Search Results (24)

The design of low-emission alternative-propulsion aircraft requires multidisciplinary collaboration across distributed academic and industrial environments, challenging the applicability of conventional Multidisciplinary Design Analysis and Optimization (MDAO) frameworks. This paper presents the Holistic Collaborative MDAO Selection (HCMS) methodology, which provides a structured approach for selecting MDAO architectures based on socio-technical feasibility (intellectual property protection, disciplinary autonomy, and IT governance) and computational feasibility (coupling strength and model fidelity). The methodology supports a transition from centralized to distributed workflows while ensuring secure and efficient cross-organizational integration. The approach is demonstrated through a multi-institutional case study of a dual-fuel (hydrogen and kerosene) business jet using Remote Component Environment (RCE) and Common Parametric Aircraft Configuration Schema (CPACS). Results demonstrate that the proposed methodology enables stable and scalable distributed MDAO execution while explicitly accounting for socio-technical constraints, with consistent convergence behavior and communication overhead (approximately 25 s per iteration) remaining small relative to disciplinary computation time. The case study further illustrates the impact of hydrogen integration, showing an increase in operating empty weight of approximately 14.06% for a 600 NM mission and a reduction in kerosene capacity of approximately 12.9%, while enabling hydrogen-powered operation for the primary mission segment. These findings confirm that the proposed framework effectively supports secure, collaborative MDAO under realistic socio-technical constraints while providing meaningful system-level design insights. Full article

The high-speed and high-Reynolds-number conditions encountered in actual flight, coupled with the performance requirements for both low-speed climb and high-speed cruise, pose challenges for boundary-layer transition prediction and optimization in laminar design. Consequently, there are still relatively few mature and applicable high-speed laminar airfoils available. To address the insufficient validation of Reynolds-averaged Navier-Stokes (RANS) models under actual high-speed and high-Reynolds-number (Re > 10⁷) flight conditions, the practical fidelity of the most commonly used $\gamma -{\tilde{R}e}_{\theta t}$ transition model as well as NASA CFL3D solver is systematically assessed based on NASA HSNLF(1)-0213 and Honda SHM-1 high-speed business jet laminar airfoils. To the best of the authors’ knowledge, since there is no available geometry data for the SHM-1 airfoil, this is the first systematic analysis of this airfoil from a perspective other than the design team. Results demonstrate that the $\gamma -{\tilde{R}e}_{\theta t}$ transition model could accurately capture natural transition and separation-induced transition at Reynolds numbers up to 16.2 × 10⁶, while also exhibiting strong robustness against variations in Mach and Reynolds number. Using the HSNLF(1)-0213 as the baseline airfoil and the design conditions of SHM-1, a multi-objective drag-reduction optimization considering climb and cruise performance was then conducted based on the Isight platform. The optimal airfoil achieves 9.53% climb drag reduction and 9.21% cruise drag reduction, revealing that aft-loading and strong favorable pressure gradients are essential to balance lift characteristics and sustain extensive laminar flow at high Reynolds numbers. Full article

This paper presents the development of two adaptive autopilots for the Cessna Citation X business jet aircraft. The two adaptive control strategies, including a dynamic inversion controller and a neural network controller, provide dual adaptation. The control objective consists of tracking the vertical speed, altitude, and heading commands. Dynamic inversion is applied on each output variable, and then the neural network (NN) controller is updated using adaptive law, derived from backpropagation. Dynamic inversion (DI) is achieved locally using a Recursive Least Squares (RLS) algorithm for state estimation. An inner control loop for the pitch, roll and yaw rates is integrated within the autopilots. The longitudinal states were separated from the lateral states in order to differentiate between longitudinal and lateral control. Robustness tests were conducted under turbulence and wind-gust conditions. The autopilot results were compared with flight simulation data from a Cessna Citation X research flight simulator. Results have shown that the autopilots accurately track the vertical speed, altitude and heading reference signals. The flight simulation comparison has shown that the proposed adaptive controllers were better than the one currently on board the Cessna Citation X. Full article

The following paper investigates the feasibility of hybrid-electric propulsion (HEP) for a very light jet (VLJ) business aircraft based on predictions of battery performance for the 15-year timeframe to 2040. Given the unique requirements of a range of between 1100 and 2200 km (600 and 1200 nmi) and a cruise speed of around Mach 0.65, this paper utilizes a time-stepping simulation to determine range for a baseline aerodynamic model over combinations of energy hybridization ratios and battery specific energy densities of $H_E\in [0.0,0.25]$ and $e_{\mathrm{bat}}\in [400,1250]$ Wh/kg for series and parallel architectures. The paper also analyzes fuel and battery energy consumption, battery weight and volume, and finally a typical mission of 1111 km (600 nmi). The results of the paper find that the parallel architecture is better suited to application on very light jets, as it enables a greater maximum range of 1394 km (754 nmi) with a mild energy hybridization of 5% and a battery specific energy density of 1250 Wh/kg for a fixed maximum takeoff weight. Over a typical 1111 km (600 nmi) mission, fuel savings with a parallel architecture are 96 kg (212 lbs) compared to a conventional turbofan, or 7.1% of the total fuel load. Consequently, it is recommended that a hybrid-electric very light jet utilize a mild-hybrid parallel architecture of around 5% energy hybridization and batteries of at least 1250 Wh/kg. Full article

CO₂ emissions continue to rise, along with the associated environmental risks. In response, the United Nations has been promoting the adoption of sustainable practices among businesses worldwide. In parallel, an innovative technology known as additive manufacturing (AM) has emerged over the past four decades. This technology has the potential to be more sustainable than conventional manufacturing (CM) technologies. When metals are used as the material, the process is referred to as metal additive manufacturing (mAM). AM technologies have seven process categories, which include metal mAM processes, most notably powder bed fusion (PBF), directed energy deposition (DED), binder jetting (BJT), material extrusion of metal-filled feedstock, and sheet lamination. Among these, PBF and DED are by far the most widely applied metal AM technologies in both industrial practice and academic research. The use of mAM is increasing; however, is it truly more sustainable than CM? Motivated by this question, a systematic literature review (SLR) was conducted to compare the sustainability impacts of mAM and CM across the three dimensions of sustainability: environmental, economic, and social. The evidence shows mixed sustainability outcomes, which are synthesized later in the conclusions. The sustainability comparison is influenced by factors like part redesign with topological optimization (TO), the material and energy mix used, geometric complexity, production volume per batch, and the boundaries adopted. Economic viability remains critical; companies are unlikely to adopt mAM if it proves more expensive than CM as this could threaten its competitiveness. Social impacts are the least studied dimension, and it is difficult to anticipate the changes that might occur because of such a transition. 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

This paper describes an experimental investigation on the spread of a virus in a business jet cabin and the potential of ionization to reduce the pathogen load. In contrast to priorly investigated recirculation air cleaning, ionization can act directly in the cabin by introducing ions into the supply air. Tests were performed by emitting a surrogate virus through a breathing head in a business jet mock-up. The results allow for the conclusion that ionization technology, along with increased airflow, is a well-suited tool to sanitize cabins. Additionally, the effect of ionization on particles was investigated where it became obvious that the presence of particles reduces the ion level; however, the presence of ions hardly impact particles. Full article

This study explores inlet-related installation effects on next-generation SST aircraft, focusing on supersonic business jets. Using a comprehensive framework with consistent thrust/drag bookkeeping and realistic modeling of inlet losses, including operational limits for “buzz” and distortions, the inlet drag accounts for 8.8% to 14.2% of the installed net thrust during the supersonic segment of the mission. Variable airflow control technology is assessed, with a scheduling methodology developed to optimize the inlet operation by minimizing the installed SFC. The results show that this technology improves the installed SFC by 0.80% during supersonic cruise, enhancing the overall propulsion system performance. Full article

A novel combination of three control systems is presented in this paper: an adaptive control system, a type-two fuzzy logic system, and a super-twisting sliding mode control (STSMC) system. This combination was developed at the Laboratory of Applied Research in Active Controls, Avionics and AeroServoElasticity (LARCASE). This controller incorporates two methods to calculate the gains of the switching term in the STSMC utilizing the particle swarm optimization algorithm: (1) adaptive gains and (2) optimized gains. This methodology was applied to a nonlinear model of the Cessna Citation X business jet aircraft generated by the simulation platform developed at the LARCASE in Simulink/MATLAB (R2022b) for aircraft lateral motion. The platform was validated with flight data obtained from a Level-D research aircraft flight simulator manufactured by the CAE (Montreal, Canada). Level D denotes the highest qualification that the FAA issues for research flight simulators. The performances of controllers were evaluated using the turbulence generated by the Dryden model. The simulation results show that this controller can address both turbulence and existing uncertainties. Finally, the controller was validated for 925 flight conditions over the whole flight envelope for a single configuration using both adaptive and optimized gains in switching terms of the STSMC. Full article

This paper presents a comprehensive comparative study of the resilience of leading edge anti-icing systems on business jets when exposed to severe hailstorm conditions. Using advanced simulation models correlated with experimental data, the study aims to determine the overall effectiveness of these systems when exposed to the adverse effects of hail impact. Key aspects of the study include the examination of system structural response to varying sizes and densities of hailstones, and the impact on the leading edge structural integrity and on the overall aircraft safety. The simulations are designed to replicate realistic hailstorm scenarios, considering factors such as hailstone velocity, size, and impact angle. Results from the study reveal significant differences in the performance of piccolo-tube anti-icing system under hailstorm conditions. The study assesses the operational limitations and the energy absorption of a business jet anti icing system, providing valuable insights for anti-icing robust design in this category. Full article

This paper proposes a novel route optimization framework to solve the problem of instant pick-up and delivery for e-grocery orders. The proposed framework extends the traditional time-windowed package delivery problem. We demonstrate the effectiveness of our approach for this integrated problem using actual delivery data from HepsiJet, a leading e-commerce logistics provider in Turkey. We first employ several machine learning algorithms and simulations to investigate the capacity of the courier. Subsequently, a dynamic route planning workflow is executed with a highly specialized and novel routing algorithm. Our proposed heuristic approach considers combined fleet operations for delivering regular packages originating from a central depot and dynamic e-grocery orders picked up at local supermarkets and delivered to the customers. The heuristic algorithm constitutes k-opt and node transfer operation variations customized for this integrated problem. We report the performance of our approach in problem instances from the literature and instances from HepsiJet’s daily operations, which we also publicly share as new route optimization problem instances. Our results suggest that, despite the more complex nature of the integrated problem, our proposed algorithm and solution framework produce more efficient and cost-effective solutions that offer additional business opportunities for companies such as HepsiJet. The computational analyses reveal that implementing our proposed approach yields significant efficiency gains and cost reductions for the company, with a distance reduction of over 30%, underscoring our approach’s effectiveness in achieving substantial cost savings and enhanced efficiency through integrating two distinct delivery operations. Full article

Natural gas is known as a widely used energy source in residential, business and industrial areas. During the transportation of natural gas by pipelines, accidents occur due to various reasons, which can also lead to gas output. These accidents are events that have the potential to pose important risks in terms of life and property safety, particularly in urban areas and surrounding of pipeline routings. In this study, accident scenarios were generated based on a natural gas distribution pipeline fire that occurred in Istanbul (NW Türkiye) on 28 April 2020 and the impact areas of the jet fire were calculated using the ALOHA program. The effects of source release factors (i.e., pipe length and diameter) and atmospheric conditions (i.e., wind speed, cloud cover, air temperature and relative humidity) on the thermal radiation threat distances associated with jet fire were calculated for the current and worst scenarios. As a result, it was found that pipe length and diameter have a significant effect on threat distances. In addition to the role of the synoptic circulation mechanism on the jet fire for the selected episodic event (position of low/high pressure centers), local atmospheric conditions also have an effect on the threat distance. From the modeling analysis, significant impact of wind speed, air temperature and relative humidity values on the threat distances were found. In the worst scenario, if there were strong northeasterly winds reaching 30.9 m per hour at the time of the jet fire, the threat distances would have been 21 m (red), 28 m (orange) and 42 m (yellow). This case shows that if a natural gas jet fire occurs under the influence of strong northeasterly winds (passing over the Black Sea without encountering any topographic obstacles), poisonous gas will be transported to long distances in a short time and will negatively affect social life and economy. Full article

This article presents single- and multi-disciplinary shape optimizations of a generic business jet wing at two transonic cruise flow conditions. The studies performed are based on two high-fidelity gradient-based optimization tools, assisted by the adjoint method (following both discrete and continuous approaches). Single discipline and coupled multi-disciplinary sensitivity derivatives computed from the two tools are compared and verified against finite differences. The importance of not making the frozen turbulence assumption in adjoint-based optimization is demonstrated. Then, a number of optimization runs, ranging from a pure aerodynamic with a rigid structure to an aerostructural one exploring the trade-offs between the involved disciplines, are presented and discussed. The middle-ground scenario of optimizing the wing with aerodynamic criteria and, then, performing an aerostructural trimming is also investigated. Full article

The aviation industry’s contribution to global greenhouse gas (GHG) emissions has been on an unsteady rise for the past few decades. This paper aims to identify the determinants of increasing GHG emissions in Europe in a dynamic panel setting, paying specific attention to the role of the European Union Emissions Trading System (EU ETS). Unlike previous studies, this paper proposes business tourism spending and capital investment in the tourism and travel industry as explanatory factors together with GDP per capita and jet fuel consumption. Unexpectedly, the EU ETS coverage is found to have an increasing role for GHG emissions from international aviation in countries where the system is put into effect. The results suggest that a more targeted emissions reduction policy needs to be implemented in order to mitigate aviation emissions in the region. Full article

The aviation industry is facing pressure from stakeholders to transform towards greater sustainability. From a managerial and marketing perspective, not only the actual implementation and achievements of sustainability measures, but also their communication to stakeholders is likely to be crucial—and in many cases even legally required. This research evaluates the scope of sustainability and corporate social responsibility (CSR) reporting of Europe’s five largest airline groups for or from the year 2019, just prior the COVID-19 crisis. For this, dedicated sustainability reports and non-financial statements of Air France-KLM, easyJet, International Airlines Group, Lufthansa Group and Ryanair are evaluated and compared in a qualitative content analysis, using the Standards of the Global Reporting Initiative (GRI) as reference categories. The results indicate that the sustainability publications differ by airline business model, as the two low-cost carriers report less content in non-financial statements only, without publishing any standalone sustainability reports. Independent of the business model, most airlines surprisingly neglect the economic dimension of sustainability. The airline sector could improve its sustainability marketing by reporting both their economic, environmental, and social impacts and achievements. Full article