Pier Davide Ciampa

Methodological enhancements in MDO process investigated in the AGILE European project

This paper presents methodological investigations performed in research activities in the field of MDO in overall aircraft design in the ongoing EU funded research project AGILE. AGILE is developing the next generation of aircraft Multidisciplinary Design and Optimization processes, which targets significant reductions in aircraft development costs and time to market, leading to cheaper and greener aircraft solutions. The paper introduces the AGILE project structure and describes the achievements of the 1st year (Design Campaign 1) leading to a reference distributed MDO system. A focus is then made on the different novel optimization techniques studied during the 2nd year, all willing to ease the optimization of complex workflows, characterized by high degree of discipline interdependencies, high number of design variables in the context of ∗Research Engineer, Information Processing and Systems Department, AIAA Member. †Post Doctoral Researcher, System Design and Performance evaluation Department ‡Research Engineer, Research and Innovation §Assistant Professor, Department of Industrial Engineering (DII), AIAA member ¶Professor, Department of Industrial Engineering (DII), AIAA member ‖Research engineer, Integrated Aircraft Design Department, AIAA member ∗∗Researcher, Propulsion Systems Aerodynamics Department

A Hierarchical Aeroelastic Engine for the Preliminary Design and Optimization of the Flexible Aircraft

The work introduces the Aeroelastic Engine, a module under development at DLR to support physics-based modeling and analysis of the complete flexible aircraft for preliminary multidisciplinary design optimization (MDO) applications in a collaborative environment. The paper presents the implemented structural modeling, the analysis capabilities, and the coupling schemas to account for the fluid structure interactions. The structural representation provided by the module is based on a set of hierarchical Finite Element (FE) formulation. The implemented fluid-structure-interactions kernel is tailored for loosely coupled analysis, and is based on radial basis functions (RBF). Heterogeneous physics based analysis modules are orchestrated by an engineering environment based on the DLR’s central data model CPACS, and on the distributed framework RCE. Hence, the impact of the flexibility effects in pre-design are assessed for the aero-structurally coupled design of a medium-haul reference aircraft.

Aeroelastic Design and Optimization of Unconventional Aircraft Configurations in a Distributed Design Environment

A Multidisciplinary Design and Optimization (MDO) methodology is presented, which uses a physics-based modeling approach for the preliminary structural design of unconventional aircraft configurations. Therein, static as well as dynamic aeroelastic stability constraints are accounted for at the early stage of the design process. A functional parametrization is applied for the description of the aircraft’s geometry. Several physics based analysis modules are orchestrated by an engineering framework to enable distributed multidisciplinary analysis and optimization. The method builds on DLR’s collaborative design environment, which uses the central data model CPACS to provide consistent model information in the analysis workflow. A knowledge based aeroelastic engine is developed to accelerate the integration of the disciplinary models and the subsequent aeroelastic analysis, and to automate the disciplinary couplings. The approach is tested in optimization test cases for a conventional wing design as well as for a Blended Wing Body configuration.

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.

A Collaborative MDO Approach for the Flexible Aircraft

An aero-structurally coupled MDO workflow for preliminary aircraft design is presented. Built on a multifidelity approach, it integrates analysis modules for conceptual aircraft design as well as physics-based methods for a more accurate and detailed aircraft synthesis. To account for aeroelastic effects already in the early design phases, the recently developed Aeroelastic Engine is implemented. DLR’s collaborative design environment, which utilizes distributed network analysis modules as well as the unified data format CPACS for the transdisciplinary coupling between disparate modules, serves as the foundation of the workflow. The multifidelity approach in the formulation of this collaborative environment and its main building blocks are briefly explained, whereas the working principles of the workflow to analyze the impact of flexibility effects of the aircraft are discussed thoroughly. As in such distributed computing approach the modules do not share a common memory, several modifications to the file-handling of CPACS were required, which then allowed for nested convergence loops to obtain the aeroelastic equilibrium for multiple sizing load cases. The impact of aeroelastic effects on wing sizing and on flight performance are presented in an example analysis problem for a mediumhaul aircraft equipped with a high aspect ratio wing.

Advanced turboprop multidisciplinary design and optimization within AGILE project

The present paper deals with the design, analysis and optimization of a 90 passengers turboprop aircraft with a design range of 1200 nautical miles and a cruise Mach number equal to 0.56. The pres cribed aircraft is one of the use cases of the AGILE European project, aiming to provide a 3rd generation of multidisciplinary design and optimization chain, following the collaborative and remote aircraft design paradigm, through an heterogenous team of experts. The multidisciplinary aircraft design analysis is set-up involving tools provided by AGILE partners distributed worldwide and run locally from partners side. A complete design of experiment, focused on wing planform variables, is performed to build response surfaces suitable for optimization purposes. The goal of the optimization is the direct operati ng cost , subject to wing design variables and top - level aircraft requirements.

AGILE the Next Generation of Collaborative MDO: Achievements and Open Challenges

The EU funded AGILE project is developing the next generation of aircraft Multidisciplinary Design and Optimization processes, which target significant reductions in aircraft development costs and time to market, leading to more cost-effective and greener aircraft solutions. 19 industry, research and academia partners from Europe, Canada and Russia are developing solutions to cope with the challenges of collaborative design and optimization of complex products. In order to accelerate the deployment of large-scale, collaborative multidisciplinary design and optimization (MDO), a novel methodology, the so-called AGILE Paradigm, has been developed. The AGILE Paradigm is a “blueprint for MDO”, guiding the deployment and the execution of collaborative “MDO systems” for complex products practiced by cross-organizational design teams, distributed multi-site, and with heterogeneous expertise. A set of technologies has been developed by the AGILE consortium in order to enable the implementation of the AGILE Paradigm, and to support the design and the optimization of novel aircraft configurations. The AGILE Paradigm ambition is reduce the lead time of 40% with respect to the current state-of-the-art. This paper addresses the MDO challenges tackled by the AGILE Paradigm. An overview of the main AGILE Paradigm’s underlying architecture is described. The paper presents a preliminary assessment of the AGILE Paradigm application, and provides an overview of the main achievements enabled by its implementation for the solution of selected aircraft design and optimization use cases. The paper concludes with an overview of the challenges still open and an outlook of the AGILE Paradigm.

A clustered and surrogate-based MDA use case for MDO scenarios in AGILE project

In this paper methodological investigations regarding an innovative Multidisciplinary Design and Optimization (MDO) approach for conceptual aircraft design are presented. These research activities are part of the ongoing EU-funded research project AGILE. The next generation of aircraft MDO processes is developed in AGILE, which targets significant reductions in aircraft development cost and time to market, leading to cheaper and greener aircraft solutions. The paper introduces the AGILE project structure and recalls the achievements of the first year of activities where a reference distributed MDO system has been formulated, deployed and applied to the design and optimization of a reference conventional aircraft configuration. Then, investigations conducted in the second year are presented, all aiming at making the complex optimization workflows easier to handle, characterized by a high degree of discipline interdependencies, multi-level processes and multi-partner collaborative engineering activities. The paper focuses on an innovative approach in which knowledge-based engineering and collaborative engineering techniques are used to handle a complex aircraft design workflow. Surrogate models replacing clusters of analysis disciplines have been developed and applied to make workflow execution more efficient. The paper details the different steps of the developed approach to set up and operate this test case, involving a team of aircraft design and surrogate modelling specialists, and taking advantage of the AGILE MDO framework. To validate the approach, different executable workflows were generated automatically and used to efficiently compare different MDO formulations. The use of surrogate models for clusters of design competences have been proved to be efficient approach not only to decrease the computational time but also to benchmark different MDO formulations on a complex optimization problem.

MDO Framework for university research collaboration : AGILE Academy Initiatives & Outcomes

AGILE Project is developing the 3rd generation MDO processes, which will support the development of the next generation aerospace products. The establishment of effective collaborative design methodologies, is currently acknowledged as the key enabler for future product development processes. At the same time, the need to introduce collaborative design techniques within educational activities is also well recognized by the Academic, Research and Industrial communities. AGILE project supported by European Commission’s H2020 Programme, is setting the “AGILE Paradigm”, a conceptual framework which contains all the elements to implement a multidisciplinary collaborative design network. The AGILE Academy initiative is conceived to infuse into the Academic organizations and educational environments the “AGILE Paradigm”, and make available all the technologies developed within the AGILE Project, which support the implementation of such a Paradigm. This paper focus is on the inception, approach and results of the AGILE Academy participants from several universities around the world.

Aerostructural Interaction in a Collaborative MDO Environment

The work presents an approach for aircraft design and optimization, developed to account for fluid-structure interactions in MDO applications. The approach makes use of a collaborative distributed design environment, and focuses on the influence of multiple physics based aerostructural models, on the overall aircraft synthesis and optimization. The approach is tested for the design of large transportation aircraft.