Modelling of a Hybrid-Electric Light Aircraft

Abstract The European Research and Innovation Agenda as well as the NASA long-term programs have set ambitious targets in terms of emission reduction for the aviation industry. Continuous improvements of conventional technologies will not be enough to fulfil these ambitious requirements; there is a need for revolutionary aircraft concepts and/or radical innovative systems. One such concept is to use a hybrid-electric propulsion system. The CIRA and the Department of Industrial Engineering of the University of Naples "Federico II" have started a joint program in order to develop models and technologies related to the electrification of propulsive system in aviation. The aim of this work is, then, the exploration of possible benefits of hybrid-electric propulsion with a focus on general aviation and selecting appropriate missions. The hybrid-electric system has been designed assembling elements/systems all commercially available, realizing a very simple parallel layout, classifiable as "minimal hybrid". Furthermore, such hybrid-electric system, -inclusive of energy storage system, transmission system, power management system, etc.- has been conceived to fit the original ICE requirements in term of weight, volume and max power at take-off. In this study, a simple model to evaluate the performances of a light aircraft equipped with a hybrid-electric propulsive system has been developed. The approach adopted combine the so-called 0D/1D simulation to evaluate the "single" ICE performances with a simple engineering modeling which allows the performances evaluation of the integrated power plant. The application of model for a simple transfer mission leads to fuel saving up to 20% while for classical training mission, where pilots make numerous run(lap) "touch –and-go", the fuel saving can reach a significative 30%

Is it really advantageous to operate proximal femoral fractures within 48 h from diagnosis? – A multicentric retrospective study exploiting COVID pandemic-related delays in time to surgery

Objectives: Hip fractures in the elderly are common injuries that need timely surgical management. Since the beginning of the pandemic, patients with a proximal femoral fracture (PFF) experienced a delay in time to surgery. The primary aim of this study was to evaluate a possible variation in mortality in patients with PFF when comparing COVID-19 negative versus positive. Methods: This is a multicentric and retrospective study including 3232 patients with PFF who underwent surgical management. The variables taken into account were age, gender, the time elapsed between arrival at the emergency room and intervention, pre-operative American Society of Anesthesiology score, pre-operative cardiovascular and respiratory disease, and 10-day/1-month/6-month mortality. For 2020, we had an additional column, “COVID-19 swab positivity.” Results: COVID-19 infection represents an independent mortality risk factor in patients with PFFs. Despite the delay in time-to-surgery occurring in 2020, no statistically significant variation in terms of mortality was detected. Within our sample, a statistically significant difference was not detected in terms of mortality at 6 months, in patients operated within and beyond 48 h, as well as no difference between those operated within or after 12/24/72 h. The mortality rate among subjects with PFF who tested positive for COVID-19 was statistically significantly higher than in patients with PFF who tested. COVID-19 positivity resulted in an independent factor for mortality after PFF. Conclusion: Despite the most recent literature recommending operating PFF patients as soon as possible, no significant difference in mortality was found among patients operated before or after 48 h from diagnosis

Development of a Lumped Parameter Model for an Aeronautic Hybrid Electric Propulsion System

This paper describes a case study for applying a hybrid electric propulsion system for general aviation aircraft. The work was performed by a joint team from the Centro Italiano Ricerche Aerospaziali (CIRA) and the Department of Industrial Engineering of the University of Naples Federico II. The use of electric and hybrid electric propulsion for aircraft has gained widespread and significant attention over the past decade. The driver of industry interest has principally been the need to reduce the emissions of combustion engine exhaust products and noise; however, studies have revealed the potential for overall improvement in the energy efficiency and mission flexibility of new aircraft types. The goal of the present study was to demonstrate the feasibility of aeronautic parallel hybrid electric propulsion for light aircraft, varying mission profiles and electric configurations. Through the creation and application of a global model with AMESim® software, in which every aspect of the components chosen by the industrial partners can be represented, some interesting studies were carried out. The numerical model used was more complete and more accurate compared to some others available in the literature. In particular, it was confirmed that, for particular missions, integrating state-of-the-art technologies provides notable advantages for aircraft hybrid electric propulsion for light aircraft

Modelling of a Hybrid-Electric Light Aircraft

The European Research and Innovation Agenda as well as the NASA long-term programs have set ambitious targets in terms of emission reduction for the aviation industry. Continuous improvements of conventional technologies will not be enough to fulfil these ambitious requirements; there is a need for revolutionary aircraft concepts and/or radical innovative systems. One such concept is to use a hybrid-electric propulsion system. The CIRA and the Department of Industrial Engineering of the University of Naples “Federico II” have started a joint program in order to develop models and technologies related to the electrification of propulsive system in aviation. The aim of this work is, then, the exploration of possible benefits of hybrid-electric propulsion with a focus on general aviation and selecting appropriate missions. The hybrid-electric system has been designed assembling elements/systems all commercially available, realizing a very simple parallel layout, classifiable as “minimal hybrid”. Furthermore, such hybrid-electric system, -inclusive of energy storage system, transmission system, power management system, etc.- has been conceived to fit the original ICE requirements in term of weight, volume and max power at take-off. In this study, a simple model to evaluate the performances of a light aircraft equipped with a hybrid-electric propulsive system has been developed. The approach adopted combine the so-called 0D/1D simulation to evaluate the “single” ICE performances with a simple engineering modeling which allows the performances evaluation of the integrated power plant. The application of model for a simple transfer mission leads to fuel saving up to 20% while for classical training mission, where pilots make numerous run(lap) “touch –and-go” , the fuel saving can reach a significative 30%

Modelling of a Hybrid-Electric Light Aircraft

Abstract The European Research and Innovation Agenda as well as the NASA long-term programs have set ambitious targets in terms of emission reduction for the aviation industry. Continuous improvements of conventional technologies will not be enough to fulfil these ambitious requirements; there is a need for revolutionary aircraft concepts and/or radical innovative systems. One such concept is to use a hybrid-electric propulsion system. The CIRA and the Department of Industrial Engineering of the University of Naples "Federico II" have started a joint program in order to develop models and technologies related to the electrification of propulsive system in aviation. The aim of this work is, then, the exploration of possible benefits of hybrid-electric propulsion with a focus on general aviation and selecting appropriate missions. The hybrid-electric system has been designed assembling elements/systems all commercially available, realizing a very simple parallel layout, classifiable as "minimal hybrid". Furthermore, such hybrid-electric system, -inclusive of energy storage system, transmission system, power management system, etc.- has been conceived to fit the original ICE requirements in term of weight, volume and max power at take-off. In this study, a simple model to evaluate the performances of a light aircraft equipped with a hybrid-electric propulsive system has been developed. The approach adopted combine the so-called 0D/1D simulation to evaluate the "single" ICE performances with a simple engineering modeling which allows the performances evaluation of the integrated power plant. The application of model for a simple transfer mission leads to fuel saving up to 20% while for classical training mission, where pilots make numerous run(lap) "touch –and-go", the fuel saving can reach a significative 30%

Modeling and Investigation of a Turboprop Hybrid Electric Propulsion System

Hybrid electric propulsion in the aviation field is becoming an effective alternative propulsion technology with potential advantages, including fuel savings, lower pollution, and reduced noise emission. On the one hand, the aeroengine manufacturers are working to improve fuel consumption and reduce pollutant emissions with new combustion systems; on the other hand, much attention is given to reducing the weight of the batteries increasing the energy density. Hybrid electric propulsion systems (HEPS) can take advantage of the synergy between two technologies by utilizing both internal combustion engines (ICEs) and electric motors (EMs) together, each operating at their respective optimum conditions. In the present work, some numerical investigations were carried out by using a zero-dimensional code able to simulate the flight mission of a turboprop aircraft, comparing fuel consumption and pollutant emissions of the original engine with other two smaller gas turbines working in hybrid configuration. An algorithm has been implemented to calculate the weight of the batteries for the different configurations examined, evaluating the feasibility of the hybrid propulsion system in terms of number of non-revenue passengers

Design and Development of Hybrid-Electric Propulsion Model for Aeronautics

Nowadays, worldwide environmental issue, associated to reduction of pollutant and greenhouse emissions are gaining considerable attention. Aviation sector contribution to the whole CO2 released accounts to around 2%, but it is expected to grow in the next future due to increase of demand. Probably, combustion engine design and fuel efficiency have already reached their optimum technology level and only a breakthrough as hybrid-electric propulsion could be able to satisfy the new international more demanding requirements. However, an improvement of the technology readiness level of hybrid-electric propulsion is strongly necessary and many operational and safety challenges should be addressed. In the work here reported, a hybrid-electric model was designed and developed for general aviation aircrafts, by means of the Mathworks® Matlab – Simulink 1D/0D simulation environment. Both thermal and electric energy storage units, transmission systems and power management devices were considered and the overall performances were evaluated during cruise phase and a conventional training mission, characterized by several run(lap) “touch-and-go”. Furthermore, an innovative mathematical methodology was implemented for battery pack discharge profile interpolation. Finally, reliability and accuracy of the new proposed model were evaluated through comparison with the commercial code Simcenter AMESim® software and an average bias only equal to 5% was achieved