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Gust response of an elasto-flexible morphing wing using fluid–structure interaction simulations

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Chinese Journal of Aeronautics 2024年第2期37卷 45-57页

作者： jonathan PFLÜGER Christian BREITSAMTER Department of Mechanical Engineering Technical University of MunichGarching 85748Germany

Small and micro unmanned aircraft are the focus of scientific interest due to their wide range of *** often operate in a highly unstable flight environment where the application of new morphing wing technologies offers the opportunity to improve flight *** investigated concept comprises port and starboard adjustable wings,and an adaptive elastoflexible membrane serves as the lifting *** focus is on the benefits of the deforming membrane during the impact of a one-minus-cosine type *** a low Reynolds number of Re=264000,the morphing wing model is investigated numerically by unsteady fluid-structure interaction ***,the numerical results are validated by experimental data from force and moment,flow field,and deformation ***,with the rigid wing as the baseline,the flexible case is investigated,focusing on the advantages of the elastic *** all configurations studied,the maximum amplitude of the lift coefficient under gust load shows good agreement between the experimental and numerical *** the decay of the gust,they differ more the higher the aspect ratio of the *** considering the flow field,the main differences are due to the separation behavior on the upper side of the *** flow reattaches earlier in the experiments than in the simulations,which explains the higher lift values observed in the *** at one intermediate configuration does the lift amplitude of the rigid configuration exceeds that of the flexible by about 12%,with the elastic membrane resulting in a smaller and more uniform peak load,which is also evident in the wing loading and hence in the root bending moment.

关键词： Membrane wing Morphing wing Flexible wing surface Computational fluid dynam-ics Fluid-structure interaction Unsteady inflow condition Gust response

维普期刊数据库

Biomedical engineering and erectile restoration:design considerations for urologic prosthetics

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Asian Journal of Andrology 2020年第1期22卷 15-19页

作者： jonathan J Lund Prosthetic Urology Research and Development Boston ScientificMinnetonkaMN 55343USA

For patients with moderate-to-severe erectile dysfunction,implantable penile prostheses continue to be a viable *** device developers apply design controls during the development cycle to ensure that a product performs as intended in the final use *** process relies heavily on the principles of systems engineering and documents every facet of performance,unmet need,and *** better understand design philosophy,it is important to frame benchmarked performance outcomes in the context of the ideal *** consideration of erectile anatomy and physiology,including flaccid state,transitional phases,and full tumescence,informs penile prosthesis design philosophy and provides the foundation for product advancement.

关键词： design controls engineering fluid dynamics inflatable penile prosthesis systems engineering

Formation of efficient dye-sensitized solar cells by introducing an interfacial layer of hierarchically ordered macro-mesoporous Tio_2 film

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Science China Chemistry 2011年第6期54卷 930-935页

作者： HALPERT jonathan E State Key Laboratory of Multi-phase Complex Systems Institute of Process Engineering Chinese Academy of Sciences

Hierarchically ordered macro-mesoporous Tio2 films (Ti-Ma-Me) were fabricated on fluorine-doped tin oxide (FTo) substrates through the confinement self-assembly method. The prepared Ti-Ma-Me possesses periodically ordered structure and a large specific surface area, which was applied as an interfacial layer between the nanocrystalline Tio2 film (P25-Tio2) and FTo electrode in the dye-sensitized solar cell (DSSC). The introduction of a Ti-Ma-Me interfacial layer increased the shortcircuit current density (Jsc) from 7.49 to 10.65 mA/cm2 and the open-circuit voltage (Voc) from 0.65 to 0.70 V as the result of its improved light harvesting efficiency by allowing for the high roughness factor and enhanced multiple internal reflection or scattering as well as reducing the back-transport reaction by blocking direct contact between the electrolyte and FTo electrode. Therefore, the photovoltaic conversion efficiency (η) was improved by 83% from 3.04% to 5.55%, as compared to a device using a bare P25 Tio2 photoanode.

关键词： dye-sensitized solar cells hierarchical ordered macro-mesoporous photoanode

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ACCELERATED oPTIMIZATIoN WITH oRTHoGoNALITY CoNSTRAINTS

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Journal of Computational Mathematics 2021年第2期39卷 207-226页

作者： jonathan W.Siegel Department of Mathematics Pennsylvania State UniversityUniversity ParkPAUSA

We develop a generalization of Nesterov’s accelerated gradient descent method which is designed to deal with orthogonality *** demonstrate the effectiveness of our method,we perform numerical experiments which demonstrate that the number of iterations scales with the square root of the condition number,and also compare with existing state-of-the-art quasi-Newton methods on the Stiefel *** experiments show that our method outperforms existing state-of-the-art quasi-Newton methods on some large,ill-conditioned problems.

关键词： Riemannian optimization Stiefel manifold Accelerated gradient descent Eigenvector problems Electronic structure calculations

Quantum machine learning

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National Science Review 2019年第1期6卷 26-28页

作者： jonathan Allcock Shengyu Zhang Tencent Quantum Laboratory

INTRoDUCTIoN Quantum machine learning is at the crossroads of two of the most exciting current areas of research:quantum computing and classical machine learning. Although the field is still in its infancy,the body of literature is already large enough to warrant several review articles [1–3]. This short survey focuses on a selection of significant recent results on the subtopic of quantum neural net-

关键词： RBM Quantum machine learning

Chemical vapor deposition growth of monolayer MoSe2 nanosheets

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Nano Research 2014年第4期7卷 511-517页

作者： jonathan C. Shaw Hailong Zhou Yu Chen Nathan o. Weiss Yuan Liu Yu Huang Xiangfeng Duan Department of Chemistry and Biochemistry University of California Los Angeles CA 90095 USA Department of Materials Science and Engineering University of California Los Angeles CA 90095 USA California NanoSystems Institute University of California Los Angeles CA 90095 USA

The synthesis of two-dimensional （2D） layered materials with controllable thickness is of considerable interest for diverse applications. Here we report the first chemical vapor deposition growth of single- and few-layer MoSe2 nanosheets. By using Se and Moo3 as the chemical vapor supply, we demonstrate that highly crystalline MoSe2 can be directly grown on the 300 nm Sio2/Si substrates to form optically distinguishable single- and multi-layer nanosheets, typically in triangular shaped domains with edge lengths around 30 btm, which can merge into continuous thin films upon further growth. Micro-Raman spectroscopy and imaging was used to probe the thickness-dependent vibrational properties. Photoluminescence spectroscopy demonstrates that MoSe2 monolayers exhibit strong near band edge emission at 1.55 eV, while bilayers or multi-layers exhibit much weaker emission, indicating of the transition to a direct band gap semiconductor as the thickness is reduced to a monolayer.

关键词： chemical vapor deposition molybdenum diselenide two-dimensional materials transition metaldichalcogenide layered materials semiconductor

Polychromatic metasurfaces for complete control of phase and polarization in the mid-infrared

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Light(Science & Applications) 2023年第11期12卷 2266-2268页

作者： You Zhou jonathan A.Fan Department of Electrical Engineering Stanford UniversityStanfordCA 94305USA

Multifunctional metasurfaces based on wavelength-decoupled supercells are experimentally demonstrated,enabling new regimes of optical control for arbitrary orthogonal polarizations at different wavelengths.

关键词： polarization surfaces phase

URBAN STREAM RESToRATIoN AND APPLIED PRACTICES IN NoRTHEAST ILLINoIS

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Journal of Green Building 2017年第2期12卷 13-27页

作者： jonathan Koepke Encap Incorporated 2585 Wagner CourtDekalbIL 60115

INTRoDUCTIoN:In-stream and watershed dynamics in urban and urbanizing areas have significant impacts on local property and infrastructure,as well as the quality of the stream itself including:water quality,habitat,physical characteristics,and *** land development occurs,natural vegetation and exposed soils are converted to buildings,pavement and other impervious *** leads to increased runoff during storm events as well as decreasing the time that it takes that stormwater to reach streams,wetlands,and other stormwater storage and conveyance *** hydrologic changes in a watershed often occur at a rapid pace which results in rapid destabilization and degradation of streams and *** and streams are naturally dynamic *** naturally erode and reshape themselves based on changes to the watershed or the stream *** and deposition are natural processes that have always been important components of stream systems and in and of themselves are not *** natural stream dynamics are rapidly accelerated,however,an entire series of negative impacts to the stream and the biological systems that are depended on the stream *** destabilization of streams often leads to significant bank and bed erosion that negatively impact stream health and frequently leads to negative impact to property,buildings and structures,as well as public *** approaches to stream bank and bed stabilization often involved channelization,armoring,and other gray infrastructure techniques to protect public and private property in the effected reaches of streams and rivers without taking into account the overall stream system *** stabilization efforts frequently led to other unintended consequences by accelerating the rate of bank and bed erosion in untreated reaches,inadvertent flooding,and other infrastructure *** complex nature of stream dynamics and fluvial geomorphology when applied to urban stream s

关键词： Stream Restoration Watershed Development Bioengineering Streambank Stabilization Riparian Restoration

Combined effects of fretting and pollutant particles on the contact resistance of the electrical connectors

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Progress in Natural Science:Materials International 2017年第3期27卷 385-390页

作者： Zhigang Kong jonathan Swingler Research Laboratory of Electrical Contacts Beijing University of Post and Telecommunications School of Engineering & Physical Sciences Heriot-Watt University

Usually,when electrical connectors operate in vibration environments,fretting will be produced at the contact *** addition,serious environmental pollution particles will affect contact resistance of the *** fretting will worsen the reliability of connectors with the pollutant *** combined effects of fretting and quartz particles on the contact resistance of the gold plating connectors are studied with a fretting test *** results show that the frequencies have obvious effect on the contact *** higher the frequency,the higher the contact resistance *** quartz particles cause serious wear of gold plating,which make the nickel and copper layer exposed quickly to increase the contact *** in high humidity environments,water supply certain adhesion function and make quartz particles easy to insert or cover the contact surfaces,and even cause opening resistance.

关键词： Gold plating Fretting Contact failure Electrical contact