Consulta: subjectFacets:"Numerical simulation"
Registros recuperados: 12
Data/hora: 03/06/2024 07:47:46

INCREASED ENERGY COGENERATION IN THE SUGAR-ENERGY SECTOR WITH THE USE OF SUGARCANE STRAW, ELECTRIFICATION OF DRIVES, AND HIGH-DRAINAGE ROLLERS IN THE EXTRACTION
Provedor de dados: Engenharia Agrícola
Autores: Santos,Paulo S. B. dos; Ramos,Ricardo A. V.
ABSTRACT The sugar-energy sector stands out in the production of electrical energy in the Brazilian energy matrix. The updating of Law 9,427 allowed increasing the limit of power injected in the transmission or distribution systems of existing projects from 30 to 50 MW, encouraging studies of expansion and/or implementation of new cogeneration projects. This study analyzed technologies to enhance energy cogeneration in a plant that sells about 27 MW of surplus power. For this, were studied the use of straw, electrification of drives by steam turbines, and high-drainage rollers (lotus mill roller), which allows reducing bagasse moisture, increasing its lower calorific value (LCV) and, consequently, electrical energy generation. Mass and energy balances in...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Bioelectricity; Biomass; Combustion; Calorific value; Numerical simulation.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162020000200249

SIMULATION OF VENTILATION SYSTEMS IN A PROTECTED ENVIRONMENT USING COMPUTATIONAL FLUID DYNAMICS
Provedor de dados: Engenharia Agrícola
Autores: Silva,Roberto C. da; Cordeiro Júnior,José J. F.; Pandorfi,Héliton; Vigoderis,Ricardo B.; Guiselini,Cristiane.
ABSTRACT Computational simulations of mass and energy flow help in implementing alternative cooling systems in protected environments. The aim of this study was to model and simulate the interaction between external and internal environments of a protected environment by means of computational fluid dynamics (CFD) techniques and validate micrometeorological variables for subsequent comparison between natural and indirect ventilation by ground heat exchangers. At the first phase, the micrometeorological variables global solar radiation (Qg), air temperature (Tair), and air relative humidity (RH) were monitored. The second phase consisted of the numerical modeling of finite volumes, with validation through recorded data, as well as simulation and comparison...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Numerical simulation; Micrometeorology; Protected cultivation; Finite elements.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0100-69162017000300414

Linking wind and interannual upwelling variability in a regional model of the southern Benguela - art. no. 2188
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Blanke, Bruno; Roy, Claude; Penven, Pierrick; Speich, Sabrina; Mcwilliams, James; Nelson, Greville.
We quantify the wind contribution to the development of interannual sea surface temperature (SST) anomalies along the shelf of southern Africa. We compare numerical simulations that differ only in the amount of variability kept in the ERS1/2-derived surface wind forcing. Surprisingly, most of the cold and warm episodes over the Agulhas Bank are strictly related to local fluctuations of the forcing, whereas the shelf of the west coast extending 400 km north of Cape Columbine is equally sensitive to open-sea wind fluctuations. We diagnose the respective role of mesoscale eddy activity and of low frequency and intra-monthly wind fluctuations in generating interannual SST variability. The fair degree of correlation obtained at a few locations between the model...
Tipo: Text
Palavras-chave: Numerical simulation; Wind  fluctuation; Sea surface temperature; Upwelling.
Ano: 2002
URL: https://archimer.ifremer.fr/doc/2002/publication-770.pdf

Mathematical model and numerical simulations of the migration and growth of Biscay Bay anchovy early larval stages
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Boussouar, Ahmed; Le Bihan, Soizick; Arino, Ovide; Prouzet, Patrick.
The paper presents a mathematical model of the early larval stage, from spawn to the resorption of the yolk-sac, of the anchovy, Engraulis encrasicolus, of the Bay of Biscay. The model describes the temperature-dependent growth and drift of passive larvae by the currents and vertical turbulence. A numerical code has been built and numerous simulations, fed by both biological (egg surveys by AZTI-San Sebastian, Spain, and IFREMER, France) and physical (circulation model by IFREMER-Brest, France) data, were undertaken. Their main features are presented and discussed here, and some conclusions on the possible utilization of the results in improving estimates of anchovy stocks by the daily egg production method are drawn.
Tipo: Text
Palavras-chave: Passive stage; Numerical simulation; Migration; Growth; Anchovy; Stade passif; Simulation numérique; Migration; Croissance; Anchois.
Ano: 2001
URL: http://archimer.ifremer.fr/doc/2001/publication-518.pdf

A Lagrangian numerical investigation of the origins and fates of the salinity maximum water in the Atlantic
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Blanke, Bruno; Arhan, Michel; Lazar, A; Prevost, Gwenaelle.
The origins and fates of the Atlantic salinity maximum water (SMW), formed through excess evaporation in the tropics and subtropics of both hemispheres, are studied using monthly mean outputs of a numerical simulation of the world ocean climatological circulation. After defining formation domains from the surface salinity field and the vertical stratification, a Lagrangian technique is used to estimate the formation rates and main pathways in each hemisphere and the role of this water in the framework of the warm water return flow of the meridional overturning cell. Formation rates around 9 and 11 Sv are found in the Southern and Northern Hemispheres, respectively. While the export of the southern SMW from its formation area is realized by the western...
Tipo: Text
Palavras-chave: Atlantic ocean; Lagrangian method; Numerical simulation; Salinity; Sea water.
Ano: 2002
URL: https://archimer.ifremer.fr/doc/2002/publication-769.pdf

Development of a model for flexural rigidity of fishing net with a spring mass approach and its inverse identification by metaheuristic parametric optimization.
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Vincent, Benoit; Di Cesare, Noëlie; Simon, Julien.
The assessment of mesh resistance to opening is a key factor when coming to fishing gear design to study or optimize the fishing selectivity process. Different authors proposed methodologies to achieve twine flexural rigidity identification and mesh opening angle at rest. Their experimental protocols could rely on complex installations and instrumentation, and identification needs dedicated models or software with possible important set up time. Sometimes, different flexural rigidity and rest angle values for a given netting type were proposed depending on identification or experimental conditions, leading to difficulties to choose a value for implementation in netting structures simulation software. The new methodology proposed in this article is based on...
Tipo: Text
Palavras-chave: Fishing net mechanics; Twine flexural rigidity; Numerical simulation; Selectivity; Fishing.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00613/72541/71615.pdf

Numerical simulation of a cod end net - part 1: Equilibrium in a uniform flow
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Le Dret, H; Lewandowski, R; Priour, Daniel; Chagneau, F.
In this paper, a cod-end fish net is modelled by a discrete finite network. The nonlinear elastic energy for such a structure is defined and studied. Numerical simulations of the equilibrium state are performed by minimizing the total energy. The minimization algorithm uses a general nonlinear conjugate gradient procedure.
Tipo: Text
Palavras-chave: Numerical simulation; Nonlinear conjugate gradient; Elastic networks.
Ano: 2004
URL: http://archimer.ifremer.fr/doc/2004/publication-694.pdf

The merging of Kelvin–Helmholtz vortices into large coherent flow structures in a high Reynolds number flow past a wall-mounted square cylinder
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Mercier, Philippe; Ikhennicheu, Maria; Guillou, Sylvain; Germain, Gregory; Poizot, Emmanuel; Grondeau, Mikaël; Thiébot, Jérôme; Druault, Philippe.
Flows at tidal-stream energy sites are characterised by high turbulence intensities and by the occurrence of highly energetic large and coherent flow structures. The interaction of the flow with seabed roughness is suspected to play a major role in the generation of such coherent flow structures. The problem is introduced with canonical wall-mounted square obstacles representing abrupt changes of bathymetry, with high Reynolds number flow (Re = 250000). Two methods are used: a numerical model, based on the LBM (Lattice Boltzmann Method) combined with LES (Large Eddy Simulation) and an experimental set-up in a circulating tank. The numerical model is validated by comparison with experimental data. In the case of a wall-mounted square cylinder, large-scale...
Tipo: Text
Palavras-chave: Turbulence; Coherent flow structure; Numerical simulation; Lattice Boltzmann Method; Large Eddy Simulation; Wall-mounted obstacles.
Ano: 2020
URL: https://archimer.ifremer.fr/doc/00617/72940/72147.pdf

An Updated Geophysical Model for AMSR-E and SSMIS Brightness Temperature Simulations over Oceans
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Zabolotskikh, Elizaveta; Mitnik, Leonid; Chapron, Bertrand.
In this study, we considered the geophysical model for microwave brightness temperature (BT) simulation for the Atmosphere-Ocean System under non-precipitating conditions. The model is presented as a combination of atmospheric absorption and ocean emission models. We validated this model for two satellite instruments-for Advanced Microwave Sounding Radiometer-Earth Observing System (AMSR-E) onboard Aqua satellite and for Special Sensor Microwave Imager/Sounder (SSMIS) onboard F16 satellite of Defense Meteorological Satellite Program (DMSP) series. We compared simulated BT values with satellite BT measurements for different combinations of various water vapor and oxygen absorption models and wind induced ocean emission models. A dataset of clear sky...
Tipo: Text
Palavras-chave: Calibration; Geophysical model; Numerical simulation; SSMIS; AMSR-E; Satellite passive microwave.
Ano: 2014
URL: https://archimer.ifremer.fr/doc/00190/30101/28628.pdf

Numerical and experimental characterisation of interactions between two marine current turbines
Provedor de dados: Institutional Archive of Ifreme (ArchiMer)
Autores: Mycek, Paul; Gaurier, Benoit; Germain, Gregory; Lothode, Corentin; Pinon, Gregory; Rivoalen, Elie.
The implantation and deployment of marine current turbine arrays depend on the understanding of their interactions. Based on a priori suggestions about the layout of marine energy converter arrays, we propose to highlight interactions effects between two horizontal axis marine current turbines, in open water. experimental trials were run in IFREMER’s wave and current flume tank in Boulogne-sur-Mer (France), on marine current turbine models. Our study focuses on setups were the second turbine is axially aligned, at different distances, in the wake of the first one. Interaction effects are pointed out both in terms of performance and wake characterisation by means of a comparison with results on a single turbine. This study shows that the downstream turbine...
Tipo: Text
Palavras-chave: Marine energy; Horizontal axis marine current turbine arrays; Experimental trials; Laser Doppler velocimetry; Numerical simulation; Vortex method.
Ano: 2013
URL: http://archimer.ifremer.fr/doc/00143/25401/23557.pdf

Mathematical modelling of vector-borne diseases and insecticide resistance evolution
Provedor de dados: Journal of Venomous Animals and Toxins Including Tropical Diseases
Autores: Kuniyoshi,Maria Laura Gabriel; Santos,Fernando Luiz Pio dos.
Abstract  Background: Vector-borne diseases are important public health issues and, consequently, in silico models that simulate them can be useful. The susceptible-infected-recovered (SIR) model simulates the population dynamics of an epidemic and can be easily adapted to vector-borne diseases, whereas the Hardy-Weinberg model simulates allele frequencies and can be used to study insecticide resistance evolution. The aim of the present study is to develop a coupled system that unifies both models, therefore enabling the analysis of the effects of vector population genetics on the population dynamics of an epidemic.  Methods: Our model consists of an ordinary differential equation system. We considered the populations of susceptible, infected and recovered...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Epidemiology; Population genetics; Tropical diseases; Insecticides; Theoretical modelling; Numerical simulation; ODE system.
Ano: 2017
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1678-91992017000100321

Numerical simulation of fecal coliform reduction at a constructed wetland
Provedor de dados: Revista Brasileira de Engenharia Agrícola e Ambiental
Autores: Amendola,Mariângela; Souza,Anderson L. de; Roston,Denis M.
The aim of this research was to use experimental planning to collect data and also to establish a methodology to compare them with theoretical data, where both are associated to the dynamics of reduction in pollutants in a natural treatment system for wastewater. The experimental data were collected and evaluated from two of these systems, built according to Valentim &amp;amp; Amendola (1999) and Collaço (2001), at the Center of Mechanization and Agricultural Automation of the Agricultural Institute of Campinas, located in Jundiaí, SP, Brazil. These systems were rectangular in shape; one with crushed stone and another with chopped tires used as support bed to hold the plants, both with macrophyte species Typha sp. The theoretical data were obtained from a...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Numerical simulation; Pollutant-reduction; Constructed wetland.
Ano: 2003
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1415-43662003000300021