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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 accoun...
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... reference platform considered for the analysis is a regional 90-passenger jet aircraft. Its characteristics are summarized in Table 1. Two "retrofitting packages" are considered: • High BPR-geared turbofan engine installation, leading to improvements in fuel consumption, noise, emissions and maintenance costs. ...Context 2
... Table 10, a list of the equipment taken into consideration for all the retrofitting solutions is represented. As already described, two different engine architectures are analyzed: a conventional engine with BP R = 5.4 and advanced geared turbofan engines with a higher BPR (9.0 < BPR < 15). ...Context 3
... as input, the total aircraft and the system weight breakdown, the methodology can compute the OBS costs. In this way, three different unit prices can be considered for the MEA1, MEA2 and AEA architecture, as indicated in Table 10. Aerospace 2022, 9, x FOR PEER REVIEW different unit prices can be considered for the MEA1, MEA2 and AEA archite indicated in Error! ...Context 4
... the total development, co and equipment costs required to perform seven different refortifying activities. In Table 11 summarizes the total development, conversion and equipment costs required to perform seven different refortifying activities. In case the operation includes an engine upgrade; the turbofan BPR that is considered is 15. ...Context 5
... particular, the AGILE 4.0 collaborative MDO environment allowed us to highlight the impact of a complex retrofitting activity on a regional jet aircraft. In Table 12, all the hypotheses that were assumed to perform the trade-off analysis are summarized. According to the scenario, the retrofitted aircraft will operate for twelve years or more, during which time it will complete seven flights per day for almost every day of the year. ...Context 6
... than their performance, capital costs relating to the development of all the retrofitting activities that are considered in the DOE are computed. Table 13 shows the values computed for a single year of aircraft operation for three different fleets. The system under analysis is the same as that considered in the previous section, a retrofitted aircraft with a BPR 15 engine and AEA OBS architecture. ...Context 7
... on our results and the data previously illustrated, it is possible to compute and compare all the savings generated by a particular retrofitting activity. Table 14 shows the total amount in million EUR saved in a single year per aircraft as a consequence of the three aircraft retrofitting activities performed on a given fleet. In this case, different fleet sizes are not computed since the number of aircraft retrofitted does not influence the savings made in a year. ...Context 8
... savings are computed according to the data provided by Embraer with respect to the E2 Family costs [5]. Table 12 shows all the hypotheses that are assumed to compute the presented calculation. The system under analysis is the same as that considered in the previous section, a retrofitted aircraft with a BPR 15 engine and AEA OBS architecture. ...Context 9
... is mainly due to the reduced improvement in fuel consumption and emissions performance. Table 15 illustrates the difference between capital costs and savings per year per aircraft, obtained for three different fleets and retrofit solutions. The data for the BPR 15 and AEA architecture are also shown. ...Context 10
... data for the BPR 15 and AEA architecture are also shown. The values indicated in this table are the difference between capital costs, illustrated in Table 13, and savings, shown in Table 14. As it is possible to imagine, the solution is more convenient if the number of retrofitted aircraft is increased. ...Context 11
... data for the BPR 15 and AEA architecture are also shown. The values indicated in this table are the difference between capital costs, illustrated in Table 13, and savings, shown in Table 14. As it is possible to imagine, the solution is more convenient if the number of retrofitted aircraft is increased. ...Citations
... Retrofit studies have been performed on various propulsion system designs including battery-hybrid [5,6], pure FC-electric or pure hydrogen combustion (both [7]), or conventional engine replacement [8], and have also been assessed in terms of costs [9]. Hydrogen produced from renewable energy is seen as one of the key enablers of the commercial aviation sector transition to climate neutrality, with an estimated global hydrogen aircraft market value of $23.71 billion in 2030 already and a projection to reach $144.53 billion by 2040 [10]. ...
A wide range of aircraft propulsion technologies is being investigated in current research to reduce the environmental impact of commercial aviation. As the implementation of purely hydrogen-powered aircraft may encounter various challenges on the airport and vehicle side, combined hydrogen and kerosene energy sources may act as an enabler for the first operations with liquid hydrogen propulsion technologies. The presented studies describe the conceptual design of such a dual-fuel regional aircraft featuring a retrofit derived from the D328eco under development by Deutsche Aircraft. By electrically assisting the sustainable aviation fuel (SAF) burning conventional turboprop engines with the power of high-temperature polymer-electrolyte fuel cells, the powertrain architecture enables a reduction of SAF consumption. All aircraft were modeled and investigated using the Bauhaus Luftfahrt Aircraft Design Environment. A description of this design platform and the incorporated methods to model the hydrogen-hybrid powertrain is given. Special emphasis was laid on the implications of the hydrogen and SAF dual-fuel system design to be able to assess the potential benefits and drawbacks of various configurations with the required level of detail. Retrofit assumptions were applied, particularly retaining the maximum takeoff mass while reducing payload to account for the propulsion system mass increase. A fuel cell power allocation of 20% led to a substantial 12.9% SAF consumption decrease. Nonetheless, this enhancement necessitated an 18.1% payload reduction, accompanied by a 34.5% increment in propulsion system mass. Various additional studies were performed to assess the influence of the power split. Under the given assumptions, the design of such a retrofit was deemed viable.
... Additionally, it computes cost savings (a component of direct operating costs) resulting from reductions in fuel consumption, maintenance costs, and emission taxes. The cost methodology is explained in [47]. Further details about the MDA workflow presented here can be found in [48]. ...
This work aims at developing new methodologies to optimize computational costly complex systems (e.g., aeronautical engineering systems). The proposed surrogate-based method (often called Bayesian optimization) uses adaptive sampling to promote a trade-off between exploration and exploitation. Our in-house implementation, called SEGOMOE, handles a high number of design variables (continuous, discrete or categorical) and nonlinearities by combining mixtures of experts for the objective and/or the constraints. Additionally, the method handles multi-objective optimization settings, as it allows the construction of accurate Pareto fronts with a minimal number of function evaluations. Different infill criteria have been implemented to handle multiple objectives with or without constraints. The effectiveness of the proposed method was tested on practical aeronautical applications within the context of the European Project AGILE 4.0 and demonstrated favorable results. A first example concerns a retrofitting problem where a comparison between two optimizers have been made. A second example introduces hierarchical variables to deal with architecture system in order to design an aircraft family. The third example increases drastically the number of categorical variables as it combines aircraft design, supply chain and manufacturing process. In this article, we show, on three different realistic problems, various aspects of our optimization codes thanks to the diversity of the treated aircraft problems.
Structural health monitoring represents an interesting enabling technology towards increasing aviation safety and reducing operating costs by unlocking novel maintenance approaches and procedures. However, the benefits of such a technology are limited to maintenance costs reductions by cutting or even eliminating some maintenance scheduled checks. The key limitation to move a step further in exploiting structural health monitoring technology is represented by the regulation imposed in sizing aircraft composite structures. A safety margin of 2.0 is usually applied to estimate the ultimate loading that composite structures must withstand. This limitation is imposed since physical nondestructive inspection of composite structures is really challenging or even impossible in some cases. However, a structural health monitoring system represents a viable way for a real time check for the health status of a composite structure. Thus, the introduction of structural health monitoring should help into reducing the stringent safety margin imposed by aviation regulation for a safe design of composite structures. By assuming a safety margin reduction from 2.0 to 1.75 thanks to the installation of permanently attached sensors for structural health diagnostics, this paper assesses the potential fuel savings and direct operating costs through a multidisciplinary analysis on a A220-like aircraft. According to the foreseen level of technology, addressed through the number of sensors per square meter, a DOC saving from 2% up to 5% is achievable preserving, at the same time, all the key aircraft performance.
