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Numerical model of thermal necrosis due a dental drilling process

Fonseca, E.M.M.; Magalhães, K.; Fernandes, M.G.; Barbosa, M.P.; Sousa, G.
Fonte: Instituto Politécnico de Bragança Publicador: Instituto Politécnico de Bragança
Tipo: Conferência ou Objeto de Conferência
ENG
Relevância na Pesquisa
65.82%
The main goal of this paper is to present a numerical model for studying the thermal necrosis due a dental drilling process. The finite element method was used with Ansys program for the transient thermal analysis. Also an experimental process is explained to determine the thermal occurrence in a pork mandible. The in-crease of temperature produced during the drilling is compared using the two different methodologies. According the obtained results, the numerical model could be a technique to induce appropriated results with-out using in-vivo models.

Steel fibre reinforced concrete pipes. Part 2: numerical model to simulate the crushing test; Tubos de concreto reforçado com fibras de aço. Parte 2: modelo numérico para simular o ensaio de compressão diametral

Fuente, A. de le; Figueiredo, A. D. de; Aguado, A.; Molins, C.; Chama Neto, P. J.
Fonte: IBRACON - Instituto Brasileiro do Concreto Publicador: IBRACON - Instituto Brasileiro do Concreto
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
65.91%
This paper is part of an extensive work about the technological development, experimental analysis and numerical modeling of steel fibre reinforced concrete pipes. The first part ("Steel fibre reinforced concrete pipes. Part 1: technological analysis of the mechanical behavior") dealt with the technological development of the experimental campaign, the test procedure and the discussion of the structural behavior obtained for each of the dosages of fibre used. This second part deals with the aspects of numerical modeling. In this respect, a numerical model called MAP, which simulates the behavior of fibre reinforced concrete pipes with medium-low range diameters, is introduced. The bases of the numerical model are also mentioned. Subsequently, the experimental results are contrasted with those produced by the numerical model, obtaining excellent correlations. It was possible to conclude that the numerical model is a useful tool for the design of this type of pipes, which represents an important step forward to establish the structural fibres as reinforcement for concrete pipes. Finally, the design for the optimal amount of fibres for a pipe with a diameter of 400 mm is presented as an illustrating example with strategic interest.

"Experimentos e modelagem numérica com aplicação ao Estuário Tropical do Rio Curimataú, RN" ; Experiments and numerical model with application to the tropical estuary of the Catimataú river, RN

Andutta, Fernando Pinheiro
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 23/06/2006 PT
Relevância na Pesquisa
65.88%
A distribuição e a variabilidade de propriedades termohalinas e a circulação tridimensional do estuário do rio Curimataú foram estudadas com a aplicação do modelo numérico de simulações Delft3D-Flow, validado com dados experimentais medidos durante dois ciclos consecutivos de maré de quadratura e de sizígia. Duas grades numéricas foram aplicadas com o intuito de observar as diferenças entre as simulações nos modos barotrópico e baroclínico. As condições iniciais de simulações tais como: salinidade, velocidade, densidade e coeficientes cinemáticos de viscosidade, difusividade horizontal e vertical foram obtidas mediante resultados de simulações sob condições iniciais homogêneas. A seguir, o modelo numérico foi utilizado em condições mais realistas que foram comparadas aos dados experimentais. As simulações para a estrutura de salinidade, no modo barotrópico na maré de sizígia, apresentaram os melhores resultados, em comparação com os resultados experimentais, confirmado pelo índice de validação Skill igual 0,96; no modo baroclínico as simulações também foram de boa qualidade e o Skill foi muito próximo ao anterior (0,94). As simulações teóricas do campo de velocidade também foram de boa qualidade...

"Determinação de características da circulação marítima forçada por ventos no litoral norte do Estado de São Paulo através de modelagem numérica hidrodinâmica"; Hydroynamics Numerical Model, northern coastal area of São Paulo state, surface winds, Wind driven currentes, seasonal and monthly variations, winds transient effects.

Borovik, Roseana Pellozo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 15/12/2006 PT
Relevância na Pesquisa
55.81%
Uma versão do POM - Princeton Ocean Model foi implementada no litoral norte do Estado de São Paulo, região compreendida entre as longitudes 46o e 44o30'W e latitudes 24o30' e 23o18'S, abrangendo as cidades de Bertioga, São Sebastião, Caraguatatuba e Ubatuba, da linha da costa até aproximadamente a isóbata de 100 m, para estudos da resposta do mar ao vento. Para tanto foram realizados diferentes experimentos numéricos, combinando diferentes períodos e forçantes (de maré, vento e campos médios mensais de temperatura e salinidade). As respostas das simulações foram comparadas entre si, com estudos anteriores e a dados reais de diferentes fontes (marégrafo, correntômetro e altímetro). As simulações reproduziram razoavelmente os dados medidos, demostrando uma boa calibração do modelo. Foi observado o padrão de correntes predominantes para sudoeste, infuenciado pela Alta Subtropical do Atlântico Sul e seus ventos de nordeste, bem como eventuais efeitos de frentes frias com ventos de sudoeste e correntes para nordeste.Também se observou que as frentes frias mais intensas não ocorreram nos meses de inverno para os processamentos do ano de 2005, que apresentou várias situações anômalas, como por exemplo: um mês de Fevereiro com excepcional persistência de ventos do quadrante sul; ventos muito fracos em Março; Junho também com ventos fracos e praticamente ausência de frentes frias; e Setembro e Outubro com incursões muito freqüentes de frentes. Apesar das anomalias dos ventos e correspondentes campos de correntes...

Desenvolvimento de modelo numérico para gerenciamento de recursos hídricos subterrâneos na área do projeto pitoto de Ribeirão Preto; Numerical model for ground water management in the Ribeirão Preto pilot project area

Cavicchia, Marcelo Eduardo
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Dissertação de Mestrado Formato: application/pdf
Publicado em 26/10/2007 PT
Relevância na Pesquisa
55.81%
Este projeto apresenta a construção de um modelo numérico do Sistema Aqüífero Guarani pelo método de elementos finitos para auxiliar o gerenciamento de recursos hídricos subterrâneos na área do projeto piloto de Ribeirão Preto, localizada na região nordeste do Estado de São Paulo. Dados topográficos, hidrológicos e hidrogeológicos da região de interesse foram obtidos principalmente de mapas (impressos e digitais) e poços cadastrados junto a órgãos governamentais, em cooperação com o grupo coordenador do projeto piloto de Ribeirão Preto. Os dados levantados foram armazenados, processados e analisados utilizando ferramenta SIG, seguida da geração de mapas interpolados com características hidrogeológicas. Esses dados foram transferidos para o software de simulação SPA, onde se deu a construção da malha de elementos finitos e a atribuição dos parâmetros e condições de contorno ao modelo. Em seguida, foi feita uma análise de sensibilidade do modelo, e testadas algumas configurações de parâmetros hidrogeológicos e de taxas de recarga. O modelo apresentou bons resultados e desempenho, e, como parte de uma constante evolução, são propostas visitas de campo para verificação de dados para o seguimento desse projeto.; This work presents a numerical model for the Guarani Aquifer System management in the Ribeirão Preto pilot project area...

Circulação e massas de água na plataforma continental leste do Ceará: modelagem numérica e observações; Circulation and water masses in continental shelf of Ceará State: numerical modeling and observations

Dias, Francisco José da Silva
Fonte: Biblioteca Digitais de Teses e Dissertações da USP Publicador: Biblioteca Digitais de Teses e Dissertações da USP
Tipo: Tese de Doutorado Formato: application/pdf
Publicado em 13/12/2011 PT
Relevância na Pesquisa
55.8%
A Plataforma Continental do Estado do Ceará (PCCE) foi dividida em: Plataforma Continental Externa (PCE), Plataforma Continental Média (PCM) e Plataforma Continental Interna (PCI). Os critérios físicos adotados levaram em consideração intrusões mais ou menos intensas de água tropical (AT) transportada pela Corrente Norte do Brasil (CNB) em direção à costa; a intensificação dos gradientes de salinidade superficial; e a mistura entre diferentes massas de água. Durante a estação de chuva, observamos que na região da PCE a massa de Água Tropical (AT) ficou aprisionada em níveis verticais maiores que 60 m, enquanto que na PCI observamos a formação de uma pluma estuarina que ocupou os dois primeiros metros da coluna de água e provocou o rebaixamento do topo da massa de água costeira (AC), chegando a 6 km da linha de costa. A variação espaço-temporal das correntes na frequência submaregráfica mostram que a tensão de cisalhamento do vento (TCV) foi o principal agente na transferência de momentum para as águas da PCCE, gerando uma corrente de deriva polarizada para NW, paralela à direção das isóbatas, em resposta ao empilhamento de água na costa. Este comportamento, associado a espessura da camada de Ekman muito maior que a profundidade local...

The water quality of the Ria de Aveiro lagoon, Portugal: from the observations to the implementation of a numerical model

Lopes, J. F.; Dias, J. M.; Cardoso, A. C.; Silva, C. I. V.
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
ENG
Relevância na Pesquisa
65.87%
Ria de Aveiro is a very important area of the Portuguese coast, which has been under an increasing anthropogenic pressure for several decades and, contributes to the degradation of the lagoon’s water quality. This work presents both a characterisation of the water quality of the Ria de Aveiro lagoon, using physical, chemical and biological experimental data, and an implementation of a numerical model for the water quality of the lagoon. The ultimate goal is to obtain an accurate numerical model able to simulate major water quality features of the lagoon under the influence of different forcing conditions. Data analysis reveals good correlations between the salinity and almost all the water quality variables as well as between the different variables. The maximum biochemical oxygen demand concentration (BOD) depends on the light intensity, the temperature and the river inputs. The main vulnerable areas of the lagoon, from the water quality point of view, seem to be the far end of the main channels, where low dissolved oxygen concentration (DO) and high BOD concentrations are observed. The numerical model of the Ria de Aveiro has reproduced both winter–spring and spring–summer events related to the lagoon water quality as well as its main pattern. Both data and modelling results show that the BOD5 concentrations (where the subscript ‘5’ means that the BOD measurements were conducted for five days...

Numerical modeling of the effect of variation of boundary conditions on vadose zone hydraulic properties

Leão,Tairone Paiva; Gentry,Randall
Fonte: Sociedade Brasileira de Ciência do Solo Publicador: Sociedade Brasileira de Ciência do Solo
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/02/2011 EN
Relevância na Pesquisa
55.76%
An accurate estimation of hydraulic fluxes in the vadose zone is essential for the prediction of water, nutrient and contaminant transport in natural systems. The objective of this study was to simulate the effect of variation of boundary conditions on the estimation of hydraulic properties (i.e. water content, effective unsaturated hydraulic conductivity and hydraulic flux) in a one-dimensional unsaturated flow model domain. Unsaturated one-dimensional vertical water flow was simulated in a pure phase clay loam profile and in clay loam interlayered with silt loam distributed according to the third iteration of the Cantor Bar fractal object Simulations were performed using the numerical model Hydrus 1D. The upper and lower pressure heads were varied around average values of -55 cm for the near-saturation range. This resulted in combinations for the upper and lower constant head boundary conditions, respectively, of -50 and -60 cm, -40 and -70 cm, -30 and -80 cm, -20 and -90 cm, and -10 and -100 cm. For the drier range the average head between the upper and lower boundary conditions was set to -550 cm, resulting in the combinations -500 and -600 cm, -400 and -700 cm, -300 and -800 cm, -200 and -900 cm, and -100 and -1,000 cm, for upper and lower boundary conditions...

A numerical model of transient thermal transport phenomena in a high-temperature solid–gas reacting system for CO₂ capture applications

Yue, Lindsey; Lipiński, Wojciech
Fonte: Elsevier Publicador: Elsevier
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
55.81%
A numerical model coupling transient radiative, convective, and conductive heat transfer, mass transfer, and chemical kinetics of a heterogeneous solid–gas reacting system has been developed and applied to a model reaction: the decomposition of calcium carbonate into calcium oxide and carbon dioxide. The model reaction is one of two reactions involved in calcium oxide looping, a proposed thermochemical process suitable for use with concentrated solar radiation for the capture of carbon dioxide. The analyzed system is a single, porous particle in an idealized, reactor-like environment that is subjected to concentrated solar irradiation. The finite volume and explicit Euler methods are used to solve volume-averaged governing equations numerically. The model predicts the time-dependent temperature distributions as well as local solid and fluid phase composition. For the baseline simulation, complete decomposition of a 2.5 mm radius particle exposed to 1 MW m¯² solar irradiation is reached in 35 s. The model is further used to investigate physical parameters and operating conditions under which solar-driven calcium oxide looping may be employed for carbon capture. Time to complete conversion decreases under conditions favorable for increased rate of heating...

Numerical simulation of steel plated RC columns

Wu, Y.; Griffith, M.; Oehlers, D.
Fonte: Pergamon-Elsevier Science Ltd Publicador: Pergamon-Elsevier Science Ltd
Tipo: Artigo de Revista Científica
Publicado em //2004 EN
Relevância na Pesquisa
55.81%
A numerical model is described in this paper that can analyse a cantilever beam/column member with partial interaction plating under lateral loading. This type of analysis is complicated due to the relative movement, or slip, that occurs at the interface between the concrete and plate elements. The accuracy of the numerical procedure was verified through comparisons with laboratory tests results. The numerical procedure was found to be numerically stable over the full range of response, including post-peak behaviour. The numerical analyses of plated RC columns also show that steel plating can be used to improve a column’s strength, ductility, or both.; http://www.elsevier.com/wps/find/journaldescription.cws_home/359/description#description; Yu-Fei Wu, Michael C. Griffith and Deric J. Oehlers

Restart model for a multi-plug gelled waxy oil pipeline

Davidson, M.; Nguyen, Q.; Ronningsen, H.
Fonte: Elsevier Science BV Publicador: Elsevier Science BV
Tipo: Artigo de Revista Científica
Publicado em //2007 EN
Relevância na Pesquisa
55.74%
A numerical model has been developed to simulate the restart behaviour of pipeline containing gelled waxy oil. The model takes into account the compressible, multi-phase and multi-plug flow characteristics of the gelled oil at start-up. The pipe is initially filled by the gelled oil in the form of plugs separated by pockets of gas. Displacement of the gelled oil is achieved by pumping in another fluid under constant applied pressure. The simulation results obtained show that the initial gas pressure and the location of the gas segment influence the flow of the downstream oil plug, but has little effect on the flow of the upstream oil flow and the clearance time. The length of the gas section has different effects on the oil flow rates and clearance time depending on the initial liquid hold up present in the pipe. The model is robust and insensitive to the specific constitutive model assumed for the gelled oil. It appears to produce a more realistic prediction of the restart flow than other previous models based on restrictive and simplified assumptions.; http://www.elsevier.com/wps/find/journaldescription.cws_home/503345/description#description; Malcolm R. Davidson, Q. Dzuy Nguyen, and Hans Petter Rønningsen; Copyright © 2007 Elsevier B.V. All rights reserved.

SIMULATING REMEDIATION OF TRICHLOROETHYLENE IN FRACTURED BEDROCK BY THERMAL CONDUCTIVE HEATING USING THE NUMERICAL MODEL TMVOC

MCKENZIE, ASHLEY
Fonte: Quens University Publicador: Quens University
Tipo: Tese de Doutorado
EN; EN
Relevância na Pesquisa
65.85%
A thermal conductive heating (TCH) pilot test was conducted at the Naval Air Warfare Center (NAWC) in West Trenton, New Jersey in 2009 in collaboration with TerraTherm, Inc., the Naval Facilities Engineering Services Center and the United States Geological Survey. The NAWC site was historically used as a jet engine testing facility from the mid-1950s to the late 1990s. During this time, the subsurface was contaminated with trichloroethylene (TCE) which was a common solvent used at the facility. The pilot test consisted of 15 heater/extraction wells installed to a depth of 16.8 m in weathered mudstone and operated for 102 days. Rock core samples were taken pre- and post-remediation to measure the initial TCE concentrations and evaluate the effect the TCH pilot test had. The data collected during the pilot test was used to create a two-dimensional (2D) finite difference model using TMVOC. TMVOC is part of the TOUGH 2 family of codes and is a numerical model that is capable of simulating multiphase flow, heat transfer and transport of volatile organic compounds in three-dimensional heterogenous porous media or fractured rock. The 2D model was used as a screening model to investigate TCE removal from the rock matrix when heating for 100 days with a similar heating pattern to what was employed at the NAWC site. The numerical domain incorporated three primary fractures with competent bedrock in between. As the test pilot was conducted in the weathered bedrock zone...

Numerical analysis of waffle slabs in flexure considering the effects of concrete cracking

Recalde,B. R. B.; Gastal,F. P. S. L.; Bessa,V. R. D'A; Schwetz,P. F.
Fonte: IBRACON - Instituto Brasileiro do Concreto Publicador: IBRACON - Instituto Brasileiro do Concreto
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2015 EN
Relevância na Pesquisa
55.87%
Waffle slab structures simulated by computational model are generally analyzed by simplified methods, for both the section geometry (converting into solid slabs or grids) and for the material mechanical properties (linear elastic regime). Results obtained by those studies show large differences when compared with test results, even at low loading levels. This is mainly due to lack of consideration of the eccentricity between the axis of the ribs and the cover, as well as the simplification of the mechanical behavior of concrete tensile strength. The so called more realistic numerical models do consider the effect of the eccentricity between the axis of the cover and ribs. One may also introduce physical nonlinearity of reinforced concrete in these models, obtaining results closer to tests. The objective of this work is to establish a numerical model for the typical section of waffle slabs given the recommendationslisted above. Such model considers the eccentricity between the axis of the ribs and the cover, the physical nonlinearity of concrete in compression and the concrete contribution between cracks (tension stiffening) through a smeared crack model. The finite element program SAP2000 version 16 is used for the non-linear analysis. The area element discretization uses the Shell Layered element along the thickness of layers...

Numerical Model Construction with Closed Observables

Dietrich, Felix; Köster, Gerta; Bungartz, Hans-Joachim
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
55.91%
Performing analysis, optimization and control using simulations of many-particle systems is computationally demanding when no macroscopic model for the dynamics of the variables of interest is available. In case observations on the macroscopic scale can only be produced via legacy simulator code or live experiments, finding a model for these macroscopic variables is challenging. In this paper, we employ time-lagged embedding theory to construct macroscopic numerical models from output data of a black box, such as a simulator or live experiments. Since the state space variables of the constructed, coarse model are dynamically closed and observable by an observation function, we call these variables closed observables. The approach is an online-offline procedure, as model construction from observation data is performed offline and the new model can then be used in an online phase, independent of the original. We illustrate the theoretical findings with numerical models constructed from time series of a two-dimensional ordinary differential equation system, and from the density evolution of a transport-diffusion system. Applicability is demonstrated in a real-world example, where passengers leave a train and the macroscopic model for the density flow onto the platform is constructed with our approach. If only the macroscopic variables are of interest...

Numerical Model For Vibration Damping Resulting From the First Order Phase Transformations

Wang, Linxiang X.; Melnik, Roderick V. N.
Fonte: Universidade Cornell Publicador: Universidade Cornell
Tipo: Artigo de Revista Científica
Publicado em 28/02/2007
Relevância na Pesquisa
55.82%
A numerical model is constructed for modelling macroscale damping effects induced by the first order martensite phase transformations in a shape memory alloy rod. The model is constructed on the basis of the modified Landau-Ginzburg theory that couples nonlinear mechanical and thermal fields. The free energy function for the model is constructed as a double well function at low temperature, such that the external energy can be absorbed during the phase transformation and converted into thermal form. The Chebyshev spectral methods are employed together with backward differentiation for the numerical analysis of the problem. Computational experiments performed for different vibration energies demonstrate the importance of taking into account damping effects induced by phase transformations.; Comment: Keywords: martensite transformation, thermo-mechanical coupling, vibration damping, Ginzburg-Landau theory

Numerical modeling of the ultrasonic cavitation field and experimental evaluation of bubble density

Dubus, Bertrand; Granger, C.; Mosbah, P.; Moussatov, A.; Schmit, H.; Sztor, L.; Campos-Pozuelo, Cleofé
Fonte: Sociedad Española de Acústica Publicador: Sociedad Española de Acústica
Tipo: Comunicación de congreso Formato: 104694 bytes; application/pdf
ENG
Relevância na Pesquisa
55.76%
6 pages.-- PACS nr.: 43.35 Ei.-- Communication presented at: Forum Acusticum Sevilla 2002 (Sevilla, Spain, 16-20 Sep 2002), comprising: 3rd European Congress on Acoustics; XXXIII Spanish Congress on Acoustics (TecniAcústica 2002); European and Japanese Symposium on Acoustics; 3rd Iberian Congress on Acoustics.-- Special issue of the journal Revista de Acústica, Vol. XXXIII, year 2002.; A numerical model of ultrasonic cavitation field is described. It is based on a phenomenological description of a cavitating fluid as a non linear fluid whose characteristics (sound speed, density) depend upon the bubble density. To obtain the constitutive relationship between bubble density and acoustic pressure, a real-time measurement method of the bubble density, relying upon the variation of the electrical resistance of the medium, is proposed. The finite element formulation of the model is derived and implemented in the ATILA code. Computational results on the cavitation field created by a cylindrical concentrator are presented.; This work was supported by CNRS and CSIC (French-Spanish cooperation project #7967) and by the European Union (Feder-Retex II).; Peer reviewed

Simulação da propagação das nove principais componentes de maré na plataforma sudeste Brasileira através de modelo numérico hidrodinámico; Simulation of the nine principal tidal constituents propagation in the southeastern Brazilan shelf through a hydrodinamical numerical model

Harari, Joseph; Camargo, Ricardo de
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; ; Formato: application/pdf
Publicado em 01/12/1994 POR
Relevância na Pesquisa
55.76%
Este trabalho apresenta a simulação das nove principais componentes de maré na plataforma sudeste brasileira, através do processamento de um modelo numérico hidrodinâmico. A área modelada se estende da Ponta do Vigia (SC) a Cabo Frio (RJ), da costa até aproximadamente a isóbata de 100 m. O modelo usado nas simulações é tri-dimensional, linear, barotrópico e de meso escala. Cada componente principal de maré foi processada isoladamente, com o objetivo de determinar suas características na área de interesse, especificamente suas linhas cotidais e as elipses de correntes na superfície. As componentes de maré consideradas foram: Q1, O1, P1, K1, N2, M2, S2, K2 e M3. Os mapas cotidais de amplitude e fase obtidos mostram as áreas de amplificação e de atenuação para as ondas de maré, bem como seus sentidos de propagação. Por outro lado, as elipses de correntes na superfície indicam o comportamento das correntes de maré na área modelada, especialmente em termos dos giros, direções predominantes e intensidades típicas. Com os resultados das simulações, é possível prever as elevações e as correntes de maré, em qualquer local desta área, e para qualquer período de interesse.; This paper presents the simulation of the nine principal tidal constituents in the southeastern Brazilian shelf...

Modelo numérico tri-dimensional linear da plataforma continental do Estado do Maranhão; Linear three-dimensional numerical model of Maranhão State continental shelf

Pereira, José Edson Rodrigues; Harari, Joseph
Fonte: Universidade de São Paulo. Instituto Oceanográfico Publicador: Universidade de São Paulo. Instituto Oceanográfico
Tipo: info:eu-repo/semantics/article; info:eu-repo/semantics/publishedVersion; Formato: application/pdf
Publicado em 01/01/1995 POR
Relevância na Pesquisa
55.8%
Um modelo numérico hidrodinámico tri-dimensional linear, do tipo Heaps, foi implementado para a plataforma continental do Estado do Maranhão, visando a simulação da circulação gerada por efeitos astronômicos e meteorológicos na área. O modelo foi processado para cinco condições, a fim de calcular a circulação na plataforma devida aos seguintes efeitos: componente de maré semi-diurna lunar principal (M2), composição das principais componentes astronômicas de maré na área, condições meteorológicas médias de verão, condições meteorológicas médias de inverno e forçantes de maré em períodos específicos de interesse. Mapas cotidais e elipses de correntes da componente M2 foram obtidos, sendo esta componente preponderante na circulação local. Elevações e correntes sazonais médias são, em geral, muito menores que as astronômicas, permitindo o uso apenas de forçantes de maré em previsões hidrodinámicas. As simulações do modelo foram satisfatórias na plataforma e menos precisas nas baías e áreas internas rasas, onde atrasos de fase significativos são observados, devido a efeitos de menor escala que a adotada pelo modelo.; A linear three-dimensional hydrodynamical numerical model, Heaps type, was implemented to the continental shelf of Maranhão State...

Numerical models of the evolution of accretionary wedges and fold-and-thrust belts using the distinct-element method

Burbidge, D.; Braun, Jean
Fonte: Blackwell Publishing Ltd Publicador: Blackwell Publishing Ltd
Tipo: Artigo de Revista Científica
Relevância na Pesquisa
55.81%
A 2-D numerical model is used to investigate the evolution of accretionary wedges and fold-and-thrust belts. The numerical method is based on the distinct-element method (DEM). Unlike many continuum numerical models, DEM allows localization to occur even

Model for the development of a low cost thermal mass flow meter

García-Arellano,C.; García-Valladares,O.
Fonte: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería Publicador: UAM, Unidad Iztapalapa, División de Ciencias Básicas e Ingeniería
Tipo: Artigo de Revista Científica Formato: text/html
Publicado em 01/04/2012 EN
Relevância na Pesquisa
55.83%
This paper presents the mathematical model for the development of a water mass flow meter. Its operation principle is based on a relation between a constant input power (heat flow) provided to the system and the increase of temperature in the test section. A numerical model of the thermal and fluid dynamic behavior of the thermal mass flow meter is carried out ; the governing equations (continuity, momentum and energy) inside the tube together with the energy equation in the tube wall and insulation are solved iteratively in a segregated manner. The parametric study developed with the numerical model includes the tube diameter, tube length, and the power supply to the system, with the numerical results obtained and taking into account some restrictions on the system, the final design of the system has been obtained and constructed. A test procedure was carried out to show the technical feasibility of this system and an error of mass flow rate of ± 0.55 % was obtained. In relation to the cost, the errors of experimental measurement are acceptable if they are compared with some of the more common available commercial systems with much higher cost.