1,720,983 research outputs found
NeoCASS: an Integrated Tool for Structural Sizing, Aeroelastic Analysis and MDO at Conceptual Design Level
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Aeroelastic Analysis of a Regional Aircraft with Active Camber Morphing Device
No full textStarting from the previous activities developed by Politenico di Milano in the framework of FP7-NOVEMOR, this paper reports the aeroelastic assessment carried out on the so-called Reference Aircraft to validate the proposed morphing concepts. Indeed, in the case of morphing devices based on compliant structures like ones here proposed, the aeroelastic assessment is fundamental to verify the reliability of the proposed morphing solutions. After a reminder on the tools developed aiming at the design of variable camber morphing wings, the paper describes the main aeroelastic results obtained from the application of the morphing concepts based on compliant structures to a typical regional aircraft
PyPAD: a Multidisciplinary Framework for Preliminary Airframe Design
No full textThe preliminary design of an aircraft is a complex task involving a lot of different disciplines and it is becoming more challenging in the future due to the reduced budget and compressed time. At the same time new projects present new technical challenges due to the request for highly demanding performances, in order to reduce the fuel consumption (cost and environment impact) and to increase the payload. The preliminary design problem involves different disciplines, like: Aerodynamics, Controls, Regulations, Performances, Systems Definition, Design, Loads & Aeroelasticity, Structural Sizing, etc.. The present work focuses on the development of an integrated framework suitable for preliminary airframe design, called PyPAD (Python module for Preliminary Aircraft Design). The modules developed until now allow for the definition of multi fidelity aero-structural models starting from a CPACS input file and to compute static loads (trim) and flutter margin with the minimum effort by the user. Moreover PyPAD is able to compute the dynamic response under all the different load conditions, including discrete and continuous gust, nodal forces, command inputs. The tool is also able to export the state-space aeroelastic models tacking advantage of the modern state space model realization. In this way all the loads prescribed by the regulations can be computed in a fully automatic approach. A complete test case, starting from the CPACS input and ending with the definition of structural, aerodynamic and aeroelastic models and with the computation of different design loads is reported
PyPAD: a Multidisciplinary Framework for Preliminary Airframe Design
Full text linkPurpose: The purpose of this paper is to describe the development of an integrated framework suitable for preliminary airframe design, called PyPAD (Python module for Preliminary Aircraft Design), providing the capability to define models to compute loads and to perform the structural sizing. Design/methodology/approach: The modules developed until now allow for the definition of multi-fidelity aero-structural models starting from a Common Parametric Aircraft Configuration Schema (CPACS) input file and to compute static loads (trim) and flutter margin with minimum user effort. PyPAD take advantages of Abaqus-CAE, and the main functions are developed in Python, to take advantages of the simplicity in terms of software development and maintenance, but the core routines are developed in Fortran, taking advantages of parallel programming to get the best performances. Findings: A complete test case, starting from the CPACS input and ending with the definition of structural, aerodynamic and aero-elastic models, with the computation of different design loads, is reported. An example will show that the framework developed is able to handle different problematics of the preliminary projects using quite complex global models. Practical implications: All the tools developed in the framework, and the ones currently under development, could be a valid help during the preliminary design of a new aircraft, speeding up the iterative process and improving the design solution. Originality/value: PyPAD is the first framework developed around Abaqus-CAE for the preliminary aircraft design and is one of the few tools looking at the different problematics involved in a preliminary airframe design: design, loads and aero-elasticity, sizing and multi-disciplinary optimization
NeoCASS: An integrated tool for structural sizing, aeroelastic analysis and MDO at Conceptual Design Level
No full textThis paper presents a design framework called NeoCASS (Next generation Conceptual Aero-Structural Sizing Suite), developed at the Department of Aerospace Engineering of Politecnico di Milano in the frame of SimSAC (Simulating Aircraft Stability And Control Characteristics for Use in Conceptual Design) project, funded by EU in the context of 6th Framework Program. It enables the creation of efficient low-order, medium fidelity models particularly suitable for structural sizing, aeroelastic analysis and optimization at the conceptual design level. The whole methodology is based on the integration of geometry construction, aerodynamic and structural analysis codes that combine depictive, computational, analytical, and semi-empirical methods, validated in an aircraft design environment. The work here presented aims at including the airframe and its effect from the very beginning of the conceptual design. This aspect is usually not considered in this early phase. In most cases, very simplified formulas and datasheets are adopted, which implies a low level of detail and a poor accuracy. Through NeoCASS, a preliminar distribution of stiffness and inertias can be determined, given the initial layout. The adoption of empirical formulas is reduced to the minimum in favor of simple numerical methods. This allows to consider the aeroelastic behavior and performances, as well, improving the accuracy of the design tools during the iterative steps and lowering the development costs and reducing the time to market. The result achieved is a design tool based on computational methods for the aero-structural analysis and Multi-Disciplinary Optimization (MDO) of aircraft layouts at the conceptual design stage. A complete case study regarding the TransoniCRuiser aircraft, including validation of the results obtained using industrial standard tools like MSC/NASTRAN and a CFD (Computational Fluid Dynamics) code, is reported. As it will be shown, it is possible to improve the degree of fidelity of the conceptual design process by including tailored numerical tools, overcoming the lacks of statistical methods. The result is a method minimally dependent on datasheets, featuring a good compromise between accuracy and costs
Introduction and application of PyPAD, a framework for multidisciplinary airframe design
No full textThe preliminary design of an aircraft is a complex task involving a lot of different disciplines and it is becoming more challenging in the future due to the reduced budget and compressed time. At the same time new projects present new technical challenges due to the request for highly demanding performances, in order to reduce the fuel consumption (cost and environment impact) and to increase the payload. The preliminary design problem involves different disciplines, like: Aerodynamics, Controls, Regulations, Performances, Systems Definition, Design, Loads & Aeroelasticity, Structural Sizing, etc.. The present work focuses on the development of an integrated framework suitable for preliminary airframe design, called PyPAD (Python module for Preliminary Aircraft Design). The modules developed until now allow for the definition of multi fidelity aero-structural models starting from a CPACS input file and to compute static loads (trim) and utter margin with the minimum effort by the user. Moreover PyPAD is able to compute the dynamic response under all the different load conditions, including discrete and continuous gust, nodal forces, command inputs. The tool is also able to export the state-space aeroelastic models tacking advantage of the modern state space model realization. In this way all the loads prescribed by the regulations can be computed in a fully automatic approach. A complete test case, starting from the CPACS input and ending with the definition of structural, aerodynamic and aeroelastic models and with the computation of different design loads is reported
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
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