Numerical investigation of the performance of Contra-Rotating Propellers for a Remotely Piloted Aerial Vehicle

Abstract The present work aims at the numerical prediction of the performance of a Contra-Rotating Propellers (CRP) system for a Remotely Piloted Aerial Vehicles (RPAV). The CRP system was compared with an equivalent counter-rotating propellers configuration which was set by considering two eccentric propellers which were rotating at the same speed. Each contra-rotating test case was built by varying the pitch angle of blades of the rear propeller, while the front propeller preserved the original reconstructed geometry. Several pitch configurations and angular velocities of the rear propeller was simulated. Comparisons showed an improvement of the propulsive efficiency of the contra-rotating configuration in case of larger pitch angles combined with slower angular velocities of the rear propeller

A General Platform for the Modeling and Optimization of Conventional and More Electric Aircrafts

The present study aims at the implementation of a Matlab/Simulink environment to assess the performance (thrust, specific fuel consumption, aircraft/engine mass, cost, etc.) and environmental impact (greenhouse and pollutant emissions) of conventional and more electric aircrafts. In particular, the benefits of adopting more electric solutions for either aircrafts at given missions specifications can be evaluated. The software, named PLA.N.E.S, includes a design workflow for the input of aircraft specification, kind of architecture (e.g. series or parallel) and for the definition of each component including energy converter (piston engine, turboprop, turbojet, fuel cell, etc.), energy storage system (batteries, super-capacitors), auxiliaries and secondary power systems. It is also possible to setup different energy management strategies for the optimal control of the energy flows among engine, secondary equipment and storage systems during the mission. The tool is designed to be integrated with a multi-objective optimization environment. In the present investigation the tools has been applied to a regional airliner (ATR 72-600) as a case study and two options for the propulsion system were considered: conventional and More Electric Aircraft. In order to validate the proposed turboprop model, the results obtained with PLA.N.E.S. were compared to nominal literature data and numerical values obtained with the Gas Turbine Simulation Program (GSP)

MEA - Gestione ibrida dell’energia per applicazioni aeronautiche

Progetto MEA (2014-2016) - Gestione ibrida dell’energia per applicazioni aeronautiche. il progetto Hybrid Energy Management si propone di impostare, valutare, analizzare e sviluppare architetture propulsive ibride per applicazioni UAV e Aviazione Generale che permettano di ottimizzare le prestazioni in termini di gestione dell’energia a bordo velivolo. Partners: Avio s.p.a., Istituto di Tecnologie Avanzate per l’Energia CNR, Politecnico di Bari. Università del Salento

Coupling principal component analysis-based sensor data reduction techniques and multi-net systems for simultaneous prediction of multi-component degradation levels in hybrid electric rotorcraft engines

Hybrid Electric Power Systems (HEPS) have gained popularity as a more efficient and eco-friendly alternative. However, with increasing system complexity, fault potential rises. The work aims on implementing a diagnostic system for rotorcraft engine health within a hybrid-electric system. Health monitoring tools are still understudied for HEPS, so this work can represent a valid contribution in the literature. The main goal is assessing degradation and monitoring multi-component simultaneous degradation. Various machine learning techniques for Engine Health Monitoring (EHM) have been compared, varying in network architecture and data reduction. A dynamic model of the entire HEPS generated a dataset including fault information. This dataset trained FFNNs to predict performance parameters (PPs) of degraded components from sensor data. The proposed EHM system's efficacy was evaluated by comparing neural network predictions to dynamic model data. Results show that the Multi-net architecture, with distinct networks for each PP, works more effectively reducing training time

Feed-Forward Neural Network for health monitoring of a parallel hybrid electric power system

Hybrid engines are becoming more and more widespread. Electric energy instead is a valid help to reduce the environmental impact. In hybrid engines, the number of components is higher and this results in a decrease in reliability. With Engine Health Monitoring (EHM) we mean the set of techniques used to monitor the health status of a system based on the values assumed by some related parameters. Artificial Intelligence (AI) methods are widely used nowadays in this discipline. In this paper, an EHM approach was developed to monitor the health status of some components constituting an hybrid turboshaft. The dynamic model of the hybrid electric power system is described in an accompanying paper. Feed-Forward Neural Network (FFNN) is used as AI tool to built the just cited system. The engine modelled with Simulink, was used to perform a series of steady-state simulations implementing a degradation condition in some selected components. The degradation condition was simulated by changing the value of the PPs related to each of the selected components. The results of the simulation were used to obtain a dataset useful to train the FFNN to predict the values of the same PPs in a degraded case

Numerical investigation of the performance of Contra-Rotating Propellers for a Remotely Piloted Aerial Vehicle

The present work aims at the numerical prediction of the performance of a Contra-Rotating Propellers (CRP) system for a Remotely Piloted Aerial Vehicles (RPAV). The CRP system was compared with an equivalent counter-rotating propellers configuration which was set by considering two eccentric propellers which were rotating at the same speed. Each contra-rotating test case was built by varying the pitch angle of blades of the rear propeller, while the front propeller preserved the original reconstructed geometry. Several pitch configurations and angular velocities of the rear propeller was simulated. Comparisons showed an improvement of the propulsive efficiency of the contra-rotating configuration in case of larger pitch angles combined with slower angular velocities of the rear propeller

Out-of-Season Epidemic of Respiratory Syncytial Virus during the COVID-19 Pandemic: The High Burden of Child Hospitalization in an Academic Hospital in Southern Italy in 2021

Respiratory syncytial virus (RSV) infection is the most common cause of hospitalization in young children. In the last 2 years, public health measures aimed at controlling the spread of SARS-CoV-2 have affected the epidemiology and seasonality of RSV worldwide. The aim of this descriptive retrospective observational study was to describe the characteristics of children hospitalized with RSV in an academic tertiary care hospital in Southern Italy in 2021. We also investigate the seasonal trends of RSV from 2017 to 2021. The demographic characteristics, comorbidities, clinical data, and coinfections were retrospectively evaluated. Compared with previous seasons, the 2021 outbreak of RSV was characterized by an increased number of patients, with a delayed peak observed in November. Overall, 179 children, including 128 (71.5%) aged p < 0.05 each). History of prematurity was not significantly associated with the presence of coinfections. Because of the high burden of RSV infection and the expected larger RSV epidemics resulting from a greater number of RSV-naïve children, systematic epidemiological and virological surveillance is needed. Appropriate pathways for access to RSV prevention in all infants should also be introduced

Multicentre observational study on practice of prehospital management of hypotensive trauma patients: the SPITFIRE study protocol

Introduction Major haemorrhage after injury is the leading cause of preventable death for trauma patients. Recent advancements in trauma care suggest damage control resuscitation (DCR) should start in the prehospital phase following major trauma. In Italy, Helicopter Emergency Medical Services (HEMS) assist the most complex injuries and deliver the most advanced interventions including DCR. The effect size of DCR delivered prehospitally on survival remains however unclear.Methods and analysis This is an investigator-initiated, large, national, prospective, observational cohort study aiming to recruit &gt;500 patients in haemorrhagic shock after major trauma. We aim at describing the current practice of hypotensive trauma management as well as propose the creation of a national registry of patients with haemorrhagic shock. Primary objective: the exploration of the effect size of the variation in clinical practice on the mortality of hypotensive trauma patients. The primary outcome measure will be 24 hours, 7-day and 30-day mortality. Secondary outcomes include: association of prehospital factors and survival from injury to hospital admission, hospital length of stay, prehospital and in-hospital complications, hospital outcomes; use of prehospital ultrasound; association of prehospital factors and volume of first 24-hours blood product administration and evaluation of the prevalence of use, appropriateness, haemodynamic, metabolic and effects on mortality of prehospital blood transfusions. Inclusion criteria: age &gt;18 years, traumatic injury attended by a HEMS team including a physician, a systolic blood pressure &lt;90 mm Hg or weak/absent radial pulse and a confirmed or clinically likely diagnosis of major haemorrhage. Prehospital and in-hospital variables will be collected to include key times, clinical findings, examinations and interventions. Patients will be followed-up until day 30 from admission. The Glasgow Outcome Scale Extended will be collected at 30 days from admission.Ethics and dissemination The study has been approved by the Ethics committee 'Comitato Etico di Area Vasta Emilia Centro'. Data will be disseminated to the scientific community by abstracts submitted to international conferences and by original articles submitted to peer-reviewed journals