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  • 1
    Online Resource
    Online Resource
    Preliminary safety Assessment on System Design Level for Broadband Acoustic Liner Concepts for Aviation
    EDP Sciences ; 2019
    In:  MATEC Web of Conferences Vol. 304 ( 2019), p. 04010-
    Details
    In: MATEC Web of Conferences, EDP Sciences, Vol. 304 ( 2019), p. 04010-
    Abstract: Selected methods of the aviation safety assessment process according to ARP 4761 are introduced and conducted within the scope of a concept study for future broadband acoustic liners. While having similar primary functions and basic design, the acoustic liner concepts diverge concerning subfunctions and potential malfunctions. With the ARP 4761 safety assessment methods, significant differences in sub functions and possible malfunctions of the concepts can be identified. The results of the safety assessment are discussed, and the concepts are evaluated in terms of feasibility and safety.
    Type of Medium: Online Resource
    ISSN: 2261-236X
    URL: Article
    DOI: 10.1051/matecconf/201930404010
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2019
    detail.hit.zdb_id: 2673602-0
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  • 2
    Online Resource
    Online Resource
    Parametric Design Study on Aerodynamic Characteristics of Variable Pitot Inlets for Transonic and Supersonic Civil Aviation
    EDP Sciences ; 2019
    In:  MATEC Web of Conferences Vol. 304 ( 2019), p. 02017-
    Details
    In: MATEC Web of Conferences, EDP Sciences, Vol. 304 ( 2019), p. 02017-
    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.
    Type of Medium: Online Resource
    ISSN: 2261-236X
    URL: Article
    DOI: 10.1051/matecconf/201930402017
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2019
    detail.hit.zdb_id: 2673602-0
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  • 3
    Online Resource
    Online Resource
    Comparison of convective heat transfer in metal foam-filled channels of three different cross-sections
    Informa UK Limited ; 2023
    In:  Numerical Heat Transfer, Part A: Applications
    Details
    In: Numerical Heat Transfer, Part A: Applications, Informa UK Limited
    Type of Medium: Online Resource
    ISSN: 1040-7782 , 1521-0634
    URL: Article
    DOI: 10.1080/10407782.2023.2181892
    Language: English
    Publisher: Informa UK Limited
    Publication Date: 2023
    detail.hit.zdb_id: 2015653-4
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  • 4
    Online Resource
    Online Resource
    DMA of TPU Films and the Modelling of Their Viscoelastic Properties for Noise Reduction in Jet Engines
    MDPI AG ; 2022
    In:  Polymers Vol. 14, No. 23 ( 2022-12-03), p. 5285-
    Details
    In: Polymers, MDPI AG, Vol. 14, No. 23 ( 2022-12-03), p. 5285-
    Abstract: Due to current developments in jet engine design, the acoustic performance of conventional acoustic liners needs to be improved with respect to lower frequency spectrums and broadband absorption. In this context, the present study aimed to determine the viscoelastic material properties of a thermoplastic polyurethane (TPU) film for targeted application in novel acoustic liners with integrated film material for enhanced noise reduction. Therefore, a dynamic mechanical analysis (DMA) was performed to determine these viscoelastic material properties. Based on the acquired data, the time-temperature shift (TTS) was applied to obtain the material’s temperature- and frequency-dependent mechanical properties. In this regard, the William-Landel-Ferry (WLF) method and an alternative polynomial approach determining the shift factors were investigated and compared. Furthermore, a generalized Maxwell model—so-called Prony-series—with and without pre-smoothing utilizing of a fractional rheological model was applied to approximate the measured storage and loss modulus and to provide a material model that can be used in finite element analyses. Finally, the results were discussed concerning the application of the films in acoustic liners under the conditions of a standard flight cycle and the applied loads. The present investigations thus provide a method for characterizing polymer materials, approximating their mechanical behavior for vibration applications at different ambient temperatures and enabling the identification of their operational limits during the application in acoustic liners.
    Type of Medium: Online Resource
    ISSN: 2073-4360
    URL: Article
    DOI: 10.3390/polym14235285
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2527146-5
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  • 5
    Online Resource
    Online Resource
    Aerodynamic assessment of nozzle area variation by core fairing modulation
    Springer Science and Business Media LLC ; 2017
    In:  CEAS Aeronautical Journal Vol. 8, No. 3 ( 2017-9), p. 493-504
    Details
    In: CEAS Aeronautical Journal, Springer Science and Business Media LLC, Vol. 8, No. 3 ( 2017-9), p. 493-504
    Type of Medium: Online Resource
    ISSN: 1869-5582 , 1869-5590
    URL: Article
    DOI: 10.1007/s13272-017-0253-4
    Language: English
    Publisher: Springer Science and Business Media LLC
    Publication Date: 2017
    detail.hit.zdb_id: 2610302-3
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  • 6
    Online Resource
    Online Resource
    Evaluation of Variable Pitot Inlet Concepts for Transonic and Supersonic Civil Aviation
    EDP Sciences ; 2019
    In:  MATEC Web of Conferences Vol. 304 ( 2019), p. 02016-
    Details
    In: MATEC Web of Conferences, EDP Sciences, Vol. 304 ( 2019), p. 02016-
    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.
    Type of Medium: Online Resource
    ISSN: 2261-236X
    URL: Article
    DOI: 10.1051/matecconf/201930402016
    Language: English
    Publisher: EDP Sciences
    Publication Date: 2019
    detail.hit.zdb_id: 2673602-0
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  • 7
    Online Resource
    Online Resource
    Experimental and Numerical Investigation of Novel Acoustic Liners and Their Design for Aero-Engine Applications
    MDPI AG ; 2022
    In:  Aerospace Vol. 10, No. 1 ( 2022-12-21), p. 5-
    Details
    In: Aerospace, MDPI AG, Vol. 10, No. 1 ( 2022-12-21), p. 5-
    Abstract: This paper presents a combined experimental and numerical investigation on a novel liner concept for enhanced low-frequency and broadband acoustic attenuation. In particular, two different realizations, derived from conventional Helmholtz resonators (HR) and plate resonators (PR) are investigated, which both deploy flexible materials with material inherent damping. In this context, a comprehensive experimental investigation was carried out focusing the identification and evaluation of various geometric parameters and material properties on the acoustics dissipation and related properties of various materials in a simplified setup of a single Helmholtz resonator with flexible walls (FHR concept). Furthermore, a parameter study based on analytical models was performed for both liner concepts, taking into account material as well as geometric parameters and their effects on transmission loss. In addition, design concepts that enable cylindrical or otherwise curved liner structures and the corresponding manufacturing technologies are presented, while considering essential structural features such as drainage. With respect to the potential application in jet engines, a structural–mechanical analysis considering the relevant load cases to compare and discuss the mechanical performance of a classical HR and the FHR concept liner is presented. Finally, both concepts are evaluated and possible challenges and potentials for further implementation are described.
    Type of Medium: Online Resource
    ISSN: 2226-4310
    URL: Article
    DOI: 10.3390/aerospace10010005
    Language: English
    Publisher: MDPI AG
    Publication Date: 2022
    detail.hit.zdb_id: 2756091-0
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  • 8
    Online Resource
    Online Resource
    On the Potentials of the Integration of Pressure Gain Combustion with a Hybrid Electric Propulsion System
    MDPI AG ; 2023
    In:  Aerospace Vol. 10, No. 8 ( 2023-08-15), p. 710-
    Details
    In: Aerospace, MDPI AG, Vol. 10, No. 8 ( 2023-08-15), p. 710-
    Abstract: As the issue of pollutant emissions from aviation propulsion escalates, research into alternative powertrains is gaining momentum. Two promising technologies are the Hybrid Electric Propulsion System (HEPS) and Pressure Gain Combustion (PGC). HEPS is expected to reduce pollutant emissions by decreasing fuel consumption, whereas PGC uses detonation in the combustor to increase the thermal efficiency of engines by elevating the total pressure during combustion. This study extensively explores the integration of these two emerging technologies, thoroughly assessing the advantages that arise from their combination. First, the renowned turboprop engine PW127 is benchmarked and modeled using Gasturb software. The model is integrated into Simulink using the T-MATS tool, with HEPS and pressure gain components added to analyze the thermodynamics of various configurations under different pressure gain values and HEPS parameters. The analysis, conducted up to the cruise phase of the baseline aircraft, reveals that applying pressure gain combustion through Rotating Detonation Combustion (RDC) results in a more significant increase in efficiency and decrease in fuel consumption compared to HEPS with conventional gas turbines. However, HEPS helps maintain a more uniform combustor inlet condition and reduces the Turbine Inlet Temperature (TIT) at the takeoff phase, where the highest TIT otherwise occurs. The results suggest that integrating HEPS with PGC can be beneficial in maintaining optimal combustor conditions and mitigating turbine efficiency degradation.
    Type of Medium: Online Resource
    ISSN: 2226-4310
    URL: Article
    DOI: 10.3390/aerospace10080710
    Language: English
    Publisher: MDPI AG
    Publication Date: 2023
    detail.hit.zdb_id: 2756091-0
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  • 9
    Online Resource
    Online Resource
    Evaluation of variable pitot inlet concepts for transonic and supersonic civil aviation
    Emerald ; 2020
    In:  Aircraft Engineering and Aerospace Technology Vol. 92, No. 6 ( 2020-02-28), p. 807-815
    Details
    In: Aircraft Engineering and Aerospace Technology, Emerald, Vol. 92, No. 6 ( 2020-02-28), p. 807-815
    Abstract: This paper aims to describe the selection of the ideal variable inlet concept group by using results of aerodynamic investigations, system safety analyses and integration studies. Design/methodology/approach 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. Findings By means of this evaluation, the concept group that adjusts the inlet geometry by rigid segment repositioning is identified as most suitable concept group. Originality/value 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.
    Type of Medium: Online Resource
    ISSN: 1748-8842 , 1748-8842
    URL: Article
    DOI: 10.1108/AEAT-11-2019-0225
    Language: English
    Publisher: Emerald
    Publication Date: 2020
    detail.hit.zdb_id: 2014643-7
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    Online Resource
  • 10
    Online Resource
    Online Resource
    Identification of efficient geometries for variable pitot inlets for supersonic transport
    Emerald ; 2020
    In:  Aircraft Engineering and Aerospace Technology Vol. 92, No. 7 ( 2020-06-16), p. 981-992
    Details
    In: Aircraft Engineering and Aerospace Technology, Emerald, Vol. 92, No. 7 ( 2020-06-16), p. 981-992
    Abstract: This paper aims to reveal the influence of selected geometric parameters on the aerodynamic performance of circular variable aero engine inlets in transonic and supersonic civil aviation. Design/methodology/approach The trade-off in inlet design and aerodynamic evaluation parameters is 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. Findings 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. Originality/value Hence, the technology of circular variable pitot inlets for supersonic transport aircraft could be a way to achieve the ambitious ecological, safety and economic goals for future civil aviation.
    Type of Medium: Online Resource
    ISSN: 1748-8842 , 1748-8842
    URL: Article
    DOI: 10.1108/AEAT-11-2019-0228
    Language: English
    Publisher: Emerald
    Publication Date: 2020
    detail.hit.zdb_id: 2014643-7
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