Search Results (40)

One of the challenges of our age is climate change and the ways in which it affects the Earth’s global ecosystem. To face the problems linked to such an issue, the international community has defined actions aimed at the reduction in greenhouse gas emissions in several sectors, including the aviation industry, which has been requested to mitigate its environmental impact. Conventional aircraft propulsion systems depend on fossil fuels, significantly contributing to global carbon emissions. For this reason, innovative propulsion technologies are needed to reduce aviation’s impact on the environment. Electric propulsion has emerged as a promising solution among the several innovative technologies introduced to face climate change challenges. It offers, in fact, a pathway to more sustainable air travel by eliminating direct greenhouse gas emissions, enhancing energy efficiency. Unfortunately, integrating electric motors into aircraft is currently a big challenge, primarily due to thermal management-related issues. Efficient heat dissipation is crucial to maintain optimal performance, reliability, and safety of the electric motor, but aeronautic applications are highly demanding in terms of power, so ad hoc Thermal Management Systems (TMSs) must be developed. The present paper explores the design and optimization of a TMS tailored for a megawatt electric motor in aviation, suitable for regional aircraft (~80 pax). The proposed system relies on coolant oil injected through a hollow shaft and radial tubes to directly reach hot spots and ensure effective heat distribution inside the permanent magnet cavity. The goal of this paper is to demonstrate how advanced TMS strategies can enhance operational efficiency and extend the lifespan of electric motors for aeronautic applications. The effectiveness of the radial tube configuration is assessed by means of advanced Computational Fluid Dynamics (CFD) analysis with the aim of verifying that the proposed design is able to maintain system thermal stability and prevent its overheating. Full article

Technological innovation toward electrification and digitalization is revolutionizing aviation, paving the way for new aeronautical paradigms and novel modes to transport goods and people in urban and regional environments. Advanced Air Mobility (AAM) leverages vertical and digital mobility, driven by safe, quiet, sustainable, and cost-effective electric vertical takeoff and landing (VTOL) aircraft. A key enabler of this transformation is the development of vertiports—dedicated infrastructure designed for VTOL operations. Vertiports are pivotal in integrating AAM into multimodal transport networks, ensuring seamless connectivity with existing urban and regional transportation systems. Their design, placement, and operational framework are central to the success of AAM, influencing urban accessibility, safety, and public acceptance. These facilities should accommodate passenger and cargo operations, incorporating charging stations, takeoff and landing areas, and optimized traffic management systems. Public and private sectors are investing in vertiports, shaping the regulatory and technological landscape for widespread adoption. As cities prepare for the future of aerial mobility, vertiports will be the cornerstone of sustainable, efficient, and scalable air transportation. Full article

Electrification has become increasingly common in aerospace due to climate change concerns. After successful applications in general aviation aircraft, electrification is now addressing subregional (up to 19 passengers) and regional aircraft (around 80 passengers). Megawatt-class electric motors are needed both to drive propellers and to act as high-power generators in hybrid–electric propulsion systems. Power levels for this class of aircraft require a proper design of heat management systems capable of dissipating a much higher quantity of heat than that dissipated by traditional cooling systems. The technical solution here explored is based on the addition into a diathermic base liquid of nanoparticles, which can increase (by up to 30%) the thermal conductivity of the refrigerant, also providing large surface area enhancing the heat transfer capacity of base liquids. The Italian Aerospace Research Centre (CIRA), as part of the European research initiative Optimised Electric Network Architectures and Systems for More-Electric Aircraft (ORCHESTRA), developed a thermal management system (TMS) based on impinging jets technology for a 1 MW electric motor. In this work, a numerical verification of the possibility for nanofluids to improve the heat exchange efficiency of a submerged oil impinging jets TMS designed to directly cool the inner components of a 1 MW motor is conducted. Investigations aimed to analyse two nanoparticle types (alumina and graphite) added to diathermic oil with concentrations between 1% and 5% by volume. The application of nanofluids significantly increases final thermal conductivity with respect to conventional coolants, a 60% improvement in heat transfer at a fixed mass flow rate is achieved. Electric motor maximum temperatures are approximately 10% lower than those achieved with solely diathermic oil. This result is significant as a safety margin is needed in all cases where a sudden increase in power occurs. Full article

This paper examines the problem of modeling lithium–sulfur (Li-S) battery discharge dynamics. The importance of this problem stems from the attractive specific energy levels achievable by Li-S batteries, which can be particularly appealing for applications such as aviation electrification. Previous research presents different Li-S battery models, including “zero-dimensional” models that neglect diffusion while using the laws of electrochemistry to represent reduction–oxidation (redox) rates. Zero-dimensional models typically succeed in capturing key features of Li-S battery discharge, including the high plateau, low plateau, and dip point visible in the discharge curves of certain Li-S battery chemistries. However, these models’ use of one state variable to represent the mass of each active species tends to furnish high-order models, with many state variables. This increases the computational complexity of model-based estimation and optimal control. The main contribution of this paper is to develop low-order state-space model of Li-S battery discharge. Specifically, the paper starts with a seventh-order zero-dimensional model of Li-S discharge dynamics, analyzes its discharge behavior, constructs phenomenological second- and third-order models capable of replicating this behavior, and parameterizes these models. The proposed models succeed in capturing battery discharge behavior accurately over a wide range of discharge rates. To the best of our knowledge, these are two of the simplest published models capable of doing so. Full article

This research addresses the increasing electrification of aircraft systems, driven by the need to improve energy efficiency and reduce CO₂ emissions in global aviation. The transition to more-electric aircraft (MEA) is advocated as a promising strategy, as it is expected to improve environmental performance and economic viability. However, this shift significantly increases the demand for on-board electrical power. One alternative to traditional engine generators is novel power supply systems such as fuel cell systems. In order to design these systems effectively, it is essential to determine the electrical power requirements that the fuel cells must supply. Estimating the electrical power consumption of individual aircraft systems is critical given the proprietary nature of manufacturer data. Using existing literature methods, this study aims to identify the essential variables for estimating the magnitude of power consumption. The research focuses on different aircraft models, taking into account their system architectures and electrification trends, in particular for Airbus and Boeing models. The study includes a detailed description of the aircraft systems, calculation methods, and presentation and analysis of the estimated electrical power requirements. Despite a lack of available data for comparison, the calculated results appear to be reasonably consistent with existing literature and provide valuable insights into the electrical power requirements of aircraft systems. Full article

The aviation industry is undergoing electrification due to the increased global focus on reducing emissions in air traffic. Regarding the volatility of raw material prices, one main objective is the increase in the specific power of the motor. This matches the ambitious targets of the CoE project (Center of Excellence) in Finland on high-speed electric motors. The targeted specific power is 20 kW/kg. In this work, motors are designed and optimized for a fully electric regional aircraft. motors with different slot/pole configurations and rotational speed values are studied to determine the advantage of increasing speed in terms of weight reduction. As increasing speed requires the use of a gearbox, the overall weight of the motor and the gearbox is evaluated in post-processing, which allows for determining the impact of high speed on the overall weight. An optimization tool coupled with an electromagnetic and mechanical analysis is used to optimize 1 MW surface mounted permanent magnet synchronous motors (S-PMSMs) for given specifications of regional electric aircraft. Optimization results indicate that there is considerable gain in terms of overall weight only when increasing the speed to the range of 10,000–15,000 rpm. Full article

The electrification of aviation represents a significant technological frontier, promising substantial advancements in sustainable transportation. This paper presents a comprehensive set of taxonomies that systematically categorize and analyze the multifaceted aspects of electric aviation, with a particular focus on machine-related components and systems. It provides detailed classifications of electric aircraft propulsion systems, power management architectures, and energy storage technologies, offering insight into their design, functionality, and integration challenges. The paper explores the ecosystem of electric aviation, including key stakeholders, use cases, and enabling technologies, which are vital for coordinating machine development strategies and fostering sustainable growth. The creation of business models that cater to the dynamic nature of the industry, emphasizing the role of innovative machine designs in shaping market adoption are discussed in the paper. The study highlights the importance of electric aviation for regional development, outlining predictive models for regional market development that consider machine capabilities and infrastructure requirements. Full article

This work provides an extended description of the tools developed in the Wolfram Mathematica environment to characterize proton exchange membrane (PEM) fuel cells. These tools, with their user-friendly interface, facilitate the calculation of the main parameters required to obtain the PEM fuel cell polarization curve, offering a seamless and intuitive experience. Various mathematical models and algorithms are coded to accurately calculate the parameters needed for the polarization curve analysis. This study presents the development and validation of a computational tool designed to simulate the performance of proton exchange membrane (PEM) fuel cells. The tool integrates thermodynamic and electrochemical equations to predict key operational parameters, and was validated using experimental data from a commercial Ballard^® PEM fuel cell to ensure its accuracy. The validation process involved comparing the numerical predictions with empirical measurements under various operating conditions. The results demonstrate that the computational tool accurately replicates the performance characteristics observed in the experimental data, confirming its reliability and instilling confidence in its use for simulating PEM fuel cell behavior. This tool offers a valuable resource for optimizing fuel cell design and operation, providing insights into the efficiency, output, and potential areas for improvement. Future work will expand the tool’s capabilities to include degradation mechanisms and long-term performance predictions. This advancement underscores the tool’s potential as a comprehensive solution for academic research and industrial applications in fuel cell technology. Full article

Until recently, electrified aircraft propulsion (EAP) technology development has been driven by the dual objectives of reducing greenhouse gas (GHG) emissions and addressing the depletion of fossil fuels. However, the increasing severity of climate change, posing a significant threat to all life forms, has resulted in the global consensus of achieving net-zero GHG emissions by 2050. This major shift has alerted the aviation electrification industry to consider the following: What is the clear path forward for EAP technology development to support the net-zero GHG goals for large commercial transport aviation? The purpose of this paper is to answer this question. After identifying four types of GHG emissions that should be used as metrics to measure the effectiveness of each technology for GHG reduction, the paper presents three significant categories of GHG reduction efforts regarding the engine, evaluates the potential of EAP technologies within each category as well as combinations of technologies among the different categories using the identified metrics, and thus determines the path forward to support the net-zero GHG objective. Specifically, the paper underscores the need for the aviation electrification industry to adapt, adjust, and integrate its EAP technology development into the emerging new engine classes. These innovations and collaborations are crucial to accelerate net-zero GHG efforts effectively. Full article

Electrifying aircraft, a crucial advancement in the aviation industry, aims to cut pollutive emissions and boost energy efficiency. Traditional aircraft depend on fossil fuels, which contribute significantly to greenhouse gas emissions and environmental pollution. Despite progress in electric propulsion and energy storage technologies, challenges such as low energy density and integration issues persist. This paper provides a comprehensive thematic and bibliometric analysis to map the research landscape in aircraft electrification, identifying key research themes, influential contributors, and emerging trends. This study applies natural language processing to unstructured bibliographic data and cross-sectional statistical methods to analyze publications, citations, and keyword distributions across various categories related to aircraft electrification. The findings reveal significant growth in research output, particularly in energy management and multidisciplinary design analysis. Collaborative networks highlight key international partnerships, with the United States and China being key research hubs, while citation metrics highlight the impact of leading researchers and institutions in these countries. This study provides valuable insights for researchers, policymakers, and industry stakeholders, guiding future research directions and collaborations. Full article

The aviation sector makes up 11% of all transportation emissions and is considered a “hard to abate” sector since, due to the long distances to be traveled, opportunities for electrification are rather limited. Therefore, since there are no alternatives to fuels, Sustainable Aviation Fuels (SAFs), or fuels produced from biomass, have recently been developed to reduce climate-changing emissions in the aviation sector. Using Life Cycle Assessment, this research evaluated the environmental compatibility of different SAF production routes from seven biomasses: four food feedstocks (Soybean, Palm, Rapeseed, and Camelina), one non-food feedstock (Jatropha curcas L.), and two wastes (Waste Cooking Oil, or WCO, and Tallow). The evaluation was carried out using SimaPro 9.5 software. The results showed that the two potentially most favorable options could be Camelina and Palma, as they show minimal environmental impacts in 4 and 7 out of 18 impact categories, respectively. Soybean, on the other hand, appears to be the least sustainable precursor. Considering GWP, SAF production could reduce the values compared to fossil fuel by 2.8–3.6 times (WCO), 1.27–1.66 times (Tallow), 4.6–5.8 times (Palm), 3.4–4.3 times (Jatropha), 1.05–1.32 times (Rapeseed), and 4.36–5.5 times (Camelina), demonstrating the good environmental impact of these pathways. Finally, the sensitivity analysis showed that SAF production from waste could be an environmentally friendly option, with rather low environmental impacts, in the range of 5.13 g CO₂ eq/MJ for Tallow and 3.12 g CO₂ eq/MJ for WCO. However, some of the energy would have to come from sustainable energy carriers such as biomethane and renewable sources such as photovoltaic energy. Full article

Electrification of aircraft is a very challenging task as the demand for energy and power is high. While the storage and generation of electrical energy are widely studied due to the limited specific energy and specific power of batteries and fuel cells, electric machines (power electronics and motors) which have years of experience in many industrial fields must be improved when applied to aviation: they generally have a high efficiency but the increase in power levels determines significant thermal loads which, unlike internal combustion engines (ICE), cannot be rejected with the exhaust. There is therefore a need for thermal management systems (TMSs) with the main objective of maintaining operating temperatures below the maximum level required by electric machines. Turboprop aircraft, such as the ATR 72 or the Dash 8-Q400, are commonly used for regional transport and are equipped with two gas turbine engines whose combined power is in the order of 4 MW. Electric and hybrid propulsion systems for these aircraft are being studied by several leading commercial aviation industries and start-ups, and the 1MW motor size seems to be the main option as it could be used in different aircraft configurations, particularly those that exploit distributed electric propulsion. With reference to the topics mentioned above, the present work presents the design of a TMS for a high-power motor/generator whose electrical architecture is known. Once integrated with the electrical part, the TMS must allow a weight/power ratio of 14 kW/kg (or 20 kW/kg at peak power) while maintaining the temperature below the limit temperature with reasonable safety margins. Submerged jet oil is the cooling technique here applied with a focus on diathermic oil. Parameters affecting cooling, like rotor speed and filling factor, are analysed with advanced CFD. Full article

To further increase efficiency and to significantly reduce climate impact in the aviation sector, new propulsion concepts must be developed. As full electrification in mid- and long-range aviation is impractical due to the low gravimetric energy density of batteries, new approaches must be developed. Therefore, the so-called hybrid electric ground demonstrator (HeBo), equipped with a Rolls Royce M250-C20B gas turbine is set up. The test rig serves as a development platform for various new gas turbine-based propulsion concepts for aviation, such as hybrid electric concepts or a novel cycle concept with steam injection to the combustor, which are described in this paper. The main focus of the work is on the experimental setup and the commissioning of the baseline test rig. This will place the test rig in the context of current research activities and serve as reference for subsequent research results. Full article

Currently, great emphasis is being placed on the electrification of means of transportation, including aviation. The use of electric motors reduces operating and maintenance costs. Electric motors are subjected to various types of damage during operation, of which rolling bearing defects are statistically the most common. This article focuses on presenting a diagnostic tool for bearing conditions based on mechanic vibration signals using convolutional neural networks (CNN). This article presents an alternative to the well-known classical diagnostic tools based on advanced signal processing methods such as the short-time Fourier transform, the Hilbert–Huang transform, etc. The approach described in the article provides fault detection and classification in less than 0.03 s. The proposed structures achieved a classification accuracy of 99.8% on the test set. Special attention was paid to the process of optimizing the CNN structure to achieve the highest possible accuracy with the fewest number of network parameters. Full article

Projects related to green aviation designed to achieve fuel savings and emission reductions are increasingly being established in response to growing concerns over climate change. Within the aviation industry, there is a growing trend towards the electrification of aircraft, with more-electric aircraft (MEA) and all-electric aircraft (AEA) being proposed. However, increasing electrification causes challenges with conventional thermal management system (TMS) and power management system (PMS) designs in aircraft. As a result, the integrated power and thermal management system (IPTMS) has been developed for energy-optimised aircraft projects. This review paper aims to review recent IPTMS progress and explore potential design solutions for civil aircraft. Firstly, the paper reviews the IPTMS in electrified propulsion aircraft (EPA), presenting the architectures and challenges of the propulsion systems, the TMS cooling strategies, and the power management optimisation. Then, several research topics in IPTMS are reviewed in detail: architecture design, power management optimisation, modelling, and analysis method development. Through the review of state-of-the-art IPTMS research, the challenges and future opportunities and requirements of IPTMS design are discussed. Based on the discussions, two potential solutions for IPTMS to address the challenges of civil EPA are proposed, including the combination of architecture design and power management optimisation and the combination of modelling and analysis methods. Full article