Retrofitting Cost Modeling in Aircraft Design

Aircraft retrofitting is a challenging task involving multiple scenarios and stakeholders. Providing a strategy to retrofit an existing platform needs detailed knowledge of multiple aspects, ranging from aircraft performance and emissions, development and conversion costs to the projected operating costs. This paper proposes a methodology to account for retrofitting costs at an industrial level, explaining the activities related to such a process. Costs are mainly derived from three contributions: development costs, conversion costs and equipment acquisition costs. Different retrofitting packages, such as engine conversion and onboard systems electrification, are applied in the retrofitting of an existing 90 PAX regional turbofan aircraft, highlighting the impact on both aircraft performance and industrial costs. Multiple variables and scenarios are considered regarding trade-offs and decision-making, including the number of aircraft to be retrofitted, the heritage of an aircraft and its utilization, the fuel price and the airport charges. The results show that a reduction of 15% in fuel demand and emissions are achievable, considering a fleet of 500 platforms, through a conspicuous investment of around EUR 20 million per aircraft (50% of the estimated price). Furthermore, depending on the scenarios driven by the regulatory authorities, governments or airlines, this paper provides a useful methodology to evaluate the feasibility of retrofitting activities

Noise, emissions and costs trade factors for regional jet platforms using a new software for aircraft preliminary design

A multidisciplinary analysis approach plays a very important role in the development of future transport aircraft, being able to interconnect all aircraft-related subjects and suppliers. A major issue, which has prevented aircraft manufacturers from implementing efficient and cost-effective design processes, is the loose integration of engine models into iterative aircraft design workflows. The continuous improvement of computer calculation capabilities over years has allowed the growth of a large family of software dedicated to aircraft preliminary design activities concerning also multi-disciplinary analyses, and optimizations. In this context, a new software for aircraft preliminary design, multi-disciplinary analyses and optimizations named JPAD (Java toolchain of Programs for Aircraft Design) has been developed at the University of Naples Federico II. The main purpose of this paper is to show the capabilities of the JPAD software applied to typical preliminary design problems. Thus, results of the activities carried out by means of JPAD in the scope of the Work Package 2 (WP2) of the European CleanSky2 project ADORNO will be shown. Those will concern trade factors and response surfaces related to environmental noise, DOC, and pollutant emissions (linked to the design mission block fuel) for a Rear-Mounted engines (RM) reference 2014 aircraft configuration

A Java toolchain of programs for aircraft design

The purpose of this work is to provide a comprehensive overview of JPAD (Java toolchain of Programs for Aircraft Design), a java-based framework conceived as a fast and efficient tool useful as support in the preliminary design phases of an aircraft, and during its optimization process. The software platform is made to perform fast multi-disciplinary analysis of an established aircraft configuration and to search for an optimized configuration in a domain, whose boundaries are defined by the user. The following sections will focus on the description of the software structure and on the results obtained from a case study carried out assuming as baseline a regional turboprop aircraft model similar to ATR-72

Aerodynamics characteristics of an innovative large turboprop through wind tunnel tests including propulsive effects

This paper deals with the assessment of both longitudinal and directional aerodynamic characteristics of an innovative large capacity turboprop aircraft by means of a wind tunnel test campaign on a scaled model. The aircraft under investigation is an innovative turboprop platform providing for a three lifting surface layout and a rear engine installation. The scope of this research is to deeply investigate the aerodynamic behavior of such an innovative platform to assess the aerodynamic interferences among the aircraft components. In particular, the effects of the third lifting surface (the canard), installed in front of the main wing, must be carefully investigated to have a reliable estimate of the aircraft stability and controllability characteristics. This innovative platform provides for a rear engine installation at the tip of the horizontal tailplane. Thus, a specific experimental campaign has been dedicated to investigating the aircraft aerodynamic characteristics in power on conditions

The Potential of Structural Batteries for Commuter Aircraft Hybridization

Electric or hybrid electric propulsion systems have received a great deal of attention in recent years in various branches of transportation including aviation. Europe is committed to the ambitious goals of reducing CO2 emissions by 75%, NOx emissions by 90% and perceived noise by two-thirds by the year 2050 compared to the average new aircraft of the year 2000. The main barrier of the electric propulsion is bound to the battery limits in terms of energy and power densities, thus determining a relevant negative impact on payload or aircraft size. It is possible to design and fly an electrically propelled aircraft, as testified by some existing examples, both prototypical and production models, in the categories of ultralight and general aviation aircraft. A novel technology, which allows the electrification process toward heavier categories of aircraft, is constituted by structural batteries. These are similar in structure to carbon fiber composites, where the matrix features dielectric characteristics, making the structure capable of storing electric energy while retaining the capability to withstand mechanical loads. Despite that, it raises relevant issues concerning aircraft sizing procedures that need to be conceived considering the specific character- istics of such multifunctional technology. This research work aims to evaluate the potential benefits the structural batteries have on the fuel burn for a 11-seater commuter aircraft. According to the envisaged technologies (structural batteries), this work will focus on the determination of the best hybridization factors determining the energy requirements for the typical mission of a commuter aircraft

Aeroelastic wind tunnel tests of the RIBES wing model

Aeroelastic wind tunnel tests on a half-wing model have been performed at the University of Naples “Federico II” to acquire data about aerodynamic forces, section pressure coefficient, stress, strain, and model displacement, to validate high fidelity Fluid-Structure Interaction approaches based on Reynolds-Averaged Navier-Stokes and Finite Element Method solutions investigated at the University of Rome “Tor Vergata”. Most of the available experimental databases of aeroelastic measurements, performed on aircraft wings, model full scale systems, focusing primarily on aerodynamic aspects rather than on structural similitudes. To investigate flow regimes that replicate realistic operating conditions, wind tunnel test campaigns involve the generation of relative high loads on models whose safe dimensioning force the adoption of structural configurations that lose any similitude with typical wing box topologies. The objective of this work is to generate a database of loads, pressure, stress, and deformation measurements that is significant for a realistic aeronautical design problem. At this aim, a wind tunnel model of a half-wing that replicates a typical metallic wing box structure and instrumented with pressure taps and strain gages has been investigated. All experimental data and numerical models are freely available to the scientific community at the website www.ribes-project.eu

Understanding the nature of metal-graphene contacts: A theoretical and experimental study

http://www.gianlucafiori.org/articles/IEDM_2015_Contacts.pdfIn this paper we propose a theoretical and experimental study of the nature of metal-graphene contacts. We use ab-initio simulations and semi-analytical modeling to derive and validate a simple two-parameter model of metal-graphene contacts. Such findings are supported by experimental results for large samples of different types of metal-graphene contacts

Parametric approach to operating costs estimation for an innovative regional aircraft

The focus of the present paper is the evaluation of the operating cost of innovative regional aircraft. The paper proposes a parametric cost model for the assessment of both Direct Operating Cost (DOC) and Indirect Operating Cost (IOC). The present work is carried out in the framework of the Clean Sky II (CS-2) research program, in the Regional IADP IRON project, which deals with the development of an innovative regional aircraft. In particular, the methodology proposed is derived from already existing cost models and it is properly modified in order to be sensitive to innovative technologies and new subsystems configurations in compliance with the Clean Sky II requirements. Finally, the model is applied to the IRON reference aircraft to estimate the possible reduction of its operating cost due to new technologies implemented

Sistema per la sanificazione automatizzata di contenitori per campioni biologici e suo procedimento di utilizzo

Viene descritto un sistema per la sanificazione automatizzata di contenitori per campioni biologici comprendente mezzi di alloggiamento per contenitori per campioni biologici, un percorso di sanificazione avente un’apertura di entrata e un’apertura di uscita, mezzi di movimentazione di detti mezzi di alloggiamento, atti a convogliare i contenitori per campioni biologici lungo detto percorso di sanificazione, una camera di sanificazione e mezzi di asciugatura di contenitori per campioni biologici; viene descritto altresì un procedimento facente uso del sistema della tipologia sopramenzionata