Search Results (22)

Unmanned Aerial Vehicles (UAVs) have rapidly grown into different essential applications, including surveillance, disaster response, agriculture, and urban monitoring. However, for UAVS to steer safely and autonomously, the ability to detect obstacles and nearby aircraft remains crucial, especially under hard environmental conditions. This study comprehensively analyzes the recent landscape of obstacle and aircraft detection techniques tailored for UAVs acting in difficult scenarios such as fog, rain, smoke, low light, motion blur, and disorderly environments. It starts with a detailed discussion of key detection challenges and continues with an evaluation of different sensor types, from RGB and infrared cameras to LiDAR, radar, sonar, and event-based vision sensors. Both classical computer vision methods and deep learning-based detection techniques are examined in particular, highlighting their performance strengths and limitations under degraded sensing conditions. The paper additionally offers an overview of suitable UAV-specific datasets and the evaluation metrics generally used to evaluate detection systems. Finally, the paper examines open problems and coming research directions, emphasising the demand for lightweight, adaptive, and weather-resilient detection systems appropriate for real-time onboard processing. This study aims to guide students and engineers towards developing stronger and intelligent detection systems for next-generation UAV operations. Full article

This paper presents an integrated digital training twin framework for adaptive aircraft maintenance education, combining real-time competence modeling, algorithmic orchestration, and cloud–edge deployment architectures. The proposed system dynamically evaluates learner skill gaps and assigns individualized training resources through a multi-objective optimization function that balances skill alignment, Bloom’s cognitive level, fidelity tier, and time efficiency. A modular orchestration engine incorporates reinforcement learning agents for policy refinement, federated learning for privacy-preserving skill analytics, and knowledge graph-based curriculum models for dependency management. Simulation results were conducted on the Pneumatic Systems training module. The system’s validation matrix provides full-cycle traceability of instructional decisions, supporting regulatory audit-readiness and institutional reporting. The digital training twin ecosystem offers a scalable, regulation-compliant, and data-driven solution for next-generation aviation maintenance training, with demonstrated operational efficiency, instructional precision, and extensibility for future expansion. Full article

The present paper illustrates the design space exploration of a supersonic mixed-flow turbofan engine for civil applications. The aircraft platform selected is a 10-passenger business jet, cruising at Mach 1.6. To overcome noise limitations at take-off, an alternative engine architecture with additional exhaust nozzle variability, to overcome the take-off noise limit, is proposed. The fully variable area nozzle configuration allows for an overall 15% weight reduction against a partially variable area nozzle architecture. In terms of overall aircraft mission fuel burn, it shows an 8% mission fuel burn reduction against the partially variable area nozzle architecture, with a final fuel efficiency of 11.4 pax-mile/us gallon. Full article

A novel microstructurally controlled graded micro-porous material was developed and experimentally validated for noise reduction through a normal incidence impedance test. Extensive parametric studies were conducted to understand the influence of test specimen size, particle size, porosity, pore size, and its distribution on acoustic absorption and transmission loss. Based on previous research, this study evaluates the application of graded microporous material as an acoustic liner technology for aircraft turbomachine engines. The liner was fabricated in eight 45° segments, assembled in an aluminum test rig, and tested on NASA Glenn Research Center’s Advanced Noise Control Fan (ANCF) low-speed test bed for tonal and broadband noise. The study demonstrates that microstructurally controlled graded microporous material is very effective in dissipating sound energy with reductions in tonal sound pressure level (SPL) of 2 to 13 dB at blade passing frequencies and reductions in broadband SPL of about 2 to 3 dB for the shaft order greater than 40. While the proposed two-layer graded liner model successfully validated the concept, additional design optimization is needed to enhance performance further. This work highlights the potential of graded microporous material as next-generation acoustic liners, offering lightweight, efficient, and scalable aircraft engine noise reduction solutions. Full article

Presented in this paper is the Impact Monitor framework and interactive Dashboard Application (DA) validated through a use case, focusing on investigating the viability and competitiveness of future propulsion architectures for next-generation aircraft concepts. This paper presents a novel collaborative framework for integrated aircraft-level assessments, focusing on secure, remote workflows that protect intellectual property (IP) while enabling comprehensive and automated analyses. The research addresses a key gap in the aerospace domain: the seamless matching and sizing of aircraft engines within an automated workflow that integrates multiple tools and facilitates real-time data exchanges. Specifically, thrust requirements are iteratively shared between aircraft and engine modeling environments for synchronized sizing. Subsequently, the fully defined aircraft data are transferred to other tools for trajectory analysis and emissions and other assessments. The Impact Monitor framework and Dashboard Application demonstrate improved efficiency and data security, promoting effective collaboration across institutions and industry partners. Full article

Compliant wing morphing devices deal with controlled and smooth adaptation of the subcomponents’ shape to external conditions. Their structural stiffness distribution, typically resulting from an optimization design process, is tailored to ensure large deformations and sufficient robustness while preserving a given form under the action of the aerodynamic loads and the internal force system. Within the European project HERWINGT (Hybrid Electric Regional Wing Integration Novel Green Technologies), supported by the Clean Aviation Joint Undertaking (CAJU), a compliant morphing flap (MF) concept has been developed by CIRA to implement adaptive capability for a strut-braced wing of the next generation Hybrid Electric Regional Aircraft. Its aim is to achieve remarkable high-lift performance improvement and related reduction of fuel consumption per flight. Specifically, the work focuses on the evolution of the conceptual architecture of the MF developed across the HERWINGT project, which was investigated in terms of preliminary design and has always accounted for actuation system integration aspects. A step-by-step design approach involving sensitivity finite elements analyses has been then carried out on two MF configurations; the technical outcomes resulting from the development of each of them have been critically analyzed and herein reported. Finally, justifications are provided for all the future adoptable engineering solutions. Full article

In this paper, developed in the context of the Clean Sky 2 project SIENA (Scalability Investigation of hybrid-Electric concepts for Next-generation Aircraft), an extensive analysis is carried out to identify and accelerate the development of innovative propulsion technologies and architectures that can be scaled across five aircraft categories, from small General Aviation airplanes to long-range airliners. The assessed propulsive architectures consider various components such as batteries and fuel cells to provide electricity as well as electric motors and jet engines to provide thrust, combined to find feasible aircraft architectures that satisfy certification constraints and deliver the required performance. The results provide a comprehensive analysis of the impact of key technology performance indicators on aircraft performance. They also highlight technology switching points as well as the potential for scaling up technologies from smaller to larger aircraft based on different hypotheses and assumptions concerning the upcoming technological advancements of components crucial for the decarbonization of aviation. Given the considered scenarios, the common denominator of the obtained results is hydrogen as the main energy source. The presented work shows that for the underlying models and technology assumptions, hydrogen can be efficiently used by fuel cells for propulsive and system power for smaller aircraft (General Aviation, commuter and regional), typically driven by propellers. For short- to long-range jet aircraft, direct combustion of hydrogen combined with a fuel cell to power the on-board subsystems appears favorable. The results are obtained for two different temporal scenarios, 2030 and 2050, and are assessed using Payload-Range Energy Efficiency as the key performance indicator. Naturally, introducing such innovative architectures will face a lack of applicable regulation, which could hamper a smooth entry into service. These regulatory gaps are assessed, detailing the level of maturity in current regulations for the different technologies and aircraft categories. Full article

Innovative structures technologies can contribute to increasing the sustainability of next-generation aircraft. Advanced multi-disciplinary physics models, combined with data-based models, are needed to obtain optimized structures with maximum contributions to sustainability throughout the life cycle. Such models are needed for next-generation aircraft products, for better production of their parts, and for representative testing of their innovative systems. Modeling challenges addressed recently will be presented and illustrated in their industrial context. In particular, fast in-line detection of defects in large composite aircraft parts during their high-rate production, induction welding of thermoplastic carbon-fiber reinforced parts, and accurate design of composite fan blades for wind tunnel testing of fuel-efficient Ultra-High Bypass Ratio (UHBR) turbofan engines will be presented. Full article

The noise of next-generation supersonic civil aircraft can become a significant nuisance for the population in the vicinity of airports. This study investigates the efficiency of the noise control approach for a notional supersonic civil aircraft at takeoff, based on the implementation of a variable noise reduction system (VNRS) with thrust control. Noise levels are computed with a decoupling approach, where the engine noise data and the flight trajectory are calculated independently. It is shown that implementation of the VNRS for the supersonic civil aircraft could lead to a reduction in the certification noise levels at the lateral and flyover measurement points by about 4 EPNdB. The effect of VNRS on noise levels for two allowable positions of the lateral certification point (on the sideline and on the extended runway centerline) is considered and compared for the first time. It is found that the cumulative noise reduction at the flyover and lateral certification point due to the VNRS is larger by 0.8 EPNdB for the position of the lateral certification point on the sideline than for the position on the extended runway centerline. Full article

The evolution of aircraft wing development has seen significant progress since the early days of aviation, with static testing emerging as a crucial aspect for ensuring safety and reliability. This study focused specifically on the engineering phase of static testing for the Clean Sky 2 T-WING project, which is dedicated to testing the innovative composite wing of the Next-Generation Civil Tiltrotor Technology Demonstrator. During the design phase, critical load cases were identified through shear force/bending moment (SFBM) and failure mode analyses. To qualify the wing, an engineering team designed a dedicated test rig equipped with hydraulic jacks to mirror the SFBM diagrams. Adhering to specifications and geometric constraints due to several factors, the jacks aimed to minimize the errors (within 5%) in replicating the diagrams. An effective algorithm, spanning five phases, was employed to pinpoint the optimal configuration. This involved analyzing significant components, conducting least square linear optimizations, selecting solutions that met the directional constraints, analyzing the Pareto front solutions, and evaluating the external jack forces. The outcome was a test rig setup with a viable set of hydraulic jack forces, achieving precise SFBM replication on the wing with minimal jacks and overall applied forces. Full article

Scientific research studies on jet noise generation have been ongoing since the early 1950s, when turbojets were first used in commercial aircraft. Several numerical methods have been developed with the aim of reducing the environmental issues related to the impact of jet noise on community annoyance. Among them, the development of fast and comprehensive tools for jet noise prediction captured the attention of researchers and engineers, being very useful in the preliminary design phase of aircraft engines. This work deals with an extensive survey of James R. Stone’s models, initially formulated for the National Aeronautics and Space Administration (NASA) by Modern Technologies Corporation (MTC), and their implementation in a contemporary numerical framework. The models and their implementation are validated by simulating different engine settings and nozzle configurations taken from the literature with the main scope of highlighting the strengths and weaknesses of the different semi-empirical formulations and setting guidelines for their effective use during the design phases of the next generation of supersonic aircraft. Full article

Machine learning prognosis for condition monitoring of safety-critical systems, such as aircraft engines, continually faces challenges of data unavailability, complexity, and drift. Consequently, this paper overcomes these challenges by introducing adaptive deep transfer learning methodologies, strengthened with robust feature engineering. Initially, data engineering encompassing: (i) principal component analysis (PCA) dimensionality reduction; (ii) feature selection using correlation analysis; (iii) denoising with empirical Bayesian Cauchy prior wavelets; and (iv) feature scaling is used to obtain the required learning representations. Next, an adaptive deep learning model, namely ProgNet, is trained on a source domain with sufficient degradation trajectories generated from PrognosEase, a run-to-fail data generator for health deterioration analysis. Then, ProgNet is transferred to the target domain of obtained degradation features for fine-tuning. The primary goal is to achieve a higher-level generalization while reducing algorithmic complexity, making experiments reproducible on available commercial computers with quad-core microprocessors. ProgNet is tested on the popular New Commercial Modular Aero-Propulsion System Simulation (N-CMAPSS) dataset describing real flight scenarios. To the extent we can report, this is the first time that all N-CMAPSS subsets have been fully screened in such an experiment. ProgNet evaluations with numerous metrics, including the well-known CMAPSS scoring function, demonstrate promising performance levels, reaching 234.61 for the entire test set. This is approximately four times better than the results obtained with the compared conventional deep learning models. Full article

In recent years, global automotive industries are going through a significant revolution from traditional internal combustion engine vehicles (ICEVs) to electric vehicles (EVs) for CO₂ emission reduction. Very similarly, the aviation industry is developing towards more electric aircraft (MEA) in response to the reduction in global CO₂ emission. To promote this technology revolution and performance advancement, plenty of electronic devices with high heat flux are implemented on board automobiles and aircraft. To cope with the thermal challenges of electronics, in addition to developing wide bandgap (WBG) semiconductors with satisfactory electric and thermal performance, providing proper thermal management solutions may be a much more cost-effective way at present. This paper provides an overview of the thermal management technologies for electronics used in automobiles and aircraft. Meanwhile, the active methods include forced air cooling, indirect contact cold plate cooling, direct contact baseplate cooling, jet impingement, spray cooling, and so on. The passive methods include the use of various heat pipes and PCMs. The features, thermal performance, and development tendency of these active and passive thermal management technologies are reviewed in detail. Moreover, the environmental influences introduced by vibrations, shock, acceleration, and so on, on the thermal performance and reliability of the TMS are specially emphasized and discussed in detail, which are usually neglected in normal operating conditions. Eventually, the possible future directions are discussed, aiming to serve as a reference guide for engineers and promote the advancement of the next-generation electronics TMS in automobile and aircraft applications. Full article

The aerospace industry faces constantly increasing demands on performance and reliability, especially within the vital area of engine development. New technologies are needed in order to push the limits of high precision manufacturing processes for the next generation of aircraft engines. An increased use of in-line data collection in manufacturing is creating an opportunity to individualize each assembly operation rather than treating them identically. Welding is common in this context, and the interaction between welding distortion and variation in part geometries is difficult to predict and manage in products with tight tolerances. This paper proposes an approach based on the Digital Twin paradigm, aiming to increase geometrical quality by combining the novel SCV (Steady-state Convex hull Volumetric shrinkage) method for non-nominal welding simulation with geometrical data collected from 3D scanning of parts. A case study is presented where two parts are scanned and then welded together into an assembly. The scan data is used as input for a non-nominal welding simulation, and the result of the simulation is compared directly to scan data from the real welded assembly. Three different welding simulation methods are used and assessed based on simulation speed and ability to predict the real welding result. The segmented SCV method for welding simulation shows promising potential for this implementation, delivering good prediction accuracy and high simulation speed. Full article

New propulsion systems in aircrafts must meet strict regulations and emission limitations. The Flightpath 2050 goals set by the Advisory Council for Aviation Research and Innovation in Europe (ACARE) include reductions of 75%, 90%, and 65% in CO₂, NO_x, and noise, respectively. These goals are not fully satisfied by marginal improvements in gas turbine technology or aircraft design. A novel control design procedure for the next generation of turbofan engines is proposed in this paper to improve Full Authority Digital Engine Control (FADEC) systems and reduce the emission levels to meet the Flightpath 2050 regulations. Hence, an Adaptive Network–based Fuzzy Inference System (ANFIS), nonlinear autoregressive network with exogenous inputs (NARX) techniques, and the block-structure Hammerstein–Wiener approach are used to develop a model for a turbofan engine. The Min–Max control structure is chosen as the most widely used practical control algorithm for gas turbine aero engines. The objective function is considered to minimize the emission level for the engine in a pre-defined maneuver while keeping the engine performance in different aspects. The Genetic Algorithm (GA) is applied to find the optimized control structure. The results confirm the effectiveness of the proposed approach in emission reduction for the next generation of turbofan engines. Full article