Consulta: subjectFacets:"CFD"
Registros recuperados: 8
Data/hora: 06/06/2024 05:53:07

Intercomparison of Three Open-Source Numerical Flumes for the Surface Dynamics of Steep Focused Wave Groups
Provedor de dados: 5
Autores: Vyzikas, Thomas; Stagonas, Dimitris; Maisondieu, Christophe; Greaves, Deborah.
NewWave-type focused wave groups are commonly used to simulate the design wave for a given sea state. These extreme wave events are challenging to reproduce numerically by the various Numerical Wave Tanks (NWTs), due to the high steepness of the wave group and the occurring wave-wave interactions. For such complex problems, the validation of NWTs against experimental results is vital for confirming the applicability of the models. Intercomparisons among different solvers are also important for selecting the most appropriate model in terms of balancing between accuracy and computational cost. The present study compares three open-source NWTs in OpenFOAM, SWASH and HOS-NWT, with experimental results for limiting breaking focused wave groups. The comparison...
Tipo: Text
Palavras-chave: Extreme waves; Focused waves; Dispersion; Harmonic analysis; CFD; OpenFOAM; SWASH; HOS.
Ano: 2021
URL: https://archimer.ifremer.fr/doc/00665/77755/79880.pdf

Numerical study of upstream disturbances on the performance of electromagnetic and ultrasonic flowmeters
Provedor de dados: 63
Autores: Palau,Carmen Virginia; Bomfim,Guilherme Vieira do; Azevedo,Benito Moreira de; Peralta,Iban Balbastre.
ABSTRACT Electromagnetic and ultrasonic flowmeters are high precision devices that can measure the water flow in pressurized irrigation networks. In these networks, the inadequate installation distance of flow control valves generates upstream disturbances which will increase measurement errors and reduce the accuracy of the equipment. Therefore, estimating these errors is important to establishing the correct installation distance of the hydraulic accessories and to ensuring the metrological reliability of the flowmeters. This work proposes a numerical study using Computational Fluid Dynamics to evaluate water flow behavior in pipes and estimate measurement errors caused by gate and butterfly valves in installation configurations found at pressurized...
Tipo: Info:eu-repo/semantics/other
Palavras-chave: CFD; Pressurized irrigation; Water flowmeter; Water supply network.
Ano: 2020
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162020000401602

Application of computational fluid dynamics on a study in swine facilities with mechanical ventilation system
Provedor de dados: 63
Autores: Sousa Junior,Vilmar Rodrigues de; Sabino,Luana Araújo; Moura,Daniella Jorge de; Nunhez,José Roberto; Sonoda,Lilia Thays; Silva,Alexandre Oliveira; Prada,Ronald Jaimes; Fontoura,Diener Volpin Ribeiro; Seber,Rogério Torres.
ABSTRACT: Ventilation systems used in swine facilities deserve to be studied because they directly affect productivity in the pig farming sector. Bearing this in mind the uniformity of air distribution and temperature is essential to animal welfare in this breeding environment. Thus, the purpose of this study was to identify whether changes in air entrances and exhaust fan positioning could influence air velocity and temperature distribution. The experimental data were collected in a commercial full-scale sow facility. Validation was carried out by comparing the simulated air temperatures and data measured in the field. These results showed agreement between data with a maximum relative error of approximately 3 %. The real settings showed a gradual...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: CFD; Airflow pattern; Temperature distribution.
Ano: 2018
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0103-90162018000300173

Determinación de los gradientes térmicos nocturnos en un invernadero usando dinámica de fluidos computacional
Provedor de dados: 115
Autores: Espinal-Montes,Verónica; López-Cruz,I. Lorenzo; Rojano-Aguilar,Abraham; Romantchik-Kriuchova,Eugenio; Ramírez-Arias,Armando.
En regiones con climas secos y templados, como los del centro y norte de México, los productores de cultivos en invernadero enfrentan temperaturas nocturnas bajas, que se agudizan en algunas temporadas del año. En un invernadero éstas pueden contrarrestarse con sistemas de calefacción; pero cuando no se tiene el recurso, el ingreso de aire frío se evita con el cierre de ventanas. El objetivo del presente estudio fue desarrollar un modelo basado en Dinámica de Fluidos Computacional (CFD) para evaluar las variaciones de temperatura y flujo de aire nocturno en un invernadero en dos escenarios: ventanas laterales cerradas y abiertas. Los datos usados en las simulaciones fueron recolectados durante el invierno de 2012, en un invernadero tipo sierra con cubierta...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Modelo numérico; Inversión térmica; CFD.
Ano: 2015
URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952015000300001

Redes bayesianas aplicadas a un modelo CFD del entorno de un cultivo en invernadero
Provedor de dados: 115
Autores: de la Torre-Gea,Guillermo; Delfín-Santisteban,Oscar; Torres-Pacheco,Irineo; Soto-Zarazúa,Genaro; Guevara-González,Ramón; Rico-García,Enrique.
Los avances en sistemas y recursos informáticos permiten desarrollar modelos para simular el comportamiento de los fluidos en invernaderos. Sin embargo, la predicción de los gradientes de masa y energía, en los invernaderos con el cultivo y ventilación natural, es difícil por la naturaleza estocástica del viento y las relaciones de dependencia entre la temperatura, CO2 y humedad relativa. Existen técnicas heurísticas, como las Redes Bayesianas, que ayudan a conocer las relaciones entre las variables que no pueden determinarse con herramientas estadísticas. El objetivo del presente estudio fue determinar la temperatura, concentración de CO2 y humedad relativa con respecto a la altura del cultivo, en un invernadero con ventilación natural, mediante Redes...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: CFD; Flujo de aire; Invernadero; Solanum lycopersicum; Ventilación natural.
Ano: 2014
URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952014000300006

Enhancement of the greenhouse air ventilation rate under climate conditions of central Mexico
Provedor de dados: 115
Autores: Romero-Gómez,Pedro; Choi,Christopher Y.; Lopez-Cruz,Irineo L.
Mexican plastic-covered greenhouses use natural ventilation as the main method to control temperature and humidity. However, no studies on the dynamic behavior of airflow and ventilation rates are available. In the present study, air exchange rates were analyzed in a naturally-ventilated greenhouse in Mexico using Computational Fluid Dynamics (CFD). To enhance greenhouse cooling, roof vent areas and screen characteristics were examined undef various scenarios to quantify ventilation rates. The air exchange rates through the tight insect screen (model S) were about 50 % of those achieved with actual and loose insect screen (model SF) at the same outside wind speed. Enlargement of the roof vent size ftom 6 % (current) to 15 % of the greenhouse-floor area...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: CFD; Greenhouse; Natural ventilation; Rates.
Ano: 2010
URL: http://www.scielo.org.mx/scielo.php?script=sci_arttext&pid=S1405-31952010000100001

Numerical Study of Wake Characteristics in a Horizontal-Axis Hydrokinetic Turbine
Provedor de dados: 42
Autores: SILVA,PAULO A.S.F.; OLIVEIRA,TAYGOARA F. DE; BRASIL JUNIOR,ANTONIO C.P.; VAZ,JERSON R.P.
ABSTRACT Over the years most studies on wake characteristics have been devoted to wind turbines, while few works are related to hydrokinetic turbines. Among studies applied to rivers, depth and width are important parameters for a suitable design. In this work, a numerical study of the wake in a horizontal-axis hydrokinetic turbine is performed, where the main objective is an investigation on the wake structure, which can be a constraining factor in rivers. The present paper uses the Reynolds Averaged Navier Stokes (RANS) flow simulation technique, in which the Shear-Stress Transport (SST) turbulent model is considered, in order to simulate a free hydrokinetic runner in a typical river flow. The NREL-PHASE VI wind turbine was used to validate the numerical...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hydrokinetic turbines; Wake characteristics; CFD; Turbulence.
Ano: 2016
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S0001-37652016000602441

A computational fluid dynamics study of hydrogen bubbles in an electrochemical reactor
Provedor de dados: 52
Autores: Cavalcanti,Renata da Silva; Farias Neto,Severino Rodrigues de; Vilar,Eudésio Oliveira.
Most electrochemical reactors present reactions with the growth and departure of gas bubbles which influence on the reactor hydrodynamics and this study is usually complex, representing a vast field for research. The present paper had as objective to study a bi-phase (gas-liquid) system aiming to foresee the influence of departure of hydrogen bubbles generated on effective electrode surface situated on cathodic semi-cell. Nevertheless, it was idealized that the gas was injected into the semi cell, through the effective electrode surface With this hypothesis, it was possible to study, and numerically analyze, the hydrodynamic behavior of the hydrogen bubbles in the interior of the study domain, applying concepts of computational fluid dynamics by using the...
Tipo: Info:eu-repo/semantics/article
Palavras-chave: Hydrogen; Bubble; CFD; Finite volumes; Electrochemical reactor.
Ano: 2005
URL: http://www.scielo.br/scielo.php?script=sci_arttext&pid=S1516-89132005000400027