Luca Boggero

Automated Selection of the Optimal On-board Systems Architecture within MDO Collaborative Environment

The on-board systems are having even more importance in aircraft design since the continuous research for a competitive, more optimized and less costly aircraft. In addition, the introduction of new technologies related to the More Electric Aircraft and All Electric Aircraft concepts have raised the interest on on-board systems discipline giving the option of analyzing different architectures. The present paper would enhance the selection of the best on-board systems architecture introducing a new workflow, which is able to identify the best architecture in terms of procurement and operating cost. Since the importance of fuel required providing the secondary power, the effect of each specific architecture on engine performance is particularly considered including a detailed engine module. The workflow is implemented in Optimus framework within a collaborative and multidisciplinary environment and it is open to be integrated with additional modules increasing the fidelity of the analysis. To explore the capability of the defined workflow, the H2020 AGILE regional jet is identified as test case.

Assessment of airframe-subsystems synergy on overall aircraft performance in a Collaborative Design

A Collaborative and Distributed Multidisciplinary Design Optimization (MDO) methodology is presented, which uses physics based analysis to evaluate the correlations between the airframe design and its sub-systems integration from the early design process, and to exploit the synergies within a simultaneous optimization process. Further, the disciplinary analysis modules involved in the optimization task are located in different organization. Hence, the Airframe and Subsystem design tools are integrated within a distributed overall aircraft synthesis process. The collaborative design process is implemented by making use of DLRs engineering framework RCE. XML based central data format CPACS is the basis of communication to exchange model information between the analysis modules and between the partner organizations involved in the research activity. As a use case to evaluate the presented collaborative design method, an unmanned Medium Altitude Long Endurance (MALE) configuration is selected. More electric sub-systems combinations based on the mission requirements are considered. The deployed framework simultaneously optimizes the airframe along with the sub-systems. DLRs preliminary aircraft design environment is used for the airframe synthesis, and the Sub-systems design is performed by the ASTRID tool developed by Politecnico di Torino. The resulting aircraft and systems characteristics are used to assess the mission performance and optimization. In order to evaluate the physics based framework and system-airframe synergies, three case studies are considered: a) Subsystem Architectures effect on overall aircraft performance for a given mission and fixed airframe. b) Effects of variation of mission scenario on aircraft performance for a chosen subsystem architecture and fixed airframe. c) Optimization involving wing planform variables and subsystem architecture for a given mission.

Development of a new conceptual design methodology for parallel hybrid aircraft

In this paper, an innovative methodology for the conceptual design of hybrid-powered airplanes is proposed. In particular, this work focuses on parallel hybrid architectures, in which the thermal engine is mechanically coupled to an electric motor, both supplying propulsive power during a limited number of flight phases, e.g. during takeoff and climb. This innovative solution is the subject of several studies being carried out since the current decade. In this paper, a brief overview of the works conducted by other researchers is provided. Then, an overall aircraft design methodology is proposed, which is derived from the most renewed design algorithms. The original contribution of this work is represented by the development of a methodology for the design of hybrid propulsion systems. Moreover, the proposed method is integrated within a global aircraft design methodology. In particular, several effects of the innovative system on the entire aircraft are considered, for instance the variation of the empty mass or the impacts on fuel consumption. The paper ends with some case studies of the proposed design methodology, and a discussion of the obtained results is provided.

Trade off studies of hybrid-electric aircraft by Fuzzy logic methodology

In this paper, an innovative methodology for the conceptual design of hybrid-electric powered aircraft is proposed. The main idea is the optimization of the designed airplane through the negotiation and settling down of the high-level requirements. This optimization problem is multiobjective, as the goal is the minimization of the fuel and maximum takeoff weight, the time reduction of the climb phase and the enhancement of the safety level during takeoff. The safety level is evaluated as the minimum altitude reached during the climb soon after the takeoff at which the aircraft is able to succeed in an emergency landing in case an engine failure occurs. In order to fulfil these objectives, the three Top Level Aircraft Requirements (TLARs) are relaxed. In more details, the payload and the range - i.e. the maximum distance flown by the airplane - are reduced, while the takeoff run distance (namely the takeoff field length) is increased. A one more design variable is considered, the hybridization degree, meant as the ratio between the electric power and the total propulsive power. The proposed design and optimization methodology is based on the Fuzzy Logic approach. For each objective function, a fuzzy set is defined. The fuzzy sets fix the boundaries of acceptable resulting objectives included between a minimum and a maximum value. The consideration of all the fuzzy sets identifies the optimal solution, which is characterized by the maximum customers satisfaction degree. An Overall Aircraft Design (OAD) environment is set up, in which a deterministic optimizer and fuzzy rules are implemented. The design and optimization problem is analysed and the optimal solution is obtained. The results demonstrate that the optimal solution is achieved by a hybrid airplane. Furthermore, the negotiation of the three requirements entails an improvement of the customers satisfaction.