@inproceedings{GrasseltHoeschlerKonstantinidis, author = {Grasselt, David and H{\"o}schler, Klaus and Konstantinidis, Aris}, title = {Fluid Structure Interaction with Inconsistent Software Platforms}, series = {ECCOMAS, Barcelona 2014}, booktitle = {ECCOMAS, Barcelona 2014}, abstract = {The FSI problem class describes the mutual dependence of the multiphysical interaction between aerodynamic forces and structural mechanic deformation. The FSI effects become more significant and influences partially safety analysis when the dependence between the influence and response becomes stronger, e.g. the fluttering of aero-engine blades or the pumping of blood by the ventricles of the human heart. [1] The modelling of fluid dynamic problems requires solutions different from those, which are relevant for structure mechanical issues. The coupling of modern numerical methods and tools enables the analysis of mutual dependencies. Although software companies develop more and more integrated solutions, inconsistent application of software solutions (SW) play an important role. Furthermore, automation of interface processing, finite-element analysis (FEA) and computational fluid dynamic (CFD) solution processes can lead to significant exploitation potential for example for design-optimisation applications, design evaluation with target solver-, Monte Carlo-, six sigma-, Taguchi- and stochastic design improval methods or is capable to just accelerate the design process. This requires the strict separation of method code and application dependent information. The paper describes a coupling approach, in the case of obligatory use of inconsistent SW for the separate, mutual depending challenges of a FSI problem description, especially for strong displacement applications. The first step of a FSI process chain is the solution of a fluid dynamic problem followed by a coupled FE Analysis. The start of the FE solution process can be divided into three steps: • the pre-processing and generation of a finite-element-model input file, • the manipulation with an external code, including the required time and data management, • the execution of the FEM solver with the manipulated input file. Typical finite-element-codes generate an input file and process this file with a SW specific interface. A self-coded Java programme uses this interface strategy to manipulate the structural solvers' input before executing the solver. The outcome of the FE solution can be divided into two types of information. The most obvious is numerical output in form of stress or displacement. Additionally FSI process relevant information is required to allow the coupling of FEA to the CFD analysis: boundary conditions, like surface pressure or heat transfer coefficients distributions provoked deformation of the component. A key method to allow importing deformed surfaces to form the 2nd coupling way is the description of surfaces using non-uniform rational B-splines.}, language = {en} } @inproceedings{GrasseltHoeschler, author = {Grasselt, David and H{\"o}schler, Klaus}, title = {Safety Assessment of Aero Engine Thrust Reverser Actuation Systems : ISABE-2015-20260}, series = {22nd International Symposium on Air Breathing Engines (ISABE-2015-20260), 25.-30. Oktober 2015, Phoenix (AZ, USA)}, booktitle = {22nd International Symposium on Air Breathing Engines (ISABE-2015-20260), 25.-30. Oktober 2015, Phoenix (AZ, USA)}, publisher = {ISABE}, pages = {7}, language = {en} } @inproceedings{GrasseltHoeschler, author = {Grasselt, David and H{\"o}schler, Klaus}, title = {Vergleich von FSI Methoden kommerzieller integrativer Programme gegen{\"u}ber inkonsistenten L{\"o}sungen am Beispiel eines Schubumkehrers im Flug-Triebwerk}, series = {Deutscher Luft- und Raumfahrtkongress 2015, 22. -24. September 2015, Rostock}, booktitle = {Deutscher Luft- und Raumfahrtkongress 2015, 22. -24. September 2015, Rostock}, publisher = {Deutsche Gesellschaft f{\"u}r Luft- und Raumfahrt - Lilienthal-Oberth e.V.}, address = {Bonn}, url = {http://nbn-resolving.de/urn:nbn:de:101:1-201512113094}, pages = {7}, language = {de} } @inproceedings{SainHoeschlerMischke, author = {Sain, Chetan Kumar and H{\"o}schler, Klaus and Mischke, Marcel}, title = {Concept study of variable area fan nozzle for UHBPR turbofan engine}, series = {22nd International Symposium on Air Breathing Engines (ISABE-2015-20213), 25.-30. Oktober 2015, Phoenix (AZ, USA)}, booktitle = {22nd International Symposium on Air Breathing Engines (ISABE-2015-20213), 25.-30. Oktober 2015, Phoenix (AZ, USA)}, publisher = {ISABE}, pages = {8}, language = {en} } @inproceedings{SainHoeschler, author = {Sain, Chetan Kumar and H{\"o}schler, Klaus}, title = {Comparative Assessment between Variable Area Fan Nozzle Concepts at Inner and Outer By-Pass Duct Surfaces}, series = {ISABE-2017-21342, 03.-08. September 2017, Manchester (UK)}, booktitle = {ISABE-2017-21342, 03.-08. September 2017, Manchester (UK)}, publisher = {ISABE}, pages = {10}, abstract = {The next generation of civil turbofan engines target the by-pass ratios of up to 20:1, which are far beyond the current levels of 10:1 to 12:1. These jet engines require a significant step forward in low-pressure system technologies. The European Union supports within the 7th Framework the research activities for these new low-pressure systems through the program ENOVAL [1]. Such a new low-pressure technology can be achieved through an innovative fan design with a low fan pressure ratio and a radically increased fan diameter compared to the current conventional turbofan engines. The aerodynamic stability of such large fans is quite likely very sensitive against backpressure variations in the by-pass duct. For this reason, the back-pressure regulation of such a large fan, especially during the take-off operation, can be achieved through the introduction of a Variable Area Fan Nozzle (VAFN). On the given geometry, two potential design spaces were studied and the conceptual designs of two VAFN concepts were created. This paper presents a comparative study between both the concepts following the requirements of different attributes. These involve the performance assessment, structural design study, and a preliminary assessment of the design features for integration into the nacelle or in the core fairing structure. For the comparison, the clean nozzle, without any modulation of the BPD aero lines, was taken as the reference case. The VAFN assessments were carried out on two VAFN positions, over- and under-area, considering the maximum take-off and maximum climb flight conditions respectively. For the selected concepts, CFD trade studies were executed in order to compare the nozzle performance, in which three main governing design parameters i.e. discharge-, thrust performance coefficient, and drag, were examined. This research has received funding from the European Union's 7th Framework Program under grant agreement number 604999.}, language = {en} } @misc{SainHoeschler, author = {Sain, Chetan Kumar and H{\"o}schler, Klaus}, title = {Aerodynamic Assessment of Nozzle Area Variation by Core Fairing Modulation}, series = {CEAS Aeronautical Journal}, volume = {8}, journal = {CEAS Aeronautical Journal}, number = {3}, issn = {1869-5590}, doi = {10.1007/s13272-017-0253-4}, pages = {493 -- 504}, abstract = {Aerodynamic assessment of nozzle area variation by core fairing modulation on the way towards the goals of ACARE 2020 and Flightpath 2050 [1], a next potential step in flight engine technology is to develop engines with by-pass ratios (BPR) far beyond the current levels of 10 to 12. These new engine concepts can have BPRs of up to 20 and require a significant step forward in low pressure system technologies. The European Union supports within the 7th Framework the research activities for these new low pressure systems through the program ENOVAL [2]. Such a new low pressure technology can be achieved through an innovative fan design with a low fan pressure ratio and a radically increased fan diameter compared to the current conventional turbofan engine. The aerodynamic stability of such large fans is most likely very sensitive against backpressure variations. For this reason the backpressure regulation of such large fan, specially during take-off operation, can be achieved through the introduction of a Variable Area Fan Nozzle [VAFN]. This paper describes the aerodynamic study of a particular VAFN concept. This concept offers the variation in fan nozzle throat-area by the displacement of the inner fixed structure (IFS) (also known as core fairing structure). The aim of the assessment was to perform a comparative aerodynamic study at different design configurations. These configurations were derived by varying the design parameters such as the location of section plane (divides the IFS into front and rear block) and the position of the rotational axis. The range of the area change for different flight cases was defined by the engine owner under the ENOVAL program. For each design configuration, the geometries for all the flight cases with their required variation in the nozzle throat area were developed. For the initial study phase the aero assessment a 2D axis-symmetric flow was considered and the airflow from the vent nozzle and core nozzle were included. At this stage, the flight cases with the maximum variation in throat area (e.g. max take-off and top of climb) and the nominal cruise case without area change were studied. Three major performance parameters, the thrust coefficient, nozzle drag coefficient and the after-body drag were calculated. The effects of the gaps and steps (resulting from the overlapping between the IFS segments) on the performance parameters were examined. A comparative result was produced in which the different design parameters of the VAFN were ranked. With the help of few iterations, the best possible design configuration was accessed. At the final stage, the detailed aerodynamic studies on the selected design configuration were performed for the whole range of area variation, including the cruise case with different power loops and the maximum area changes with the variations in the day temperature. [1] Advisory Council for Aviation Research and Innovation in Europe (ACARE) with its targets for CO2 emission- and noise reduction by year 2020 for civil European aircraft industries to be more innovative, sustainable and highly competitive till year 2050 (Flightpath 2050) www.acare4europe.com/. [2] European 7th Framework Program ENOVAL(ENgine mOdule VALidators) http://www.enoval.eu/.}, language = {en} } @inproceedings{KazulaHoeschler, author = {Kazula, Stefan and H{\"o}schler, Klaus}, title = {A Systems Engineering Approach to Variable Intakes for Civil Aviation}, series = {7th European Conference for Aero Nautics and Space Sciences (EUCASS), Milan (Italien), 2017}, booktitle = {7th European Conference for Aero Nautics and Space Sciences (EUCASS), Milan (Italien), 2017}, doi = {10.13009/EUCASS2017-20}, pages = {11}, abstract = {A systems engineering approach to develop variable nacelle intakes for aero engines in civil aviation is presented. The goal of this methodical approach is to find solutions to design problems that can be successfully utilised in aviation without further effort during the certification. By using variable intakes, aircraft and aero engine manufacturers can fulfil their customers' needs for safe, efficient and fast travelling. Therefore, a system shall be installed which is able to modify the nacelle intake contour between two extrema. On the one hand, a sharp thin contour, which produces low drag and allows to fly faster or more efficiently, is optimal during cruise condition. On the other hand, a round thick intake lip is necessary to avoid flow separations with the potential to cause dangerous events during take-off and climb conditions. The utilised systems engineering approach is introduced. The executed steps and methods used for creating and evaluating concept variants for variable intakes are displayed particularly. Those contain the determination and evaluation of requirements and functions, as well as the generation and assessment of concepts. Finally yet importantly, following tasks are presented.}, language = {en} } @misc{GrasseltHoeschlerKazula, author = {Grasselt, David and H{\"o}schler, Klaus and Kazula, Stefan}, title = {A Design Approach for a Coupled Actuator System for Variable Nozzles and Thrust Reverser of Aero Engines}, series = {Proceedings of ISABE 2017, ISABE-2017-21450, Manchester, September 3.-8., 2017}, journal = {Proceedings of ISABE 2017, ISABE-2017-21450, Manchester, September 3.-8., 2017}, publisher = {ISABE}, pages = {11}, language = {en} } @inproceedings{GrasseltHoeschlerSain, author = {Grasselt, David and H{\"o}schler, Klaus and Sain, Chetan Kumar}, title = {Fluid-Structure Interaction With a Fully Integrated Multiphysics Environment}, series = {Proceedings of the ASME Fluids Engineering Division Summer Meeting - 2017, presented at the ASME 2017 Fluids Engineering Division Summer Meeting, July 30-August 3, 2017, Waikoloa, Hawaii, USA, Volume 1B}, booktitle = {Proceedings of the ASME Fluids Engineering Division Summer Meeting - 2017, presented at the ASME 2017 Fluids Engineering Division Summer Meeting, July 30-August 3, 2017, Waikoloa, Hawaii, USA, Volume 1B}, publisher = {ASME}, address = {New York, NY}, isbn = {978-0-7918-5805-9}, doi = {10.1115/FEDSM2017-69078}, pages = {8}, abstract = {The paper is focusing on Fluid-Structure Interaction (FSI) process modelling to look for the aero-elastic equilibrium with commercial software packages. The center of intention is to prove whether Ansys Workbench is capable to handle industrial size FSI applications on the one side and to identify possible excitation regions in the example case on the other. The three steps taken to come to a thermal-enhanced bidirectional fluid-structure approach within a fully integrated (monolithic) multiphysics environment are explained: aerodynamic assessment, thermo-structure mechanical setup and unidirectional coupling, as well as bidirectional coupling. Each subchapter describes the specific challenges, how they are solved and which results can be obtained or expected. The paper is focusing on the setup of a bidirectional process chain and does not set the thematic priority on detailed modelling and its results.}, language = {en} } @misc{KazulaGrasseltMischkeetal., author = {Kazula, Stefan and Grasselt, David and Mischke, Marcel and H{\"o}schler, Klaus}, title = {Preliminary safety assessment of circular variable nacelle inlet concepts for aero engines in civil aviation}, series = {Safety and Reliability - Safe Societies in a Changing World}, journal = {Safety and Reliability - Safe Societies in a Changing World}, publisher = {Taylor \& Francis Group}, address = {London}, isbn = {978-0-8153-8682-7}, pages = {2459 -- 2467}, abstract = {A safe design process and its application are introduced to a concept study for circular variable aero engine inlets. The paper highlights the tasks of inlets, the compromise in designing them and how using variable inlets could solve this compromise and allow for faster and more efficient commercial aircraft. However, high safety and reliability requirements bring up disadvantages. Tackling these disadvantages, a systems engineering approach is complemented by a safety assessment process, according to Aerospace Recommended Practice ARP 4754A. Safety methods that are applicable during early phases of the product development process are presented and applied to develop feasible variable inlet concepts. Hence, safety requirements, potential failure events and resulting failure modes are systematically identified, assessed and mitigated. The mitigation of a failure condition by the means of redundancy within the adjustment control system is presented.}, language = {en} } @inproceedings{KazulaGrasseltHoeschler, author = {Kazula, Stefan and Grasselt, David and H{\"o}schler, Klaus}, title = {Common cause analysis of circular variable nacelle inlet concepts for aero engines in civil aviation}, series = {Proceedings IRF2018: 6th International Conference Integrity-Reliability-Failure, Lisbon/Portugal, 22-26 July 2018}, booktitle = {Proceedings IRF2018: 6th International Conference Integrity-Reliability-Failure, Lisbon/Portugal, 22-26 July 2018}, editor = {Silva Gomes, J. F. and Meguid, Shaker A.}, publisher = {INEGI/FEUP}, address = {Lisbon}, isbn = {978-989-20-8313-1}, pages = {759 -- 770}, abstract = {This paper presents the application of a safe design process within a concept study for variable aero engine inlets. The safety assessment method Common Cause Analysis (CCA), consisting of a Zonal Safety Analysis (ZSA), a Particular Risk Analysis (PRA) and a Common Mode Analysis (CMA), is performed on variable inlet concepts. By the means of the CCA individual failure modes and external events, which can lead to failure conditions, are identified. Potential design adaptations to mitigate these failure conditions are presented.}, language = {en} } @misc{KazulaHoeschler, author = {Kazula, Stefan and H{\"o}schler, Klaus}, title = {Ice detection and protection systems for circular variable nacelle inlet concepts}, series = {Deutscher Luft- und Raumfahrtkongress 2018, Friedrichshafen, 4. bis 6. September 2018}, journal = {Deutscher Luft- und Raumfahrtkongress 2018, Friedrichshafen, 4. bis 6. September 2018}, pages = {1 -- 15}, abstract = {This paper presents the challenge of ice protection within a concept study for variable aero engine inlets in civil aviation. An overview of variable inlet concept groups, ice detection and protection mechanisms is given. These ice protection systems are assigned to the respective inlet concept groups and evaluated regarding economic, functional and safety requirements to determine the most suitable combinations.}, language = {en} } @misc{KazulaRichHoeschleretal., author = {Kazula, Stefan and Rich, Beatrice Monique and H{\"o}schler, Klaus and Woll, Ralf}, title = {Awakening the Interest of High School Pupils in Science, Technology, Engineering and Mathematics Studies and Careers through Scientific Projects}, series = {2018 International Conference on Teaching, Assessment, and Learning for Engineering (TALE), 4-7 December 2018, Wollongong, NSW, Australia}, journal = {2018 International Conference on Teaching, Assessment, and Learning for Engineering (TALE), 4-7 December 2018, Wollongong, NSW, Australia}, publisher = {IEEE}, address = {Piscataway, NJ}, isbn = {978-1-5386-6522-0}, doi = {10.1109/TALE.2018.8615418}, pages = {259 -- 265}, abstract = {This paper presents the application of a scientific project concerning variable aero engine inlets, which was conducted within the scope of a high school course over the period of two years. The motivation of developing variable aero engine inlets with a group of pupils is introduced. The approach that is utilised during that course and its implementation are described. The results and benefits of this project for pupils, supervisor, school and university are summarised, e.g. providing the pupils with necessary knowledge and assisting them with their career choices, potentially resulting in increased enrolment numbers and lower dropout rates in science, technology, engineering and mathematics study programmes. An overview of a follow-up project that enables a larger group of pupils and a yearly implementation of a similar course is given. Within the scope of that course, university students will supervise smaller scientific projects that are conducted by groups of pupils over the period of one semester, providing additional benefits for students' soft skills, e.g. communication and conflict management skills.}, language = {en} } @misc{MhadbiMischkeHoeschleretal., author = {Mhadbi, Beya and Mischke, Marcel and H{\"o}schler, Klaus and Huppertz, Andr{\´e}}, title = {Semi-automatische Erstellung parametrisch-assoziativer 3D CAD-Modelle am Beispiel eines Flug-Kerntriebwerks}, series = {Digitalisierung und Produktentwicklung - vernetzte Entwicklungsumgebungen, 16. Gemeinsames Kolloquium Konstruktionstechnik 2018, Bayreuth, Tagungsband}, journal = {Digitalisierung und Produktentwicklung - vernetzte Entwicklungsumgebungen, 16. Gemeinsames Kolloquium Konstruktionstechnik 2018, Bayreuth, Tagungsband}, publisher = {Universit{\"a}t Bayreuth, Lehrstuhl f{\"u}r Konstruktionslehre und CAD}, address = {Bayreuth}, isbn = {978-3-00-059609-4}, pages = {236 -- 243}, abstract = {Zuk{\"u}nftige Produktentwicklungen werden auf multidisziplin{\"a}re Optimierungen eines virtuellen Modells basieren, da nur sie die Interaktionen zwischen den beteiligten Disziplinen ber{\"u}cksichtigen. Beabsichtigt man beispielsweise ein Produkt hinsichtlich seiner aerodynamischen, thermodynami-schen und statisch-dynamischen Eigenschaften zu optimieren, ist es erforderlich, die Generierung der virtuellen Produktgeometrie zu automatisieren und die interessierenden Dimensionen, welche f{\"u}r die o.g. Disziplinen relevant sind, zu parametrisieren, d.h. flexibel zu gestalten und eine potenzielle Ver{\"a}nderung der Morphologie bzw. der Abmessungen vorzusehen. Wie eine flexible, f{\"u}r die Optimierung angemessene Geometrie zu erstellen ist, ist Gegenstand des vorliegenden Artikels. Dabei wird gezeigt, wie ein 3D CAD-Modell ausgehend von einer einfachen 2D Referenzgeometrie, welche aus Grundgeometrien besteht, und von generisch, parametrisch-assoziativen Benutzerformelementen (User-Defined Features, UDFs) zu generieren ist. Der methodische Ansatz wird am Beispiel eines Kerntriebwerks konkretisiert. Der vorgestellte Prozess ist ein Schritt in Richtung einer flexiblen Geometrieerstellung, die die Durchf{\"u}hrung multidisziplin{\"a}rer Optimierung erm{\"o}glicht.}, language = {de} } @inproceedings{MischkeKazulaHoeschler, author = {Mischke, Marcel and Kazula, Stefan and H{\"o}schler, Klaus}, title = {A Comparative Concept Study and Evaluation for New Broadband Noise Absorbing Acoustic Liner Concepts for Civil Aviation}, series = {Proceedings of Global Power and Propulsion Society, Technical Conference 2019, Zurich}, booktitle = {Proceedings of Global Power and Propulsion Society, Technical Conference 2019, Zurich}, pages = {1 -- 9}, abstract = {This paper presents an approach to product rating and evaluation of different product solutions for broadband attenuation acoustic liner concepts for aerospace application. In the process, corresponding requirements have been defined for the considered system and evaluation criteria have been derived. Three "Main Evaluation Categories" (Acoustics, System Safety and Integration, Structure and Material) have been introduced to not falsify the assessment results by subject-specific exclusion criteria. A ranked space method has been selected for weighting the evaluation criteria to ensure an objective and knowledge-based rating. The rating has been carried out by a weighted point rating. Concise operational requirements and previously not considered system functions have been identified and linked to the rating and evaluation process. Building on this, further steps for the optimisation and development of the acoustic liner concepts have been presented and explained.}, language = {en} } @inproceedings{HoeschlerDenggSommerfeld, author = {H{\"o}schler, Klaus and Dengg, Hubert and Sommerfeld, Jonathan}, title = {Adaptive Preliminary-Design workflow for aero engine Secondary Air system cavities with an application case of windage and heat transfer in a roter-stator cavity with axial throughflow}, series = {ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition}, booktitle = {ASME Turbo Expo 2018: Turbomachinery Technical Conference and Exposition}, publisher = {The American Society of Mechanical Engineers}, address = {New York, N.Y.}, isbn = {978-0-7918-5110-4}, doi = {10.1115/GT2018-76201}, pages = {12}, abstract = {At the preliminary design stage of theengine design process,the behaviourand efficiency of different engine designs are investigated and evaluated in order to find a best matching design for a set ofengine objectives and requirements.The prediction of critical part temperaturesas well as the reduction of the uncertainty of these predictions is decisive to bid a competitive technology in aerospace technology. Automated workflows and Design of Experiments (DOE) are widely used to investigate large number of designs and to find an optimized solution.Nowadays, technological progress in computational power as well as new strategies for data handling and management enables the implementation of large DOEs and multi-objective optimizations in less time, whichalso allows the consideration of more detailed investigations in early design stages. This paper describes an approach for apreliminary-design workflow that implementsadaptivemodelling and evaluation methodsfor cavities in the secondary air system (SAS). The starting point for the workflow is a parametric geometry model defining the rotating and static components. The flow network withintheSAS isautomatically recognizedand CFD and Thermal-FE modelsare automatically generatedusing a library of generic models. Adaptiveevaluation algorithms are developed and used to predict values for structural, air system and thermal behaviour. Furthermore, these models and evaluation techniques can be implemented in a DOE to investigate the impact of design parameters onthe predicted values. The findings from the automated studies can beused to enhance the boundary conditions of actual design models in later design stages. A designinvestigation on a rotor-stator cavity with axial through flow has been undertaken usingthe proposedworkflow to extract windage, flow field and heat transfer informationfrom adiabatic CFD calculations for use in thermal modelling. A DOE has been set up to conduct a sensitivity analysis of the flow field properties and to identify the impact of the design parameters. Additionally,impacts on the distribution of the flow field parametersalong the rotating surface are recognized, which offers a better prediction for local effects in the thermal FE model.}, language = {en} } @misc{KazulaHoeschler, author = {Kazula, Stefan and H{\"o}schler, Klaus}, title = {A systems engineering approach to variable intakes for civil aviation}, series = {Proceedings of the Institution of Mechanical Engineers. Part G, Journal of Aerospace Engineering}, volume = {234(2020)}, journal = {Proceedings of the Institution of Mechanical Engineers. Part G, Journal of Aerospace Engineering}, number = {10}, issn = {2041-3025}, doi = {10.1177/0954410019836903}, pages = {1721 -- 1729}, abstract = {A systems engineering approach to develop variable nacelle intakes for aero engines in civil aviation is presented. The goal of this methodical approach is to find solutions to design problems that can be successfully utilised in aviation without further effort during the certification. By using variable intakes, aircraft and aero engine manufacturers can fulfil their customers' needs for safe, efficient and fast travelling. Therefore, a system shall be installed which is able to modify the nacelle intake contour between two extrema. On the one hand, a sharp thin contour, which produces low drag and allows to fly faster or more efficiently, is optimal during cruise condition. On the other hand, a round thick intake lip is necessary to avoid flow separations with the potential to cause dangerous events during take-off and climb conditions. The utilised systems engineering approach is introduced. The executed steps and methods used for creating and evaluating concept variants for variable intakes are displayed particularly. Those contain the determination and evaluation of requirements and functions as well as the generation and assessment of concepts. Finally, yet importantly, following tasks are presented.}, language = {en} } @misc{KazulaHoeschler, author = {Kazula, Stefan and H{\"o}schler, Klaus}, title = {Ice detection and protection systems for circular variable nacelle inlet concepts}, series = {CEAS Aeronautical Journal}, volume = {11}, journal = {CEAS Aeronautical Journal}, number = {1}, issn = {1869-5590}, doi = {10.1007/s13272-019-00413-1}, pages = {229 -- 248}, abstract = {This paper presents the challenge of ice protection within a concept study for variable pitot inlets of aero engines in transonic and supersonic civil aviation. An overview of variable inlet concept groups that adjust the inlet geometry by rigid segment repositioning, elastic surface deformation, or boundary layer control is given. Ice detection mechanisms and various pneumatic, fluid, as well as electric ice protection systems are presented. These ice protection systems are assigned to the respective inlet concept groups and evaluated regarding economic, functional, and safety requirements by means of pairwise comparison and weighted point rating to determine the most suitable combinations.}, language = {en} } @misc{KazulaWoellnerGrasseltetal., author = {Kazula, Stefan and W{\"o}llner, Mark and Grasselt, David and H{\"o}schler, Klaus}, title = {Parametric Design Study on Aerodynamic Characteristics of Variable Pitot Inlets for Transonic and Supersonic Civil Aviation}, series = {MATEC Web of Conferences : Proceedings of the 9th EASN International Conference on Innovation in Aviation \& Space}, volume = {304}, journal = {MATEC Web of Conferences : Proceedings of the 9th EASN International Conference on Innovation in Aviation \& Space}, issn = {2261-236X}, doi = {10.1051/matecconf/201930402017}, pages = {8}, abstract = {This paper reveals the influence of selected geometric parameters on the aerodynamic performance of circular variable aero engine inlets in transonic and supersonic civil aviation. The trade-off in inlet design and aerodynamic evaluation parameters are presented. The approach to investigate the dependencies between the aerodynamic and geometric parameters at different flight conditions by means of a parametric design study is introduced. The dependencies of inlet drag and efficiency from geometric parameters at flight speeds of Mach 0.95 up to Mach 1.6 are identified. Although entailing additional weight, the inlet length represents the parameter with the highest potential for drag reduction by up to 50\% in the selected design space. Ideal geometries for variable pitot inlets are determined. After considering weight, their potential range benefit nearly disappears for subsonic applications, but remains above 20\% for supersonic flight at Mach 1.6.}, language = {en} } @misc{KazulaMischkeKoenigetal., author = {Kazula, Stefan and Mischke, Marcel and K{\"o}nig, Paul and H{\"o}schler, Klaus}, title = {Evaluation of Variable Pitot Inlet Concepts for Transonic and Supersonic Civil Aviation}, series = {MATEC Web of Conferences : Proceedings of the 9th EASN International Conference on Innovation in Aviation \& Space}, volume = {304}, journal = {MATEC Web of Conferences : Proceedings of the 9th EASN International Conference on Innovation in Aviation \& Space}, issn = {2261-236X}, doi = {10.1051/matecconf/201930402016}, pages = {8}, abstract = {This paper describes the selection of the ideal variable inlet concept group by utilising results of aerodynamic investigations, system safety analyses and integration studies. Aerodynamic and functional inlet requirements are explained and variable inlet concept groups are introduced. The concept evaluation by means of a weighted point rating is presented. The respective concept groups are analysed and evaluated regarding economic, functional and safety requirements. By means of this evaluation, the concept group that adjusts the inlet geometry by rigid segment repositioning is identified as most suitable concept group. The early selection of the most suitable concept group enables more detailed subsequent concept investigations, potentially enabling the technology of variable inlets for future commercial aircraft.}, language = {en} } @misc{KazulaWoellnerGrasseltetal., author = {Kazula, Stefan and W{\"o}llner, Mark and Grasselt, David and H{\"o}schler, Klaus}, title = {Parametric design and aerodynamic analysis of circular variable aero engine inlets for transonic and supersonic civil aviation}, series = {Proceedings of the 24th ISABE Conference : ISABE 2019-24018}, journal = {Proceedings of the 24th ISABE Conference : ISABE 2019-24018}, address = {Canberra}, pages = {39}, abstract = {This paper focusses on the challenge of determining the ideal inlet geometries within a concept study for variable pitot aero engine inlets in transonic and supersonic civil aviation. The trade-off in inlet design and the geometric parameters of inlets for different Mach numbers are introduced. The utilised process of the parametric design study and its implementation are presented. The dependencies of inlet drag and occurrence of flow separation from geometric parameters are examined. The ideal inlet geometries are identified to determine the potential aerodynamic benefit of using variable pitot inlets. The comparison of the identified geometries with the reference reveals a significant drag reduction at the investigated flight speeds of Mach 0.95, 1.3 and 1.6. While the drag reduction potentially leads to decreased fuel consumption and increased flight range, the application of variable inlet systems entails additional weight and complexity. By means of a simplified Breguet range equation, the benefit of using variable pitot inlets has been determined. For an additional weight of 500 kg per variable inlet, the range benefit nearly disappears for subsonic applications up to Mach 0.95, while a range benefit of over 20\% remains for supersonic applications at Mach 1.6.}, language = {en} } @misc{KoenigMischkePohletal., author = {K{\"o}nig, Paul and Mischke, Marcel and Pohl, Michael and Kazula, Stefan and H{\"o}schler, Klaus}, title = {Concept Development and Evaluation for a Broadband Noise Absorbing Acoustic Liner Concept for Aviation}, series = {24th International Society For Air Breathing Engines (ISABE-2019-24261), 22.-27. September 2019}, journal = {24th International Society For Air Breathing Engines (ISABE-2019-24261), 22.-27. September 2019}, abstract = {This paper presents design adaptations during the further development of innovative broadband acoustic liner concepts (Foil Helmholtz Resonator Liner; FHR-Liners) which utilise flexible foils within a honeycomb structure to attenuate engine and aircraft noise. The requirements for acoustic liners in aviation are described and utilised to derive evaluation criteria. Modifications of the FHR-Liner concept are introduced. A suitable concept evaluation method based on VDI 2225 is applied to evaluate the modified liner concepts concerning the main evaluation criteria.}, language = {en} }