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A new non-linear vortex lattice method:Applications to wing aerodynamic optimizations

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Chinese Journal of Aeronautics 2016年第5期29卷 1178-1195页

作者： Oliviu Sugar gabor andreea Koreanschi Ruxandra Mihaela Botez LARCASE Laboratory of Applied Research in Active Controls Avionics and Aeroservoelasticity cole de Technologie Supérieure

This paper presents a new non-linear formulation of the classical Vortex Lattice Method （VLM） approach for calculating the aerodynamic properties of lifting surfaces. The method accounts for the effects of viscosity, and due to its low computational cost, it represents a very good tool to perform rapid and accurate wing design and optimization procedures. The mathematical model is constructed by using two-dimensional viscous analyses of the wing span-wise sections, according to strip theory, and then coupling the strip viscous forces with the forces generated by the vortex rings distributed on the wing camber surface, calculated with a fully three-dimensional vortex lifting law. The numerical results obtained with the proposed method are validated with experimental data and show good agreement in predicting both the lift and pitching moment, as well as in predicting the wing drag. The method is applied to modifying the wing of an Unmanned Aerial System to increase its aerodynamic efficiency and to calculate the drag reductions obtained by an upper surface morphing technique for an adaptable regional aircraft wing.

关键词： Aerodynamic design Aerodynamic optimization Enhanced potential method Morphing wing Nonlinear vortex latticemethod Quasi-3D aerodynamic method UAS optimization

Optimization and design of an aircraft's morphing wing-tip demonstrator for drag reduction at low speed, Part Ⅰ–Aerodynamic optimization using genetic, bee colony and gradient descent algorithms

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Chinese Journal of Aeronautics 2017年第1期30卷 149-163页

作者： andreea Koreanschi Oliviu Sugar gabor Joran Acotto Guillaume Brianchon Gregoire Portier Ruxandra Mihaela Botez Mahmoud Mamou Youssef Mebarki LARCASE Laboratory of Applied Research in Active Control Avionics and Aeroservoelasticity Ecole de Technologie Superieure Montreal H3C1K3 Canada Aerodynamics Laboratory NRC Aerospace National Research Council Canada Ottawa K1A0R6 Canada

In this paper, an ‘in-house＇ genetic algorithm is described and applied to an optimization problem for improving the aerodynamic performances of an aircraft wing tip through upper surface morphing. The algorithm＇s performances were studied from the convergence point of view, in accordance with design conditions. The algorithm was compared to two other optimization methods,namely the artificial bee colony and a gradient method, for two optimization objectives, and the results of the optimizations with each of the three methods were plotted on response surfaces obtained with the Monte Carlo method, to show that they were situated in the global optimum region. The optimization results for 16 wind tunnel test cases and 2 objective functions were presented. The 16 cases used for the optimizations were included in the experimental test plan for the morphing wing-tip demonstrator, and the results obtained using the displacements given by the optimizations were evaluated.

关键词： Artificial bee colony Airfoil optimization Genetic algorithm Morphing wing Optimization

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Dual mean Minkowski measures of symmetry for convex bodies

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Science China Mathematics 2016年第7期59卷 1383-1394页

作者： GUO Qi TOTH gabor Department of Mathematics Suzhou University of Science and Technology Department of Mathematics Rutgers University

We introduce and study a sequence of geometric invariants for convex bodies in finite-dimensional spaces, which is in a sense dual to the sequence of mean Minkowski measures of symmetry proposed by the second author. It turns out that the sequence introduced in this paper shares many nice properties with the sequence of mean Minkowski measures, such as the sub-arithmeticity and the upper-additivity. More meaningfully, it is shown that this new sequence of geometric invariants, in contrast to the sequence of mean Minkowski measures which provides information on the shapes of lower dimensional sections of a convex body, provides information on the shapes of orthogonal projections of a convex body. The relations of these new invariants to the well-known Minkowski measure of asymmetry and their further applications are discussed as well.

关键词： geometric invariant measure of symmetry dual measure of symmetry simplex affine diameter

Two-dimensional decaying turbulence in confined geometries

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International Journal of Modeling, Simulation, and Scientific Computing 2014年第S01期5卷 111-119页

作者： gabor Toth gabor Hazi Hungarian Academy of Sciences Eotvos University Faculty of Science Department of Physics of Complex System H-1117 BudapestPazmany Peter Setany 1/AHungary Centre for Energy Research Budapest H-1525 Konkoly Th.29-33Hungary

Several interesting phenomena have been observed simulating two-dimensional decaying turbulence in bounded *** this paper,an overview is given about our observations obtained by simulating freely decaying turbulence in different regular polygon shaped containers with no-slip *** these simulations the lattice Boltzmann method has been used as a numerical *** initial Reynolds number based on the container dimension was in the order of 10,*** initial condition was the same in each simulation,therefore,we were able to compare the effect of geometrical constraints on the evolution of relevant physical quantities such as the kinetic energy and the enstrophy.

关键词： Lattice Boltzmann method two-dimensional turbulence no-slip walls

Global optimum of microstructure parameters in the CMWP line-profile-analysis method by combining Marquardt-Levenberg and Monte-Carlo procedures

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Journal of Materials Science & Technology 2019年第7期35卷 1508-1514页

作者： gabor Ribarik Bertalan Joni Tamas Ungar Department of Materials Physics Edtvos University BudapestPO Box 32H-15J8Hungary School of Materials The University of ManchesterM139PLUK

Line profile analysis of X-ray and neutron diffraction patterns is a powerful tool for determining the microstructure of crystalline materials. The Convolutional-Multiple-Whole-Profile (CMWP) procedure is based on physical profile functions for dislocations, domain size, stacking faults and twin boundaries. Order dependence, strain anisotropy, hkl dependent broadening of planar defects and peak shape are used to separate the effect of different lattice defect types. The Marquardt-Levenberg (ML) numerical optimiza-tion procedure has been used successfully to determine crystal defect types and densities. However, in more complex cases like hexagonal materials or multiple phases the ML procedure alone reveals uncer-tainties. In a new approach the ML and a Monte-Carlo statistical method are combined in an alternative manner. The new CMWP procedure eliminates uncertainties and provides globally optimized parameters.

关键词： X-ray line profile analysis Neutron line profile analysis CMWP Global optimum Dislocation densities Grain size Planar defects Monte-Carlo method

Changes in the phenology of the ground beetle Pterostichus madidus

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Insect Science 2011年第4期18卷 462-472页

作者： gabor Pozsgai Nick A. Littlewood Macaulay Land Use Research IneUtute Craigiebuckler Aberdeen UK

A growing body of evidence shows that climate change can alter the phenology of plants and animals. In this study long-term data from the UK Environmental Change Network （ECN） were analyzed to investigate whether there has been a change in the phenology of the ground beetle Pterostichus madidus （Fabricius, 1775）. Pitfall trap data were available from 12 ECN sites across the United Kingdom, most of which have been in operation for more than 15 years. Weather and vegetation datasets were also utilized. Pitfall trap lines were categorized to eight vegetation types. Trend analysis over time was carried out first using all the available dates of capture events, then the datasets grouped by vegetation type and site. Shifts in high-activity periods were also analyzed. P madidus appearance dates advanced significantly at seven sites and in five vegetation types. Peak activity advanced at two sites. At one site the timing of activity became significantly later. The last day of activity did not change significantly, supporting the theory that the cessation of the activity period is more likely to be controlled by photoperiod than temperature. The relationships between phenological variables and climatic factors were also investigated. Howe＇ver, no significant correlations were detected. These results demonstrate that between 1992 and 2008, phenology ofP madidus at seven sites from the eight analyzed has changed. Global warming may be driving these changes and future work will investigate underlying processes.

关键词： black clock beetle climate change Environmental Change Network life-history long-term data trend analysis

A review of the sentinel prey method as a way of quantifying invertebrate predation under field conditions

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Insect Science 2017年第4期24卷 528-542页

作者： gabor L. Lovei Marco Ferrante Department of Agroecology Flakkebjerg Research Centre Aarhus University Forsgsvej 1 DK-4200 Slagelse Denmark

Sentinel prey can provide a direct, quantitative measure of predation under field conditions. Live sentinel prey provides more realistic data but rarely allows the partitioning of the total predation pressure; artificial prey is less natural but traces left by different predators are identifiable, making it suitable for comparative studies. We reviewed the available evidence of the use of both types of invertebrate sentinel prey. Fifty- seven papers used real prey, usually measuring predation on a focal （often pest） species, with studies overwhelmingly from North America. The median predation was 25.8% d-1. Artificial sentinel prey （45 papers） were used in both temperate and tropical areas, placed more above ground than at ground level. The most commonly used artificial prey imitated a caterpillar. Up to 14 predator groups were identified, registering a median of 8.8% d J predation; half the studies reported only bird predation. Predation on real prey was higher than on artificial ones, but invertebrate predation was not higher than vertebrate predation. Invertertebrate but not vertebrate predation was negatively related to prey size. Predation near the Equator was not higher than at higher latitudes, nor in cultivated than noncultivated habitats. The use of sentinel prey is not yet standardised in terms of prey size, arrangement, exposure period or data reporting. Due to the simplicity and ease of use of the method, such standardisation may increase the usefulness of comparative studies, contributing to the understanding of the importance and level of predation in various habitats worldwide.

关键词： arthropods artificial caterpillar biological control ecosystem service mortality top-down effects

Environmental filtering is the main assembly rule of ground beetles in the forest and its edge but not in the adjacent grassland

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Insect Science 2019年第1期26卷 154-163页

作者： Tibor Magura gabor L.Lovei Department of Ecology University of DebrecenDebrecenHungary Department of Agroecology Flakkebjerg Research Centre Aarhus UniversitySlagelseDenmark

In a fragmented landscape,transitional zones between neighboring habitats are common,and our understanding of community organizational forces across such habitats is *** studies are numerous,but the majority of them utilize information on species richness and *** and taxonomic diversity,however,provide little information on the functioning and phylogeny of the co-existing *** the evaluation of their functional and phylogenetic relationships,we aimed to assess whether ground beetle assemblages are deterministically or stochastically structured along grassland-forest *** results showed different community assembly rules on opposite sides of the forest *** the grassland,co-occurring species were functionally and phylogenetically not different from the random null model,indicating a random assembly *** to this,at the forest edge and the interior,co-occurring species showed functional and phylogenetic clustering,thus environmental filtering was the likely process structuring carabid *** assembly in the grassland was considerably affected by asymmetrical species flows (spillover)across the forest edge:more forest species penetrated into the grassland than open-habitat and generalist species entered into the *** asymmetrical species flow underlines the importance of the filter function of forest *** unfavorable,human-induced changes to the structure,composition and characteristics of forest edges may alter their filter function,edges have to be specifically considered during conservation management.

关键词： asymmetrical species flow coexisting species functional features phylogeny random process traits

The Effect of Reaction Conditions on the Synthesis of Thermoplastic Elastomers Containing Polyalloocimene, Polyisobutylene and Tapered Blocks

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Chinese Journal of Polymer Science 2019年第9期37卷 884-890页

作者： Jozsef Kantor Judit E. Puskas gabor Kaszas Department of Chemical and Biomolecular Engineering The University of Akron Akron OH 44325 USA Department of Food Agricultural and Biological Engineering (1/1/2019) The Ohio State University Wooster OH 44691 USA PolyFiberMatrix LLC 2295 W. Market St. Suite D. Akron OH 44313 USA

This work investigates the effect of reaction conditions on the copolymerization of isobutylene (IB) with alloocimene (Allo) in methyl chloride (MeCl) using AlCh and ethylaluminum dichloride (EtAlCh) as coinitiators and adventitious moisture as the initiator. Both AlCh and EtAlCb produced high molecular weight (Mn > 1.0 x 10^5 g/mol) thermoplastic elastomers (TPEs) with good mechanical properties in short reaction time (< 10 min). These unique TPEs have unsaturations in the end blocks, leading to easy functionalization and/or crosslinking.

关键词： Polyisobutylene Alloocimene Triblock copolymer Carbocationic polymerization