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Статті в журналах з теми "Reduced scale prototype"
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Chen, Ling, Xuan Wang, Baiyi Li, and Peng Lin. "Experimental Study of Scale Effect in Tunnel Fires at Different Sealing Ratios." Fire 6, no. 3 (February 28, 2023): 92. http://dx.doi.org/10.3390/fire6030092.
Повний текст джерелаАнотація:
Fully or partially sealing the openings of tunnels to accelerate the self-extinction of fires provides a promising firefighting tactic to beat large fires in a long tunnel. So far, most experimental studies on the characteristics of fire with different sealing ratios have been conducted in reduced-scale tunnels. However, whether the findings in a reduced-scale tunnel can be converted to its full-scale prototype tunnel based on scaling laws has not yet been adequately studied. A series of experiments with heat-release rates of 15.8, 31.6 and 63.2 kW were conducted with sealing ratios ranging from 0% to 100% in a prototype tunnel measuring 20 m long, 0.9 m wide and 0.46 m high. The experimental results were compared with those from a 1/2 reduced-scale tunnel measuring 10 m long, 0.45 m wide and 0.23 m high. It showed that temperature rise along the tunnel in the 1/2 reduced-tunnel could be significantly underestimated. The differences in temperature rise increased monotonously with distance away from the fire seat, and they were as high as 70% at the tunnel portals, irrespective of the heat-release rates and sealing ratios. The study showed that the scale effect of fires was not sensitive to the Reynolds number of flows in tunnels. The minimal sealing ratio for the self-extinction of fires in the prototype tunnel was 85%, whilst it was 75% in the 1/2 reduced-scale tunnel, and the study revealed that the fires were much easier to extinguish in the 1/2 reduced-scale tunnel than those in the prototype tunnel, where the fires can sustain in a lower oxygen concentration. The study demonstrated that scaling laws could be invalid for tunnel fires with different sealing ratios and that results observed in reduced-scale tunnels should be further verified when applied to full-scale prototypes.
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Cervelli, F., G. Chen, G. Coignet, S. Di Falco, E. Falchini, T. Lomtadze, Z. Liu, et al. "A reduced scale e.m. calorimeter prototype for the AMS-02 experiment." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 490, no. 1-2 (September 2002): 132–39. http://dx.doi.org/10.1016/s0168-9002(02)00915-4.
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Alpaslan, Emre. "Investigation on Similarity between Dynamic Behavior of a Reduced-Scale One Span Historical Masonry Arch Bridge Model and Prototype Bridge." Civil Engineering Beyond Limits 1, no. 1 (December 17, 2019): 5–11. http://dx.doi.org/10.36937/cebel.2020.001.002.
Повний текст джерелаАнотація:
Experimental investigations of large and complex structural systems can be carried out by reduced-scale models in terms of convenience, time-saving and economical. This can be applied to different fields of study such as vibration, impact and explosion problems in structural engineering and allows reliable analysis to understand the static and dynamic behavior of real structures called a prototype. This study aims that a 1/3 reduced-scale model is created in the laboratory environment considering similitude requirements by selecting a single span historical masonry arch bridge as a prototype structure. For this purpose, the Operational Modal Analysis (OMA) Technique is utilized for experimental study to determine modal parameters of the prototype and model bridges. The similarity of the dynamic behavior of the reduced-scale bridge model and prototype are investigated. The analysis of the similarity in the dynamic behavior of the prototype and model bridge consists of comparing the natural frequencies and mode shapes by utilizing the modal assurance criterion (MAC) corresponding to the translational, bending and torsional modes. As a result of the study, it is concluded that the dynamic behavior of the reduced-scale bridge model is similar to the dynamic behavior of the prototype bridge.
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Al-Hassawi, Omar Dhia, and David Drake. "Innovations in Passive Downdraft Cooling Performance Evaluation Methods: Design and Construction of a Novel Environmental Test Chamber." Energies 16, no. 11 (May 27, 2023): 4371. http://dx.doi.org/10.3390/en16114371.
Повний текст джерелаАнотація:
Energy demand for active mechanical space cooling is projected to double by 2050. Wider adoption of passive cooling systems can help reduce demand. However, familiarity with these systems remains low, and innovation in the field is constrained due to a lack of cost-effective, accessible performance evaluation methods. This paper reports the design, construction, and commissioning of an affordable, self-contained environmental test chamber. The novel chamber replicates a range of outdoor conditions common in hot, dry regions, making possible year-round testing of reduced-scale prototypes. Data from calibration testing are reported, showing no significant difference in evaporative efficiency when a reduced-scale prototype tested in the chamber is compared with datasets from prior full-scale testing. Analyzing the results using an independent sample two-tailed t-test with a 95% confidence interval found a p-value of 0.75. While measured outlet air velocities for reduced-scale and full-scale prototypes differed to some extent (root mean square error of 0.45 m/s), results were nevertheless deemed comparable due to errors introduced by the rapid change in wind speeds and directions at full scale. Future chamber modifications will correct misalignments between data collected from the two scales and prevent observed increases in the chamber’s relative humidity levels during testing.
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Stanciu, Alexandru Lucian, Nicoleta Pascu, Constantin Dogariu, and Cristina Mohora. "Researches regarding scale reduced models for the optimisation of the aerodynamic coefficient." MATEC Web of Conferences 290 (2019): 04011. http://dx.doi.org/10.1051/matecconf/201929004011.
Повний текст джерелаАнотація:
Within the lifecycle of the product, the reduced models are very important for the experimental validation of the prototype. The modelling, simulation and optimization stage precedes the prototype realization, being part of the computer aided design (CAD), computer aided engineering (CAE). The physical model is a physical layout or test setup that reproduces, on a small scale, the features of the original system, in our case the vehicle body layout. The paper presents an automobile reduced model, with the aim to study the aerodynamic theory. The paper presents the algorithms of conceptual design of the scale reduced model, namely: 3D modelling, small scale modelling technology and geometric shape optimization solutions using different CAD-CAE programs.
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Brigida, M., G. A. Caliandro, C. Favuzzi, P. Fusco, F. Gargano, N. Giglietto, F. Giordano, et al. "Beam test results with a reduced scale Silicon Transition Radiation Detector prototype." Nuclear Instruments and Methods in Physics Research Section A: Accelerators, Spectrometers, Detectors and Associated Equipment 577, no. 3 (July 2007): 519–22. http://dx.doi.org/10.1016/j.nima.2007.04.133.
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Tan, Xiao Jing, and Bin Wu. "Substructure Pseudo-Dynamic Testing of a Full-Scale Confined Masonry Building." Advanced Materials Research 250-253 (May 2011): 2566–70. http://dx.doi.org/10.4028/www.scientific.net/amr.250-253.2566.
Повний текст джерелаАнотація:
The seismic behavior of a single-story ten-bay confined masonry structure was investigated using substructure pseudo-dynamic tests. Only one bay of the prototype was regarded as the test model and the remainder was regarded as numerical model. The test results show that the test model withstood, with slight damage, strong earthquakes with peak ground acceleration of 1600 gal. It is found that prototypes of the tested type exhibited satisfactory seismic performance. Hence, the confinement can be reduced if the budget of the building is limited.
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Chen, Jian Yun, Lin Qiang Ji, Qiang Xu, and Jing Li. "Numerical Verification of Brittle Material Failure Model Test." Applied Mechanics and Materials 405-408 (September 2013): 2053–56. http://dx.doi.org/10.4028/www.scientific.net/amm.405-408.2053.
Повний текст джерелаАнотація:
The failure shaking table model test of mass concrete structures is an important basis for understanding to the actual failure of structures. This paper derived all kinds of similar scales between model and prototype in nonlinear dynamic shaking table test, and constructed the reduced scale nonlinear numerical simulation model. The numerical results show that the failure of model and prototype matches the nonlinear similarity theory. Besides, the effect of the characteristics of ground motion was studied and it cannot be ignored to ensure the accuracy of the test.
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Esmaeili, Taymaz, Tetsuya Sumi, Sameh A. Kantoush, and Yoji Kubota. "Free-Flow Sediment Flushing: Insights from Prototype-Scale Studies." Journal of Disaster Research 13, no. 4 (August 1, 2018): 677–90. http://dx.doi.org/10.20965/jdr.2018.p0677.
Повний текст джерелаАнотація:
Free-flow sediment flushing operation offers viable means to preserve the storage capacity of dam reservoirs as the incoming flood erodes the flushing channel, and the deposited sediment is flushed from the reservoir. This method involves complex flow patterns and flushing channel formation procedures owing to the dynamic interaction between varying flow conditions (e.g., shallow and deep flows) and moveable bed variations notably when the non-uniform sediments exist in the complex geometry of reservoirs. In the present study, first, the numerical simulation of a previously conducted free-flow sediment flushing operation in the Dashidaira and the target segment of Unazuki reservoirs using the available field-measured data were presented. Then, to improve the flushing efficiency in the Dashidaira reservoir, the effects of using a groyne were studied. A fully 3D numerical model using the finite volume method in combination with a wetting/draying algorithm was utilized to reproduce the flow velocity field and morphological bed changes. While the characteristics of the flow field can be captured by the numerical model in Dashidaira and Unazuki reservoirs, simulated bed changes in upstream areas covered with the coarser materials (e.g., study zone of Unazuki reservoir) showed some discrepancies. The outcomes also revealed that implementing a groyne at the entrance of the wide midstream of Dashidaira reservoir can locally increase the sediment erosion chance from this area and thereby can improve the flushing efficiency by approximately 10%. Therefore, the risks associated with the accumulation of distorted sediments in the wide midstream of Dashidaira reservoir within a long-term period could be reduced.
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Cirpici, Burak Kaan. "Predicting and comparing the fire performance of a small-scale composite structure." Challenge Journal of Concrete Research Letters 12, no. 3 (September 15, 2021): 72. http://dx.doi.org/10.20528/cjcrl.2021.03.001.
Повний текст джерелаАнотація:
The purpose of this paper is to investigate a strategy for the fire testing of reduced scale structural models which will help engineers design safer structures and reduce the loss from fires. The concept of this work is how composite frame floor arrangements, beam-column connections might be modelled at a small scale suitable for fire testing. Testing full-scale is expensive, besides the testing of scaled model produces reasonable results which help us to understand the failure mechanism and all significant thermo-structural responses involved in a fire. Thermal effects within a structural element generate fire curve, thermal input and structural displacement output, in other words cause and impact. Dimensional analysis, which is a condition for dynamic similarity between prototype and model, can be achieved when all the dimensionless groups are set equal for both model and prototype. On the other hand, scaling rules are used to decide how much insulating material will be used on a structure. 5-storey composite building with composite floors and steel columns has been modelled at small scale with 1/5. The obtained results from various parametric investigations show that the reduced scale model fire test method would be a feasible way to investigate the fire performance of composite structures.
Дисертації з теми "Reduced scale prototype"
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Stallings, Brad L. "Design of a ship service converter module for a reduced-scale prototype integrated power system." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.navy.mil/100.2/ADA392078.
Повний текст джерелаАнотація:
Thesis (M.S. in Electrical Engineering) Naval Postgraduate School, December 2001.Thesis advisor(s): Ciezki, John G. ; Ashton, Robert W. "December 2001." Includes bibliographical references (p. 201-202). Also available in print.
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Whitcomb, Bryan D. "Design and implementation of a high-power resonant DC-DC converter module for a reduced-scale prototype integrated power system." Thesis, Monterey, Calif. : Springfield, Va. : Naval Postgraduate School ; Available from National Technical Information Service, 2001. http://handle.dtic.mil/100.2/ADA430967.
Повний текст джерелаАнотація:
Thesis (Electrical Engineer)--Naval Postgraduate School, September 2001.Thesis Advisor(s): Robert W. Ashton, John G. Ciezki, Todd R. Weatherford. Includes bibliographical references (p. 175-177). Also available online.
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Ratovonkery, Julie. "DYNABIOSOL : Conception bio-inspirée d'une enveloppe solaire Photovoltaïque dynamique aux fonctionnalités évolutives." Electronic Thesis or Diss., Chambéry, 2023. http://www.theses.fr/2023CHAMA027.
Повний текст джерелаАнотація:
L'urgence climatique, l'augmentation de demandes énergétiques et l'épuisement de ressources fossiles ont mené à des ambitions énergétiques et environnementales de plus en plus élevées. Dans le secteur de bâtiment, ces ambitions visent à des bâtiments résilients, durables, à faible impact environnemental et à énergie positive. L'innovation de l'enveloppe du bâtiment, qui est un élément clé de son efficacité énergétique, est donc primordiale. En effet, l'enveloppe est souvent conçue sur des bases de fonctionnalités statiques. Pourtant, elle devrait être comme une interface adaptative et multifonctionnelle, qui échange et exploite les effets de son environnement, afin d'assurer la qualité des ambiances intérieures et la production d'énergie de fonctionnement du bâtiment.Dans ce contexte, cette thèse consiste à la conception d'une facade adaptative à composants photovoltaïques (PV) intégrés. Les fonctionnalités adaptives sont visées tant pour l'amélioration de sa performance thermique que pour la maximisation de la production électrique des modules photovoltaïques. L'obtention d'un élément d'enveloppe, muni de fonctionnalités dynamiques et adaptatives, fait souvent recours à des systèmes mécaniques et de contrôles complexes. Pour cette raison, une approche de bioinspiration et l'utilisation des matériaux intelligents sont choisies pour obtenir des mécanismes d'adaptation flexibles et intelligemment low-tech.L'approche consiste à l'analyse thermique et électrique d'une facade photovoltaïque de base. Dans notre étude, elle est composée de modules PV bifaciaux, d'une lame d'air ventilée et d'un mur multicouche. Le principe est d'identifier des propriétés limitant cette facade à des fonctionnalités statiques. De cette manière, les êtres vivants en lien avec les propriétés identifiées et pouvant franchir ses limitations sont explorés. Par la suite, les matériaux intelligents pouvant assurer les stratégies bioinspirées sont sélectionnés afin de développer le nouveau concept. Enfin, la solution est validée grâce à des études expérimentales sur les échantillons de composants intelligents choisis et sur un prototype à échelle réduite de la facade. Des études numériques de faisabilité et d'analyse de performance énergétique à l'échelle du bâtiment sont également réalisées.Cette démarche a conduit à l'application de composants de bilames thermosensibles et réfléchissants sur le mur derrière les modules PV. Les bilames, en forme de lamelle rectangulaire sont disposés sur le mur en face des cellules PV. Lorsque la température augmente, ils fléchissent progressivement. Leur déformation cyclique permet d'ajuster les fonctionnalités de la facade suivant trois principes. Premièrement, en été, la facade photovoltaïque se rafraichit grâce à l'ombrage du mur et à la dissipation de chaleur par augmentation progressive de surface d'échange dans la lame d'air. Deuxièmement, en hiver, l'énergie solaire thermique est collectée soit en fermant la lame d'air ou par la valorisation de l'air préchauffée. Enfin, la production électrique des modules PV est optimisée grâce à la réflexion des rayons solaires vers la face arrière des modules bifaciaux par les bilames. Les études expérimentales et numériques réalisées ont permis de valider le potentiel du concept pour l'amélioration de l'efficacité énergétique, surtout pour l'augmentation de la production d'électricité et la performance thermique en étéClimate change, growing energy demand and depletion of fuel resources have led to increasingly high energy and environmental ambitions. These ambitions aim for resilient, sustainable, zero carbon and positive energy buildings in the building sector. Radical innovation in building envelope technologies is paramount as it is a key element in building energy efficiency. Indeed, the envelope is often designed on the basis of static functionalities rather than an adaptive and multifunctional interface. However, in the latter case, it would interact with and benefit from the effects of its external environment to ensure a comfortable indoor environment and the production of the building operating energy.In this context, this thesis consists in the design of an adaptive facade with integrated photovoltaic (PV) components. The adaptive functionalities are developed to improve both the thermal performance of the facade and the electrical production of the PV modules. Designing such an envelope element often requires complex mechanical and control systems to implement dynamic and adaptive functionalities. For this reason, we have chosen to adopt a bioinspiration approach and use smart materials to achieve flexible and low-tech adaptation mechanisms.The methodology involves the analysis of the thermal and electrical behaviour of a standard photovoltaic facade. In our case, it comprises bifacial PV modules, a ventilated air gap and a multilayer wall. The principle is to identify the properties limiting that facade to static functionalities. From this step, biological mechanisms related to the identified properties, and that can overcome the limitations are explored. Afterwards, smart materials enabling to implement the bioinspired strategies are selected. Finally, the outline of the new concept is developed with the principles involved. The solution is validated through experimental studies on the samples of the selected materials and on a reduced-scale prototype of the facade. Numerical feasibility studies and energy performance analysis at the building scale are also carried out.The developed solution consists in the application of thermosensitive and reflective bilayer components on the wall behind the PV modules. Those components are thin rectangular slats applied opposite to the PV cells. When the temperature rises, they gradually bend. Their cyclic deformation allows the adjustment of the facade functionalities according to three principles. First, in summer, the PV facade is cooled by shading the wall and dissipating heat through the increased thermal surface exchange in the air gap. Second, in winter, solar thermal energy is harvested by closing the air gap or recovering preheated air. Finally, the bilayers enhance the PV power output because of their high reflection of the irradiance to the backside of the bifacial PV modules. The experimental and numerical studies have validated the potential of the design to improve building energy efficiency, especially for increasing yearly electricity production and thermal performance in summer
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Jaber, Jana. "Application de la fabrication additive à la modélisation physique des joints et des massifs rocheux, par approches expérimentales et numériques." Electronic Thesis or Diss., Université de Lorraine, 2020. http://www.theses.fr/2020LORR0071.
Повний текст джерелаАнотація:
Cette thèse présente une étude de l’application de la fabrication additive (connue sous le nom d’impression 3D) à la mécanique des roches. Elle s’inscrit dans le cadre d’un projet plus large visant à construire un modèle physique de 2m3 d’un massif rocheux explicitement discontinu, dont le comportement est contrôlé principalement par les discontinuités. La technique de fabrication additive adoptée est le frittage laser (SLS), le matériau utilisé est un polymère : le polyamide 12 (PA12). Dans un premier temps des joints artificiels construits par SLS sont testés sous essais de cisaillement à contrainte normale constante. Deux familles de discontinuités sont étudiées. La première est formée par des joints à géométrie simplifiée (joints planaires ou en dents de scies) ayant une ouverture de 0,4mm et contenant des ponts rocheux. Les résultats montrent que cette technique de fabrication des joints en PA12 permet d’obtenir un comportement global similaire à celui des joints rocheux naturels, avec une cohésion pilotée par les ponts rocheux, et un angle de frottement dépendant de l’angle des aspérités. La deuxième famille est constituée de joints ayant des rugosités plus réalistes, auxquelles on peut attribuer une valeur de JRC, communément utilisée pour décrire les joints naturels. Cette configuration permet elle aussi de reproduire un comportement global équivalent à celui des joints naturels, avec une mobilisation des aspérités primaires et secondaires des surfaces. Les résultats obtenus sont comparés au critère de rupture de Barton-Bandis. Cette étude expérimentale est complétée par une modélisation numérique sous le logiciel UDEC, dans le but d’étudier la capacité des modèles existants à reproduire le comportement des joints artificiels obtenu expérimentalement, et de calibrer numériquement les paramètres mécaniques utilisés dans la modélisation pour représenter les essais expérimentaux. Dans un second temps, des éprouvettes cylindriques (16 x 32 cm) contenant deux ou huit discontinuités à géométrie simplifiée (planaire + ponts rocheux) sont fabriquées et testées sous compression uni-axiale. Il s’agit d’une première tentative d’un modèle réduit explicitement discontinu et contenant des joints ayant un comportement mécanique contrôlé. Les résultats permettent de mettre l’accent sur l’influence des discontinuités sur le comportement global d’un massif rocheux. Ces essais sont comparés à une modélisation numérique sous 3EDC. Finalement, et afin d’étudier l’applicabilité de cette technique à la modélisation physique, les lois de similitudes sont appliquées aux résultats obtenus dans les parties précédentes. Il en ressort qu’il est possible d’utiliser la SLS et le PA12 en modélisation physique des massifs rocheux, jusqu’un facteur d’échelle sur les dimensions métriques de 1/25This thesis presents a study of the application of additive manufacturing (known as 3D printing) to rock mechanics. It is part of a larger project aimed at building a 2m3 physical model of an explicit discontinuous rock mass, whose behaviour is mainly controlled by discontinuities. The 3DP technology adopted in this work is selective laser sintering, and the material is Polyamide 12. First, we present the experimental results of the mechanical characterization of artificial rock joints constructed by 3DP. Two joint families are tested. The first is characterized by a fixed aperture (0,4mm), a simplified geometry (planar or sawtooth), and containing rock bridges. The mechanical characterization shows that these joints exhibit a mechanical behavior similar to that of natural rock joints under shear tests, with a cohesion driven by the rock bridges, and a friction angle which depends on the angle of the asperities. The second family consists of joints with more realistic roughnesses, to which a JRC value, commonly used to describe natural joints, can be assigned. Again, experimental results show the potential of artificial joints to reproduce the mechanical behavior of natural joints, and to respect the Barton-Bandis criterion. Experimental studies are coupled with numerical modeling, using the UDEC software, to define the appropriate model that reproduces the experimental results, and to calibrate the mechanical parameters of both joints type. After defining different artificial joints with controlled parameters, cylindrical samples (16 x 32 cm) containing two and eight planar discontinuities with rock bridges are printed and tested under uni-axial compression. This is a first attempt at an explicitly discontinuous physical model containing joints with controlled mechanical behaviour. The mechanical behavior of these samples highlights the influence of discontinuities in controlling the global behavior and resistance of rock masses. The results are then compared to a numerical modeling under 3EDC. Finally, scaling laws are applied to the previous results. The application of scale factors to the experimental results shows the possibility of representing natural rock mass and rock joints with artificial 3DP joints (SLS technique) up to a scale factor on metric dimensions of 1/25
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Beeny, Bradley Aaron 1988. "Thermal Hydraulic Analysis of a Reduced Scale High Temperature Gas-Cooled Reactor Test Facility and its Prototype with MELCOR." Thesis, 2012. http://hdl.handle.net/1969.1/148182.
Повний текст джерелаАнотація:
Pursuant to the energy policy act of 2005, the High Temperature Gas-Cooled Reactor (HTGR) has been selected as the Very High Temperature Reactor (VHTR) that will become the Next Generation Nuclear Plant (NGNP). Although plans to build a demonstration plant at Idaho National Laboratories (INL) are currently on hold, a cooperative agreement on HTGR research between the U.S. Nuclear Regulatory Commission (NRC) and several academic investigators remains in place.
One component of this agreement relates to validation of systems-level computer code modeling capabilities in anticipation of the eventual need to perform HTGR licensing analyses. Because the NRC has used MELCOR for LWR licensing in the past and because MELCOR was recently updated to include gas-cooled reactor physics models, MELCOR is among the system codes of interest in the cooperative agreement. The impetus for this thesis was a code-to-experiment validation study wherein MELCOR computer code predictions were to be benchmarked against experimental data from a reduced-scale HTGR testing apparatus called the High Temperature Test Facility (HTTF). For various reasons, HTTF data is not yet available from facility designers at Oregon State University, and hence the scope of this thesis was narrowed to include only computational studies of the HTTF and its prototype, General Atomics’ Modular High Temperature Gas-Cooled Reactor (MHTGR). Using the most complete literature references available for MHTGR design and using preliminary design information on the HTTF, MELCOR input decks for both systems were developed. Normal and off-normal system operating conditions were modeled via implementation of appropriate boundary and inititial conditions. MELCOR Predictions of system response for steady-state, pressurized conduction cool-down (PCC), and depressurized conduction cool-down (DCC) conditions were checked against nominal design parameters, physical intuition, and some computational results available from previous RELAP5-3D analyses at INL.
All MELCOR input decks were successfully built and all scenarios were successfully modeled under certain assumptions. Given that the HTTF input deck is preliminary and was based on dated references, the results were altogether imperfect but encouraging since no indications of as yet unknown deficiencies in MELCOR modeling capability were observed. Researchers at TAMU are in a good position to revise the MELCOR models upon receipt of new information and to move forward with MELCOR-to-HTTF benchmarking when and if test data becomes available.
Книги з теми "Reduced scale prototype"
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Design of a Ship Service Converter Module for a Reduced-Scale Prototype Integrated Power System. Storming Media, 2001.
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Design and Implementation of a High-Power Resonant DC-DC Converter Module for a Reduced-Scale Prototype Integrated Power System. Storming Media, 2001.
Знайти повний текст джерелаЧастини книг з теми "Reduced scale prototype"
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Jodin, G., M. Carvalho, C. Raibaudo, C. Döll, P. Mouyon, P. Doerffer, P. Flaszynski, et al. "Reduced Scale Prototype Morphing Achievements in Subsonic and Transonic Regimes." In Notes on Numerical Fluid Mechanics and Multidisciplinary Design, 13–45. Cham: Springer International Publishing, 2023. http://dx.doi.org/10.1007/978-3-031-22580-2_2.
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Boyter-Grant, Kelton, Zhouyang Xin, Ding Wen Bao, Xin Yan, and Dan Luo. "Weaving Tectonics: Algorithmically Optimised Robotic FRP Weaving of Large Scale Planar Forms." In Computational Design and Robotic Fabrication, 466–75. Singapore: Springer Nature Singapore, 2024. http://dx.doi.org/10.1007/978-981-99-8405-3_39.
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AbstractSteel reinforced concrete is a widely used material for constructing large spanning planar building elements due to its strength, durability, and low cost, but its environmental impact, long fabrication time, and relatively low structural performance demonstrate the need for innovation. To address these issues, this study proposes a novel design methodology and fabrication method that integrates robotic Fibre Reinforced Polymer (FRP) woven reinforcement that is optimized using a Multi-Weight Bi-directional Evolutionary Structural Optimization (MW-BESO) algorithm. The optimized FRP reinforcement is then cast in epoxy resin to produce the large scale planar building element. The methodology is evaluated through a Tabletop prototype and other small-scale rapid prototypes, which demonstrate the successes, challenges, and limitations of this approach. The study outlines the material and methodological testing conducted to assess the effectiveness of using the MW-BESO algorithm with robotic FRP weaving and describes the workflow of transforming the resulting 3D MW-BESO geometry into a 2D robotic winding path for fabrication. The research shows that this methodology has the potential to reduce the environmental impact, stimulate innovative design solutions, and streamline the fabrication of large scale building elements, providing a promising avenue for the development of sustainable and efficient construction techniques.
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Malavena, Gerardo. "Modeling of GIDL–Assisted Erase in 3–D NAND Flash Memory Arrays and Its Employment in NOR Flash–Based Spiking Neural Networks." In Special Topics in Information Technology, 43–53. Cham: Springer International Publishing, 2022. http://dx.doi.org/10.1007/978-3-030-85918-3_4.
Повний текст джерелаАнотація:
AbstractSince the very first introduction of three-dimensional (3–D) vertical-channel (VC) NAND Flash memory arrays, gate-induced drain leakage (GIDL) current has been suggested as a solution to increase the string channel potential to trigger the erase operation. Thanks to that erase scheme, the memory array can be built directly on the top of a $$n^+$$ n + plate, without requiring any p-doped region to contact the string channel and therefore allowing to simplify the manufacturing process and increase the array integration density. For those reasons, the understanding of the physical phenomena occurring in the string when GIDL is triggered is important for the proper design of the cell structure and of the voltage waveforms adopted during erase. Even though a detailed comprehension of the GIDL phenomenology can be achieved by means of technology computer-aided design (TCAD) simulations, they are usually time and resource consuming, especially when realistic string structures with many word-lines (WLs) are considered. In this chapter, an analysis of the GIDL-assisted erase in 3–D VC nand memory arrays is presented. First, the evolution of the string potential and GIDL current during erase is investigated by means of TCAD simulations; then, a compact model able to reproduce both the string dynamics and the threshold voltage transients with reduced computational effort is presented. The developed compact model is proven to be a valuable tool for the optimization of the array performance during erase assisted by GIDL. Then, the idea of taking advantage of GIDL for the erase operation is exported to the context of spiking neural networks (SNNs) based on NOR Flash memory arrays, which require operational schemes that allow single-cell selectivity during both cell program and cell erase. To overcome the block erase typical of nor Flash memory arrays based on Fowler-Nordheim tunneling, a new erase scheme that triggers GIDL in the NOR Flash cell and exploits hot-hole injection (HHI) at its drain side to accomplish the erase operation is presented. Using that scheme, spike-timing dependent plasticity (STDP) is implemented in a mainstream NOR Flash array and array learning is successfully demonstrated in a prototype SNN. The achieved results represent an important step for the development of large-scale neuromorphic systems based on mature and reliable memory technologies.
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Soares, Ana Caroline Meireles, Jhonatan Peres de Sousa, Gielson Vitor Oliveira, Rivânia da Silva Lira, and Josimar Hendrio Ferraz Borges. "Development of an automated greenhouse for plants." In DEVELOPMENT AND ITS APPLICATIONS IN SCIENTIFIC KNOWLEDGE. Seven Editora, 2023. http://dx.doi.org/10.56238/devopinterscie-173.
Повний текст джерелаАнотація:
This project proposes the development of a didactic plant (greenhouse) for monitoring and automating the variables of temperature, humidity, and luminosity through the Arduino, aiming at the development of a plant in a protected environment and on a reduced scale. As a project methodology, an automated prototype for greenhouses based on the Arduino platform was implemented, which receives information from the sensors and compares it with the pre-selected parameters, making it always follow the established measures for the good development of the crop in question. It is concluded that the simulations produced are fundamental to verify the response mode of the didactic plant in different conditions, chosen materials, and worked parameters, as well as allowing to guide the research group, regarding the ideal conditions for the development of the plant. Studies of this nature enable the development of domestic greenhouses combined with automation techniques, in addition to making plant production accessible and efficient in small-scale protected environments.
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Deng, Yasi, Siyuan Leng, Songlin Li, and Yangqing Liu. "Effect Factors of Seismic Hydrodynamic Pressure on a Bridge Tower of a Deep-Water Cable-Stayed Bridge." In Advances in Transdisciplinary Engineering. IOS Press, 2023. http://dx.doi.org/10.3233/atde230828.
Повний текст джерелаАнотація:
Experimental study on effect factors of seismic hydrodynamic pressure on a bridge tower of a deep-water cable-stayed bridge located in Western China is reported in this manuscript. The effect factors include water levels, seismic ground accelerations and water environment surrounding the tower (reflected waves and inner water). Effects of these factors on the hydrodynamic pressure were investigated through reduced-scale shaking table tests with the boundary conditions close to those of the prototype tower. Parametric comparisons are made among the test results. Also, the calculation values of the current Chinese and Japanese standards are compared to the test results. The study results show that the hydrodynamic pressure significantly increased as the water level or the magnitude of the seismic wave increased. The water environment (reflected waves and inner water) had a mild effect on the hydrodynamic pressure. Both of the standards are found to overestimate the hydrodynamic pressure. Calculation methods with less simplification and higher precision is of significant necessity in engineering practice.
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Li, Qiong, Wangling Yu, and H. Henry Zhang. "Modeling, Model Reduction, and Control of a Hands-Free Two-Wheeled Self-Balancing Scooter." In Advanced Robotics and Intelligent Automation in Manufacturing, 185–202. IGI Global, 2020. http://dx.doi.org/10.4018/978-1-7998-1382-8.ch007.
Повний текст джерелаАнотація:
Designing a two-wheeled self-balancing scooter involves in the synergistic approach of multidisciplinary engineering fields with mutual relationships of power transmission, mass transmission, and information transmission. The scooter consists of several subsystems and forms a large-scale system. The mathematical models are in the complex algebraic and differential equations in the form of high dimension. The complexity of its controller renders difficulties in its realization due to the limit of iteration period of real time control. Routh model reduction technique is employed to convert the original high-dimensional mathematical model into a simplified lower dimensional form. The modeling is derived using a unified variational method for both mechanical and electrical subsystems of the scooter, and for the electronic components equivalent circuit method is adopted. Simulations of the system response are based on the reduced model and its control design. A prototype is developed and realized with Matlab-Labview simulation and control environment.
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"Advances in Fish Tagging and Marking Technology." In Advances in Fish Tagging and Marking Technology, edited by Tom F. Shardlow and Kim D. Hyatt. American Fisheries Society, 2012. http://dx.doi.org/10.47886/9781934874271.ch33.
Повний текст джерелаАнотація:
<i>Abstract</i>.—A micro-controlled fish tag which records post-tagging lifespan was developed, tested as a prototype, and then evaluated in field applications for measuring survey life. The method of constructing the Tilt-Tag and the results of tank test trials on Chinook salmon <i>Oncorhynchus tshawytscha</i>, preliminary field trials on chum salmon <i>Oncorhynchus keta </i>are reviewed, and full-scale field applications on sockeye salmon <i>Oncorhynchus nerka </i>are presented. Survey life (SL) is an essential component for area-under-the-curve (AUC) estimation of Pacific salmon <i>Oncorhynchus </i>spp. spawning escapements. However, direct estimates of SL are often unavailable because the estimates mostly require extensive and costly tag-recapture programs. In this study, the Tilt-Tag was used to estimate SL by measuring the elapsed time from tagging until the fish came to rest permanently on its lateral or dorsal surface. Tilt-Tag derived estimates of SL, combined with specification of survey rules that were based on historical run-timing and stream temperature, reduced survey costs by approximately 50% when compared to conventional tag-recapture methods. Abridged details on how to construct the Tilt-Tag are provided so that researchers will be able to make their own tags.
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Yu, Ruiguo, Yihang Zhao, Mei Yu, Jie Gao, Chenhan Wang, Ruixuan Zhang, and Xuewei Li. "Region-Specific Prototype Customization for Weakly Supervised Semantic Segmentation." In Frontiers in Artificial Intelligence and Applications. IOS Press, 2023. http://dx.doi.org/10.3233/faia230608.
Повний текст джерелаАнотація:
It is well known that weakly supervised semantic segmentation requires only image-level labels for training, which greatly reduces the annotation cost. In recent years, prototype-based approaches, which prove to substantially improve the segmentation performance, have been favored by a wide range of researchers. However, we are surprised to find that there are semantic gaps between different regions within the same object, hindering the optimization of prototypes, so the traditional prototypes can not adequately represent the entire object. Therefore, we propose region-specific prototypes to adaptively describe the regions themselves, which alleviate the effect of semantic gap by separately obtaining prototypes for different regions of an object. In addition, to obtain more representative region-specific prototypes, a plug-and-play Spatially Fused Attention Module is proposed for combining the spatial correlation and the scale correlation of hierarchical features. Extensive experiments are conducted on PASCAL VOC 2012 and MS COCO 2014, and the results show that our method achieves state-of-the-art performance using only image-level labels.
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Huang, Wei-Chih, and William J. Knottenbelt. "Low-Overhead Development of Scalable Resource-Efficient Software Systems." In Advances in Systems Analysis, Software Engineering, and High Performance Computing, 81–105. IGI Global, 2014. http://dx.doi.org/10.4018/978-1-4666-6026-7.ch005.
Повний текст джерелаАнотація:
As the variety of execution environments and application contexts increases exponentially, modern software is often repeatedly refactored to meet ever-changing non-functional requirements. Although programmer effort can be reduced through the use of standardised libraries, software adjustment for scalability, reliability, and performance remains a time-consuming and manual job that requires high levels of expertise. Previous research has proposed three broad classes of techniques to overcome these difficulties in specific application domains: probabilistic techniques, out of core storage, and parallelism. However, due to limited cross-pollination of knowledge between domains, the same or very similar techniques have been reinvented all over again, and the application of techniques still requires manual effort. This chapter introduces the vision of self-adaptive scalable resource-efficient software that is able to reconfigure itself with little other than programmer-specified Service-Level Objectives and a description of the resource constraints of the current execution environment. The approach is designed to be low-overhead from the programmer's perspective – indeed a naïve implementation should suffice. To illustrate the vision, the authors have implemented in C++ a prototype library of self-adaptive containers, which dynamically adjust themselves to meet non-functional requirements at run time and which automatically deploy mitigating techniques when resource limits are reached. The authors describe the architecture of the library and the functionality of each component, as well as the process of self-adaptation. They explore the potential of the library in the context of a case study, which shows that the library can allow a naïve program to accept large-scale input and become resource-aware with very little programmer overhead.
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M., Balamurugan, Raghu N., Kamala N., Trupti V. Nandikolmath, and Sarat Kumar Sahoo. "Solar Powered Electric Vehicle Through Wireless Power Transfer." In Electric Vehicles and the Future of Energy Efficient Transportation, 219–42. IGI Global, 2021. http://dx.doi.org/10.4018/978-1-7998-7626-7.ch009.
Повний текст джерелаАнотація:
Solar powered wireless electric vehicle charging technology functions independently without interface with the utility grid. Wireless power transfer (WPT) technology is incorporated for wireless charging, which brings the benefits of safe operation, less pollution, and little maintenance cost. WPT technology necessitates no physical connection between the charging device and vehicle, thus hazards and inconvenience produced by conventional charging methods have been minimized. WPT in electric vehicle can be used to reduce the charging time, range, and cost. In this chapter, the various configurations of WPT like inductive, capacitive, resonant, and roadway power transfer techniques have been presented. The small-scale prototype of wireless charging has been developed in the laboratory by incorporating inductive power transfer technique. The experimental results have been presented to validate the feasibility of the system in real time.
Тези доповідей конференцій з теми "Reduced scale prototype"
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Shen, Xiaobo, Weiwei Liu, Yong Luo, Yew-Soon Ong, and Ivor W. Tsang. "Deep Discrete Prototype Multilabel Learning." In Twenty-Seventh International Joint Conference on Artificial Intelligence {IJCAI-18}. California: International Joint Conferences on Artificial Intelligence Organization, 2018. http://dx.doi.org/10.24963/ijcai.2018/371.
Повний текст джерелаАнотація:
kNN embedding methods, such as the state-of-the-art LM-kNN, have shown impressive results in multi-label learning. Unfortunately, these approaches suffer expensive computation and memory costs in large-scale settings. To fill this gap, this paper proposes a novel deep prototype compression, i.e., DBPC for fast multi-label prediction. DBPC compresses the database into a small set of short discrete prototypes, and uses the prototypes for prediction. The benefit of DBPC comes from two aspects: 1) The number of distance comparisons are reduced in the prototype; 2) The distance computation cost is significantly decreased in the reduced space. We propose to jointly learn the deep latent subspace and discrete prototypes within one framework. The encoding and decoding neural networks are employed to make deep discrete prototypes well represent the instances and labels. Extensive experiments on several large-scale datasets demonstrate that DBPC achieves several orders of magnitude lower storage and prediction complexity than state-of-the-art multi-label methods, while achieving competitive accuracy.
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Zhou, Biao, Haotian Liang, Hui Miao, and Chaoping Zang. "Reduced-Scale Model Design for a High-Speed Rotor System Based on Similitude Theory." In ASME Turbo Expo 2019: Turbomachinery Technical Conference and Exposition. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/gt2019-91112.
Повний текст джерелаАнотація:
Abstract Reduced-scale models are often established based on similitude theory as an alternative to the direct experimental observation on the prototype, which is usually oversized or requires unacceptable expenses. Much insight into the similitude theory applied to various fields in structural engineering, vibration and impact problems has been gained to date. However, the efficient dynamic similarity design of complex rotors remains elusive. This paper is devoted to developing a reduced-scale model based on similitude theory from a high-speed rotor system prototype. Three critical speeds within the range of operating speeds characterize this flexible rotor. A reduced scaling design strategy for the complex rotor system is proposed as a two-step scheme. Similarity conditions relating the critical design parameters (such as rotor geometry, support stiffness, etc.) between the reduced-scale model and the prototype are derived. The scaling factors are accordingly determined by a dimensional analysis in combination with the governing equation of rotordynamics. This leads to a downsized rotor model with distorted geometric configuration whose operation speed is efficiently narrowed down. Dynamic similitude is assured by proportionally scaling down the three critical speeds while the rotor mode shapes still maintain high correlation between the prototype and downscaled model. The resultant reduced-scale model of the rotor system will practically guide the construction of the essential part of a whole engine dynamics test rig for laboratory use.
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Leonard, Daniel J., and Jules W. Lindau. "Multiphase Computation of Cavitation Breakdown in Model and Prototype Scale Francis Turbines." In ASME/JSME/KSME 2015 Joint Fluids Engineering Conference. American Society of Mechanical Engineers, 2015. http://dx.doi.org/10.1115/ajkfluids2015-5123.
Повний текст джерелаАнотація:
Steady-periodic multiphase Computational Fluid Dynamics (CFD) simulations were conducted to capture cavitation breakdown in a Francis hydroturbine due to large-scale vaporous structures. A reduced-scale model and a full-scale prototype were investigated to display differences in vapor content and machine performance caused by lack of Reynolds and Froude similarity. The model scale efficiencies compared favorably (within 3%) to the experimental cavitation tests. The CFD model and prototype displayed distinct qualitative and quantitative differences as σ was reduced. A stage-by-stage analysis was conducted to assess the effect of cavitation on loss distribution throughout the machine. Furthermore, a formal mesh refinement study was conducted on efficiency and volume of vapor, with three mesh levels and Richardson extrapolation, to ensure convergence.
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Gao, Jiancai, and Haixiao Liu. "CFD Analysis on Similarity Criteria of Hydrodynamic Characteristics for Gravity-Installed Anchors." In ASME 2019 38th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2019. http://dx.doi.org/10.1115/omae2019-95960.
Повний текст джерелаАнотація:
Abstract For reduced-scale model tests of gravity-installed anchors (GIAs), it is of great significance to extrapolate the testing results to prototype. This highlights the necessity of investigation of similarity criteria. The present work aims to find the similarity criteria of three prioritized hydrodynamic characteristics including VT, HP, and Cd for GIAs during installation in water through CFD simulations. In the present study, free falling processes of different reduced-scale T98 anchor models and prototype anchor is simulated, from which VT, HP, and Cd are extracted and analyzed to get the fitting curves for these three characteristics over reduced-scale λ. Based on these curves, hydrodynamic characteristics for prototype and other reduced-scale model can be extrapolated from model testing results. And, the researching procedure in this paper sets an example and reference to study about similarity criteria for other hydrodynamic characteristics.
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Roberts, Heather, Mitch Favrow, Jesse Coatney, David Yoe, Chenaniah Langness, and Christopher Depcik. "Small Scale Prototype Biomass Drying System for Co-Combustion With Coal." In ASME 2013 International Mechanical Engineering Congress and Exposition. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/imece2013-62188.
Повний текст джерелаАнотація:
Thermoelectric power plants burn thousands of tons of non-renewable resources every day to heat water and create steam, which drives turbines that generate electricity. This causes a significant drain on local resources by diverting water for irrigation and residential usage into the production of energy. Moreover, the use of fossil reserves releases significant amounts of greenhouse and hazardous gases into the atmosphere. As electricity consumption continues to grow and populations rise, there is a need to find other avenues of energy production while conserving water resources. Co-combusting biomass with coal is one potential route that promotes renewable energy while reducing emissions from thermoelectric power plants. In order to move in this direction, there is a need for a low-energy and low-cost system capable of drying materials to a combustion appropriate level in order to replace a significant fraction of the fossil fuel used. Biomass drying is an ancient process often involving the preservation of foods using passive means, which is economically efficient but slow and impractical for large-scale fuel production. This effort, accomplished as an undergraduate capstone design project, instead implements an active drying system for poplar wood using theorized waste heat from the power plant and potentially solar energy. The use of small-scale prototypes demonstrate the principles of the system at a significantly reduced cost while allowing for calculation of mass and energy balances in the analysis of drying time, Coefficient of Performance, and the economics of the process. Experimental tests illustrate the need to distribute air and heat evenly amongst the biomass for consistent drying. Furthermore, the rotation of biomass is critical in order to address the footprint of the system when placing next to an existing thermoelectric power plant. The final design provides a first step towards the refinement and development of a system capable of efficiently returning an amount of biomass large enough to replace non-renewable resources. Finally, an innovative methodology applied to the dryer is discussed that could recover water evaporated from the biomass and utilize it for agricultural purposes or within the power plant thermodynamic cycle.
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Pizzimenti, Francesca, Stefano Lauria, Fabio Giulii Capponi, Luca Buono, Francesco Palone, Lorenzo Papi, Roberto Spezie, and Pierluigi Vacante. "Design of a Reduced Scale Prototype for a SiC-based HVDC Hybrid Circuit Breaker for the New Italian HVDC Network." In 2023 IEEE International Conference on Environment and Electrical Engineering and 2023 IEEE Industrial and Commercial Power Systems Europe (EEEIC / I&CPS Europe). IEEE, 2023. http://dx.doi.org/10.1109/eeeic/icpseurope57605.2023.10194794.
Повний текст джерела
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Lie, Halvor, Henning Braaten, Jamison Szwalek, Massimiliano Russo, and Rolf Baarholm. "Drilling Riser VIV Tests With Prototype Reynolds Numbers." In ASME 2013 32nd International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2013. http://dx.doi.org/10.1115/omae2013-11643.
Повний текст джерелаАнотація:
For deep-water riser systems, Vortex Induced Vibrations (VIV) may cause significant fatigue damage. It appears that the knowledge gap of this phenomenon is considerable and this has caused a high level of research activity over the last decades. Small scale model tests are often used to investigate VIV behaviour. However, one substantial uncertainty in applying such results is scaling effects, i.e. differences in VIV response in full scale flow and small scale flow. To (partly) overcome this obstacle, a new innovative VIV test rig was designed and built at MARINTEK to test a rigid full scale riser model. The rigid riser model is mounted vertically and can either be elastically mounted or be given a forced motion. In the present version, the cylinder can only move in the cross-flow (CF) direction and is restricted in the in-line (IL) direction. The paper reports results from a drilling riser VIV experiment where the new rest rig has been used. The overall objective of the work is to study possible VIV suppression to improve operability of retrievable riser systems with auxiliary lines by adding riser fins. These fins are normally used as devices for protection of the auxiliary lines. The test program has recently been completed and analysis is an on-going activity. However, some results can be reported at this stage and more results are planned to be published. A bare riser model was used in a Reynolds number (Rn) scaling effect study. The riser model was elastically mounted and towed over a reduced velocity range around 4 – 10 in two different Rn ranges, 75 000 – 192 000 (subcritical regime) and 347 000 – 553 000 (critical regime). The difference in the displacement amplitude to diameter ratio, A/D, is found to be significant. The elastically mounted riser was also towed with various drilling riser configurations in order to study VIV/galloping responses. One configuration included a slick joint riser model with 6 kill & choke lines; another has added riser fins too. The riser model is based on a specific drilling riser and the kill and choke lines have various diameters and have a non-symmetrical layout. The various riser configurations have also been used in forced motion tests where the towed model has been given a sinusoidal CF motion. Forces have been measured. Determination of the force coefficients is still in progress and is planned to be reported later. Scaling effects appear to be a significant uncertainty and further research on the subject is recommended. The slick joint drilling riser configuration generally increased the displacements compared to displacements of the bare riser model. The drilling riser configuration with protection fins, kill and choke lines generally reduced the displacements compared to displacements of the bare riser model. For both riser systems, tests showed that the response is sensitive to the heading of the current.
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Gu, Jian, Antonio Carlos Fernandes, and Joel Sena Sales. "New Insight on the Effects of Reynolds Number in Vortex Induced Vibration." In ASME 2018 37th International Conference on Ocean, Offshore and Arctic Engineering. American Society of Mechanical Engineers, 2018. http://dx.doi.org/10.1115/omae2018-77699.
Повний текст джерелаАнотація:
So far, the influence of Reynolds number is not sufficiently investigated and it is often implicitly involved in the response plot versus reduced velocity. In the present article, a new dimensionless parameter α (named as “inertial-viscosity ratio”) is introduced for coordinating reduced velocity and Reynolds number. It is shown that individual Reynolds number effects can be explicitly clarified on different branches, through the coordination of α. Besides, this parameter is preliminarily shown to be capable of coordinating two systems with different structural scale, which is believed to potentially reduce the uncertainty caused by large gaps in Reynolds number between reduced model tests and prototype tests.
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Neto, A. R., S. P. Villarreal, and L. Landau. "Ecological Prototype Vessel on Reduced Scale using The Arduino Platform to Remove Floating Solid Wastes that Pollute The Surface of the Fundão Island Canal." In OTC Brasil. Offshore Technology Conference, 2015. http://dx.doi.org/10.4043/26124-ms.
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Diego-Marin, Antonio, Carlos Melendez-Cervantes, Angel Alberto Mendez Aranda, and Armando Giles-Alarcon. "Improvement of the Performance of a Utility Oil Fired Boiler by Modifying the Design of Burners and Atomizers." In ASME 2009 Power Conference. ASMEDC, 2009. http://dx.doi.org/10.1115/power2009-81139.
Повний текст джерелаАнотація:
Reduction of both atomizing steam and particulate emissions were investigated in a 350 MWe utility boiler. A residual fuel oil was dispersed as a fine mist into the furnace with sixteen atomizers of internal turbulent chamber type. The existing atomizers were replaced by Y-jet type atomizers. To do this, full scale prototypes were designed and tested in a cold model rig using mineral oil as the fuel and compressed air as the atomizing medium. The oil droplet size distribution was measured from a single port of each prototype by using a Malvern particle sizer. The prototype to be tested in the power station was selected based on the smallest oil droplets produced along with lower compressed air consumption. In the power station, the burners were modified to install the new design of Y-jet atomizers. Field tests were conducted at 50, 75 and 100% load. Atomizing steam was measured, as well as particulate emissions and the furnace exist flue gas temperature. With the Y-jet atomizers, the atomizing steam was reduced 55% with respect to the original atomizers; the unburned carbon particles were reduced by a maximum of 50%, the furnace exit gas temperature was similar between the two type of atomizers and no side effects were observed in the boiler.
Звіти організацій з теми "Reduced scale prototype"
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Robinson, W. Full-scale evaluation of multi-axial geogrids in road applications. Engineer Research and Development Center (U.S.), March 2022. http://dx.doi.org/10.21079/11681/43549.
Повний текст джерелаАнотація:
The U.S. Army Engineer Research and Development Center (ERDC) constructed a full-scale unsurfaced test section to evaluate the performance of two prototype geogrids, referred to as NX950 and NX750, in road applications. The test section consisted of a 10-in.-thick crushed aggregate surface layer placed over a very weak 2 California Bearing Ratio (CBR) clay subgrade. Simulated truck traffic was applied using one of ERDC’s specially designed load carts outfitted with a single-axle dual wheel truck gear. Rutting performance and instrumentation response data were monitored at multiple traffic intervals. It was found that the prototype geogrids improved rutting performance when compared to the unstabilized test item, and that the test item containing NX950 had the best rutting performance. Further, instrumentation response data indicated that the geogrids reduced measured pressure and deflection near the surface of the subgrade layer. Pressure response data in the aggregate layer suggested that the geogrids redistributed applied pressure higher in the aggregate layer, effectively changing the measured stress profile with an increase in pavement depth.
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Rahman, Mohammad, Ahmed Ibrahim, and Riyadh Hindi. Bridge Decks: Mitigation of Cracking and Increased Durability—Phase III. Illinois Center for Transportation, December 2020. http://dx.doi.org/10.36501/0197-9191/20-022.
Повний текст джерелаАнотація:
Early-age cracking in concrete decks significantly reduces the service life of bridges. This report discusses the application of various concrete mixtures that include potential early mitigation ingredients. Large-scale (7 ft × 10 ft) experimental bridge prototypes with similar restraint conditions found in actual bridges were poured with different concrete mixtures to investigate mitigation techniques. Portland cement (control), expansive Type K cement, internally cured lightweight aggregate (LWA), shrinkage-reducing admixture (SRA), and gypsum mineral were investigated as mitigating ingredients. Seven concrete mixtures were prepared by using individual ingredients as well as a combination of different ingredients. The idea behind combining different mitigating techniques was to accumulate the combined benefit from individual mitigating materials. The combined Type K cement and LWA mixture showed higher concrete expansion compared with mixtures containing Portland cement, Type K cement, LWA, and SRA in the large-scale experimental deck. Extra water provided by LWA significantly enhanced the performance of Type K cement’s initial expansion as well as caused larger total shrinkage over the drying period. A combination of Type K cement and gypsum mineral showed insignificantly higher expansion compared with the individual Type K mixture. Overall, the experimental deck containing SRA showed the least total shrinkage compared with other mixtures. Finite-element modeling was performed to evaluate and predict concrete stress-strain behavior due to shrinkage in typical bridges. A parametric study using finite-element analysis was conducted by altering the structure of the experimental deck. More restraint from internal reinforcement, less girder spacing, larger girder flange width, and more restrictive support conditions increased the concrete tensile stress and led to potential cracking in the concrete deck.
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Galili, Naftali, Roger P. Rohrbach, Itzhak Shmulevich, Yoram Fuchs, and Giora Zauberman. Non-Destructive Quality Sensing of High-Value Agricultural Commodities Through Response Analysis. United States Department of Agriculture, October 1994. http://dx.doi.org/10.32747/1994.7570549.bard.
Повний текст джерелаАнотація:
The objectives of this project were to develop nondestructive methods for detection of internal properties and firmness of fruits and vegetables. One method was based on a soft piezoelectric film transducer developed in the Technion, for analysis of fruit response to low-energy excitation. The second method was a dot-matrix piezoelectric transducer of North Carolina State University, developed for contact-pressure analysis of fruit during impact. Two research teams, one in Israel and the other in North Carolina, coordinated their research effort according to the specific objectives of the project, to develop and apply the two complementary methods for quality control of agricultural commodities. In Israel: An improved firmness testing system was developed and tested with tropical fruits. The new system included an instrumented fruit-bed of three flexible piezoelectric sensors and miniature electromagnetic hammers, which served as fruit support and low-energy excitation device, respectively. Resonant frequencies were detected for determination of firmness index. Two new acoustic parameters were developed for evaluation of fruit firmness and maturity: a dumping-ratio and a centeroid of the frequency response. Experiments were performed with avocado and mango fruits. The internal damping ratio, which may indicate fruit ripeness, increased monotonically with time, while resonant frequencies and firmness indices decreased with time. Fruit samples were tested daily by destructive penetration test. A fairy high correlation was found in tropical fruits between the penetration force and the new acoustic parameters; a lower correlation was found between this parameter and the conventional firmness index. Improved table-top firmness testing units, Firmalon, with data-logging system and on-line data analysis capacity have been built. The new device was used for the full-scale experiments in the next two years, ahead of the original program and BARD timetable. Close cooperation was initiated with local industry for development of both off-line and on-line sorting and quality control of more agricultural commodities. Firmalon units were produced and operated in major packaging houses in Israel, Belgium and Washington State, on mango and avocado, apples, pears, tomatoes, melons and some other fruits, to gain field experience with the new method. The accumulated experimental data from all these activities is still analyzed, to improve firmness sorting criteria and shelf-life predicting curves for the different fruits. The test program in commercial CA storage facilities in Washington State included seven apple varieties: Fuji, Braeburn, Gala, Granny Smith, Jonagold, Red Delicious, Golden Delicious, and D'Anjou pear variety. FI master-curves could be developed for the Braeburn, Gala, Granny Smith and Jonagold apples. These fruits showed a steady ripening process during the test period. Yet, more work should be conducted to reduce scattering of the data and to determine the confidence limits of the method. Nearly constant FI in Red Delicious and the fluctuations of FI in the Fuji apples should be re-examined. Three sets of experiment were performed with Flandria tomatoes. Despite the complex structure of the tomatoes, the acoustic method could be used for firmness evaluation and to follow the ripening evolution with time. Close agreement was achieved between the auction expert evaluation and that of the nondestructive acoustic test, where firmness index of 4.0 and more indicated grade-A tomatoes. More work is performed to refine the sorting algorithm and to develop a general ripening scale for automatic grading of tomatoes for the fresh fruit market. Galia melons were tested in Israel, in simulated export conditions. It was concluded that the Firmalon is capable of detecting the ripening of melons nondestructively, and sorted out the defective fruits from the export shipment. The cooperation with local industry resulted in development of automatic on-line prototype of the acoustic sensor, that may be incorporated with the export quality control system for melons. More interesting is the development of the remote firmness sensing method for sealed CA cool-rooms, where most of the full-year fruit yield in stored for off-season consumption. Hundreds of ripening monitor systems have been installed in major fruit storage facilities, and being evaluated now by the consumers. If successful, the new method may cause a major change in long-term fruit storage technology. More uses of the acoustic test method have been considered, for monitoring fruit maturity and harvest time, testing fruit samples or each individual fruit when entering the storage facilities, packaging house and auction, and in the supermarket. This approach may result in a full line of equipment for nondestructive quality control of fruits and vegetables, from the orchard or the greenhouse, through the entire sorting, grading and storage process, up to the consumer table. The developed technology offers a tool to determine the maturity of the fruits nondestructively by monitoring their acoustic response to mechanical impulse on the tree. A special device was built and preliminary tested in mango fruit. More development is needed to develop a portable, hand operated sensing method for this purpose. In North Carolina: Analysis method based on an Auto-Regressive (AR) model was developed for detecting the first resonance of fruit from their response to mechanical impulse. The algorithm included a routine that detects the first resonant frequency from as many sensors as possible. Experiments on Red Delicious apples were performed and their firmness was determined. The AR method allowed the detection of the first resonance. The method could be fast enough to be utilized in a real time sorting machine. Yet, further study is needed to look for improvement of the search algorithm of the methods. An impact contact-pressure measurement system and Neural Network (NN) identification method were developed to investigate the relationships between surface pressure distributions on selected fruits and their respective internal textural qualities. A piezoelectric dot-matrix pressure transducer was developed for the purpose of acquiring time-sampled pressure profiles during impact. The acquired data was transferred into a personal computer and accurate visualization of animated data were presented. Preliminary test with 10 apples has been performed. Measurement were made by the contact-pressure transducer in two different positions. Complementary measurements were made on the same apples by using the Firmalon and Magness Taylor (MT) testers. Three-layer neural network was designed. 2/3 of the contact-pressure data were used as training input data and corresponding MT data as training target data. The remaining data were used as NN checking data. Six samples randomly chosen from the ten measured samples and their corresponding Firmalon values were used as the NN training and target data, respectively. The remaining four samples' data were input to the NN. The NN results consistent with the Firmness Tester values. So, if more training data would be obtained, the output should be more accurate. In addition, the Firmness Tester values do not consistent with MT firmness tester values. The NN method developed in this study appears to be a useful tool to emulate the MT Firmness test results without destroying the apple samples. To get more accurate estimation of MT firmness a much larger training data set is required. When the larger sensitive area of the pressure sensor being developed in this project becomes available, the entire contact 'shape' will provide additional information and the neural network results would be more accurate. It has been shown that the impact information can be utilized in the determination of internal quality factors of fruit. Until now,