Aerospace applications

To request a copy of a publication send an email to antonio.ficarella02@gmail.com.

2017

“Designing a Hybrid Electric Powertrain for an Unmanned Aircraft with a Commercial Optimization Software”, Donateo T., Ficarella A., SAE International Journal of Aerospace, Volume 10 (2017), http://dx.doi.org/10.4271/2017-01-9000

The design of a hybrid electric powertrain requires a complex optimization procedure because its performance will strongly depend on both the size of the components and the energy management strategy. The problem is particular critical in the aircraft field because of the strong constraints to be fulfilled (in particular in terms of weight and volume). The problem was addressed in the present investigation by linking an in-house simulation code for hybrid electric aircraft with a commercial many-objective optimization software. The design variables include the size of engine and electric motor, the specification of the battery (typology, nominal capacity, bus voltage), the cooling method of the motor and the battery management strategy. Several key performance indexes were suggested by the industrial partner. The four most important indexes were used as fitness functions: electric endurance, fuel consumption, take-off distance and powertrain volume. A design able to fulfill all the targets set by the industrial partner was found using an elimination-by-aspect approach applied to the overall Pareto front. The results of the algorithm were post-processed and some metrics were used to evaluate the performance of the genetic algorithm in solving the proposed optimization problem.

2016

"Development and Validation of a Software Tool for Complex Aircraft Powertrains", T. Donateo, A. Ficarella, L. Spedicato, Advances in Engineering Software, pp. 1-13,

DOI 10.1016/j.advengsoft.2016.01.001, 2016.

A simulation software for the assessment of performance, costs and environmental impact of conventional and advanced configuration aircraft has been developed and validated. The software is named PLA.N.E.S. (PLAtform for New Environment-friendly Solutions), and includes a sizing routine and a mission simulator. The simulation is performed with the so-called backward paradigm, i.e. the flight conditions along the mission (altitude and speed versus time) are assumed to be known. Accordingly, the instantaneous power request of the aircraft to meet that flight mission and the corresponding instantaneous fuel consumption are calculated. In the case of advanced powertrains, it is also possible to choose different energy management strategies for the optimal control of the energy flows among engine, secondary equipment and storage systems during the mission. The components currently modeled in PLA.N.E.S. include energy converters (piston and Wankel engines, turboprop, fuel cell, etc.), energy storage systems (batteries, super-capacitors), auxiliaries and secondary power systems. The tool is designed to be integrated with a multi-objective optimization environment. In the present investigation PLA.N.E.S. has been applied to a Medium Altitude Medium Endurance (MAME) Unmanned Aerial Vehicle (UAV) as a case study to compare an experimentally validated Wankel-based powertrain with a proposed turbocharged diesel piston-prop system.

2015

"GREENING THE PROPULSION: A comparative analysis of advanced more electric solutions for aircraft", Maria Grazia De Giorgi, Teresa Donateo, Stefano Campilongo, Luigi Spedicato, Antonio

Ficarella, Giuseppe Giliberti, 23RD CONFERENCE OF THE ITALIAN ASSOCIATION OF AERONAUTICS AND ASTRONAUTICS, Politecnico di Torino, corso Duca degli Abruzzi, 24 Torino, 17‐19 Novembre 2015

A sizing and simulation platform named PLA.N.E.S. was developed for the optimization of  advanced architectures for aircrafts including more electric and hybrid-electric systems. The simulation software consists of a sizing tool and a backward simulation tool. The sizing tool is used to match the performance of the architecture to the power request of the aircraft at take-off, cruise and climbing and to compare different architectures in terms of aircraft/engine mass, cost, etc. The backward simulation tool is used to assess the performance (thrust, specific fuel consumption) and environmental impact (greenhouse and pollutant emissions) of the selected architecture over a pre-assigned altitude and speed profile versus time. In this way, the benefits of adopting more electric solutions can be evaluated over the entire flight.  In the present investigation PLA.N.E.S is used to compare conventional and more electric architectures for the regional aircraft ATR 72-500 over different mission profiles obtained from a literature survey. A turboprop engine was modelled with a dedicated jet engine performance software to calculate the engine maps to be implemented in PLA.N.E.S. The investigation describes the preliminary results of the project "Greening the Propulsion", presented as part of the Cluster "Aerospace", which aims to strengthen the industrial, scientific and district levels through the involvement of a national system of distinctive competences already involved by Avio in collaboration projects and in other research projects for the development of new technologies for aeronautical and space applications, with the aim to maintain international competitiveness in the champions of the sector. 

"Predictions of Operational Degradation of the Fan Stage of an Aircraft Engine Due to Particulate Ingestion", Maria  Grazia De Giorgi; Stefano  Campilongo; Antonio  Ficarella, JOURNAL OF ENGINEERING FOR GAS TURBINES AND POWER, 137, 052603-1-052603-15, 2015.

A numerical evaluation of the effects of volcanic ash ingestion in a turbofan engine was carried out, with particular regard to the prediction of the erosion damage to fan blades. The ash concentration level examined in the study was below the flight limit because the aim of this study is to investigate the damage due to long-term exposure to low concentration levels. The work aims to the implementation of a numerical methodology that takes into account the geometry change of the fan blades during the exposure to volcanic ash. A dimensional and morphological characterization of a real volcanic ash sample from the Mount Etna volcano has been performed to model the particle flow dynamics using a computational fluid dynamics (CFD) code. The fan performance in terms of the total pressure increase was calculated for both the baseline and damaged geometries to quantify the performance deterioration trend with respect to the particle exposure time. For the calculation of the eroded fan performance, two different numerical approaches were considered. In the first approach, the erosion rate (ER) was evaluated based on the initial blade geometry and was held constant. In the second approach, the ER was updated as the erosion of the blade continued. The second approach shows a higher deterioration of the pressure rise across the fan, suggesting that the variation of the ER due to the blade shape modification cannot be neglected in the calculations.

"Embedded sensor/actuator system for aircraft active flow separation control", Francioso, L.; De Pascali, C.; Casino, F.; Siciliano, P.; De Giorgi, M.G.; Campilongo, S.; Ficarella, A., IEEE - Institute of Electrical and Electronics Engineers, New York, 1-4, 2015.

This work reports on finite element method (FEM) design and fabrication of low cost capacitive pressure sensors for aircraft applications; this work is part of a research activity aimed to develop an embedded sensor-actuator system composed by multi-measure points pressure sensors for flow turbulence detection and coupled plasma actuators for control of separated flows on aircraft wings structures. The system uses sensors feedback information to provide fast reattachment of boundary layer separation flow on the suction surface of regional aircraft vehicles. Flow separation has great impact on the performance and safety of an aircraft and it can be predicted by quantifying the pressure gradients along the wing wall. Considering the absolute pressure values on a NACA 0012 profile as a function of the angle of attack, high sensitivity measurements of differential pressure can be obtained by positioning the sensor-nodes at points on the airfoil surface where the P/Pstall ratio between the absolute pressure at different angles of attack and the pressure measured in stall condition is maximized.

2014

“Investigating Flow Dynamics with Wireless Pressure Sensors Network”, Maria Grazia De Giorgi, Riccardo Brama, Piergiuseppe Tundo, Silvia Capone, Valerio Giampà, Angelo Malvasi, Luca Francioso, Chiara De Pascali, Stefano Campilongo, 12th IEEE EUC '14: Special Session on "Enabling Technologies for Future Airborne WSNs" 26‐28 Agosto 2014, Milano, ISBN: 978‐076955249‐1,doi: 10.1109/EUC.2014.36

Wireless sensors networks enable the chance to investigate with enhanced freedom physical phenomena, aiming to increase the informative content obtained by sensors measurements. In this work we will focus on a system allowing to experimentally measure pressure profiles obtained from sensor nodes deployed on a NACA0012 aircraft wing model. By exploiting measurements gathered from sensors, allowing to measure pressure fluctuations of ±600Pa with a resolution of 4Pa, together with results obtained by Computational Fluid Dynamics (CFD) models, the system enables extracting flow profile, thus obtaining information on flow separation and stall phenomenon. Wireless measures are delivered with an enhanced version of IEEE802.15.4e, allowing to decrease power consumption by a factor of 7. Packet routing, based on Routing Protocol for Low-Power and Lossy Networks (RPL), has been improved by means of a newly introduced Lifetime and Latency Aggregatable Metric (L2AM) leading to a 18% increased network lifetime.

"Strategic Research & Innovation Agenda - Italia - Volume 2", Advisory Council for Aviation Research and Innovation in Europe - Italia, Ass. Italiana di Aeronautica e Astronautica, ROMA, 1-112, 2014.

"Strategic Research & Innovation Agenda - Italia - Volume 1", Advisory Council for Aviation Research and Innovation in Europe - Italia, Ass. Italiana di Aeronautica e Astronautica, ROMA, 1-120, 2014.

"Strategic Research & Innovation Agenda - Italia - Executive Summary", Advisory Council for Aviation Research and Innovation in Europe - Italia, Ass. Italiana di Aeronautica e Astronautica, ROMA, 1-8, 2014.

"Aircraft Distributed Flow Turbulence Sensor Network with Embedded Flow Control Actuators", Luca  Francioso; Chiara De  Pascali; Pietro  Siciliano; Maria Grazia De  Giorgi; Elisa  Pescini; Antonio  Ficarella, Institute of Electrical and Electronics Engineers Inc, New York, , 1, 185-192, 2014.

Several active and passive flow control systems are studied to improve the performances of fluid machineries and to increase aerodynamic efficiency of propulsion systems. Among all the well-known active flow control devices, the dielectric barrier discharge plasma actuator (PA) is in full expansion and of great interest in the scientific community. A PA modifies the following behaviour of a fluid by providing an electronically controllable disturbance that brings to drag reduction, flow separation control, enhanced mixing, and noise suppression. PA is potentially easy to construct, has no moving parts and has low power requirements. This leads to its possible applications for separation control in low pressure turbine blade and compressor cascade, tip clearance flow control and compressor stability range extension. The present work reports the design and fabrication of cheap Kapton-based flow turbulence capacitive sensors able to be embedded into aircraft wing profiles and airfoil structures for critical turbulence conditions detection and early-detected separated flows control. The embedded system will provide a Kapton-foil based pressure detection and linear/synthetic jet plasma actuators working in feedback, for prevention and active reduction of separated flow for regional aircraft applications.

172) "A General Platform for the Modeling and Optimization of Conventional and More Electric Aircrafts", T. Donateo, M.G. De Giorgi, A. Ficarella, E. Argentieri, E. Rizzo, SAE Technical Paper 2014-01-2187, doi:10.4271/2014-01-2187, 2014.

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).

2013

"Experimental and Numerical Study of Particle Ingestion in Aircraft Engine", Maria Grazia De Giorgi, Stefano Campilongo, Antonio Ficarella, Mauro Coltelli, Valerio Pfister, Francesco Sepe, ASME Paper GT2013-95662, Proceedings of ASME Turbo Expo 2013: Turbine Technical Conference and Exposition, GT2013, June 3-7, San Antonio, Texas, USA, 2013.

This study is focused on volcanic ash ingestion in aircraft engines, that can lead to slow but constant deterioration in engine performance and engine failure because of the mechanical damages to the wall surface. In particular the particles that impact on blades surfaces cause erosion damage and permanent losses in engine performance. Aircraft engine fans could be severely damaged by the ash flow.. In order to clarify the erosion phenomenon the fan has been simulated through the general-purpose CFD code and the numerical simulations were performed using the Reynolds–Averaged Navier–Stokes (RANS). After validating the numerical modeling of the flow without erosion by comparisons with experimental data in literature, a surface injection of a discrete phase has been introduced in order to evaluate particle ingestion of volcanic ash. This phenomenon is a typical gas-particle two-phase turbulent flow and a multi-physics problem where the flow field, particle trajectory and wall deformation interact with among others. A wide experimental investigation has been carried out on an ash sample from Etna volcano. In particular a sieve analysis to obtain particles dimensional distribution and an analysis of SEM images to calculate particles shape factor. These data were used to modeling the particle injection in the CFD model. The numerical investigation was aimed to clarify the effects of particle erosion and to evaluate the change of the flow field in the case of eroded blades. By erosion rate patterns, the eroded mass was estimated and it was used to model the eroded geometry, by a user routine implemented in the dynamic mesh module of the code. So the performances of the damaged fan were estimated and compared with the baseline geometry without erosion.