Time filter

Source Type

Kugler M.E.,TU Munich | Kugler M.E.,System Dynamics | Randt N.P.,TU Munich | Randt N.P.,Institute of Aircraft Design
15th AIAA Aviation Technology, Integration, and Operations Conference | Year: 2015

In the context of an increasing congestion of air traffic flows worldwide, a high-capacity turboprop transport aircraft was designed at the Institute of Aircraft Design of Technical University of Munich that is specifically aimed at serving short- and mid-range routes. Within the scope of research on the concept, this paper presents a parametric aircraft design tool that was created at the institute to support comprehensive analyses and design iterations of large turboprop aircraft. Through a modular approach, the tool covers a broad range of design-related disciplines including aerodynamics, mass prediction, and propulsion and performance modeling. The tool was employed to examine the institute’s turboprop concept. It revealed critical design features and drivers of the concept. During multiple design loops, parameter variations were carried out, and the aircraft was redesigned until the top-level aircraft requirements and certification constraints were met. Finally, mission performance and fuel efficiency of the revised concept were evaluated with the tool. © 2015, American Institute of Aeronautics and Astronautics Inc.


Gnadinger F.,Institute of Aircraft Design | Karcher M.,Fraunhofer Institute for Chemical Technology | Karcher M.,Karlsruhe Institute of Technology | Henning F.,Fraunhofer Institute for Chemical Technology | And 2 more authors.
Applied Composite Materials | Year: 2014

The present paper elaborates a holistic and consistent design process for 2D braided composites in conjunction with Resin Transfer Moulding (RTM). These technologies allow a cost-effective production of composites due to their high degree of automation. Literature can be found that deals with specific tasks of the respective technologies but there is no work available that embraces the complete process chain. Therefore, an overall design process is developed within the present paper. It is based on a correlated conduction of sub-design processes for the braided preform, RTM-injection, mandrel plus mould and manufacturing. For each sub-process both, individual tasks and reasonable methods to accomplish them are presented. The information flow within the design process is specified and interdependences are illustrated. Composite designers will be equipped with an efficient set of tools because the respective methods regard the complexity of the part. The design process is applied for a demonstrator in a case study. The individual sub-design processes are accomplished exemplarily to judge about the feasibility of the presented work. For validation reasons, predicted braiding angles and fibre volume fractions are compared with measured ones and a filling and curing simulation based on PAM-RTM is checked against mould filling studies. Tool concepts for a RTM mould and mandrels that realise undercuts are tested. The individual process parameters for manufacturing are derived from previous design steps. Furthermore, the compatibility of the chosen fibre and matrix system is investigated based on pictures of a scanning electron microscope (SEM). The annual production volume of the demonstrator part is estimated based on these findings. © 2014 Springer Science+Business Media Dordrecht.


Chen H.,Utah State University | Chen H.,State University of New York at Buffalo | Yu W.,Utah State University | Capellaro M.,University of Stuttgart | Capellaro M.,Institute of Aircraft Design
ASME International Mechanical Engineering Congress and Exposition, Proceedings | Year: 2010

Several computer tools are critically assessed for calculating the inertial and structural properties of wind turbine blades. The theoretical foundation of each tool is briefly summarized and the advantages and disadvantages of each tool are pointed out. Several benchmark examples are used to evaluate the performance of different tools. Such a systematic and critical assessment provides guidance for wind turbine blade engineers to choose the right tool for effective design and analysis of wind turbine blades. Copyright © 2010 by ASME.


Randt N.P.,TU Munich | Randt N.P.,Institute of Aircraft Design | Jessberger C.,Bauhaus Luftfahrt eV | Ploetner K.O.,Bauhaus Luftfahrt eV
15th AIAA Aviation Technology, Integration, and Operations Conference | Year: 2015

In the face of global climate change and steadily increasing energy prices, various private and public stakeholders of the commercial aviation industry have proclaimed ambitious goals aimed at reducing the global fuel consumption and thus mitigating the future environmental impact of aviation. From today’s viewpoint, these goals can only be reached if substantial technological progress is achieved in the various fields of air transportation. Here, the progress in aircraft technologies represents one major enabler. Estimating the impact of nextgeneration aircraft types on the future fuel demand of the global commercial air transport fleet, and analyzing the remaining carbon-emissions reduction gap relative to aviation’s climate goals, are the objectives of this paper. To handle the uncertainty about the future technological progress that affects the global fleet performance, multiple technologyimprovement scenarios are investigated. A numerical model of the global air transport fleet is employed to quantify the fleet-wide fuel demand and carbon-emissions reduction impact and conduct sensitivity analyses. The results obtained clearly indicate that the climate goals of the mid-term future cannot be reached solely by integrating next-generation aircraft types into the fleet. Further measures such as the use of biofuels will equally be required. © 2015, American Institute of Aeronautics and Astronautics Inc.


Strobl T.,Airbus | Storm S.,Airbus | Thompson D.,Mississippi State University | Hornung M.,TU Munich | And 3 more authors.
Journal of Aircraft | Year: 2015

Akey design factor impacting the use of electrical power to drive aircraft systems and subsystems is energy efficiency. With the design of an all-electric, hybrid ice protection system, energy consumption can be reduced to a large extent. The hybridization is achieved through an intentional partitioning of the ice at the stagnation line by melting via surface heating and ice shedding in the unheated regions of the airfoil surface via an electromechanical deicing systembased on piezoelectric multilayer actuators. To further reduce energy consumption, the adhesion forces between the ice and the airfoil surface can be reduced using an ultrasmooth,nanostructured surfacewithwater-and ice-repellent properties that encourages ice shedding. Experimental investigations, performed in a laboratory-scale icing wind tunnel for a smallscale configuration, reveal that the hybrid approach for ice protection reliably sheds the ice accreted on the airfoil surface.Comparedwith an all-thermoelectric systemfor ice protection investigated in the same icingwind tunnel facility using identical test conditions, the hybrid approachwas demonstrated to reduce power consumption up to 91%. Beyond the laboratory tests, numerical simulations of the hybrid strategy analogous to the one used for the experiments are performed. The time history of the residual ice shapes aft of the heated region is simulated using the ice accretion prediction software LEWICE2D for a wet-running anti-icing subsystem. Finite element analyses of the effects of the piezoelectric actuators are then performed using Abaqus to investigate the ice-shedding capability in the unheated regions of the airfoil surface. The numerical results show that the variation in the different ice shapes affects the stiffness of themodel. It becomes obvious that the critical threshold for ice shedding, that is, the stiffness that determineswhether residual ice delaminates fromthe airfoil surface, is affected to aminor extent by the interfacial area and predominantly by the thickness of the ice layer. Further, the simulation results correlate well with experimental results obtained in the icing wind tunnel. It can be concluded that reliable operation of the hybrid system for ice shedding can be guaranteed when using a harmonic sweep excitation able to excite the structure at its resonance. © 2014 by Benoit Malouin.


Stens C.,Institute of Aircraft Design | Middendorf P.,Institute of Aircraft Design
International Journal of Fatigue | Year: 2015

Abstract Fatigue of composite structures is a complex process involving several types of failure. Existing approaches either neglect this complexity or require large computational effort. In this work, a simple progressive damage model including strength and stiffness degradation is implemented into finite element (FE) software. To reduce computational time, the major part of stress calculations is carried out by classical lamination theory. At single points of time, FE analysis is employed to support these calculations. The simplified model is tested against a reference model using FEA after each load cycle. Calculations are set up for a tensile specimen and a cap profile with quasi-isotropic layup. The simplified model using CLT is shown to be in good agreement with the reference while significantly reducing computational time. © 2015 Elsevier Ltd.


Liu J.,Northwestern Polytechnical University | Li Y.,Northwestern Polytechnical University | Guo W.,Northwestern Polytechnical University | Shi X.,Northwestern Polytechnical University | And 2 more authors.
Hangkong Xuebao/Acta Aeronautica et Astronautica Sinica | Year: 2011

In order to obtain the mechanical parameters of the bird during the process of bird striking, numerical simulations and experiments of bird striking on plate are studied in the paper. The bird mass is 1.8 kg and 3.6 kg respectively, and the plate is made by LY12 aluminium alloy with the thickness of 10 mm and 14 mm and 45# steel with the thickness of 4.5 mm and 8.0 mm. Sixteen groups of experiments are performed in the present paper with the bird velocity at 70, 120, 170 m/s, respectively. The histories of displacement-time and strain-time of plate as well as the force-time are measured by the dynamic data acquisition system, and the whole process of dynamic response during bird striking on plate is recorded by high-speed camera system. The results of the experiments indicate that the repeatability of the impacting velocities and the measured results for twice experiments in one group are very good. The reaction time of bird striking is millisecond, so its behavior belongs to impact dynamics; there exists strong coupling between the bird and the plate. The deformation of the plate is very big and the ratio of the plate displacement at the center point to the plate thickness is 7.9. The fluid behavior of the bird is obvious with the increment of the impacting velocity.

Loading Institute of Aircraft Design collaborators
Loading Institute of Aircraft Design collaborators