumption. Once the engine and the turbomachinery of the engine were characterized, the work focused on designing a 0-D dynamic engine model based on the engine’s characteristics and the experimental data using the MATLAB/Simulink environment, which is capable of replicating the real engine behavior. Then, the 0-D dynamic model was validated by the acquired data and used to predict the engine’s performance with a different throttle profile (close to realistic request profiles during flight). Finally, the 0-D dynamic engine model was used to predict the performance of the engine using hydrogen as the input of the theoretical combustion model. The outputs of simulations running conventional kerosene Jet A-1 and hydrogen using different throttle profiles were compared, showing up to a 64% reduction in fuel mass flow rate and a 3% increase in thermal efficiency using hydrogen in flight-like conditions. The results confirm the potential of hydrogen as a suitable alternative fuel for small turbine engines and aircraft. Full article