Effect of ventilator configuration on the distributed climate of greenhouses: A review of experimental and CFD studies

Bournet, Pierre-Emmanuel; Boulard, Thierry

doi:10.1016/j.compag.2010.08.007

Cited by 167 publications

(113 citation statements)

References 80 publications

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“…Concordando com CARVALHO (2010), a distribuição das variáveis térmicas e aéreas no espaço não é aleatória, uma vez que todas as variáveis estudadas apresentaram grau de dependência espacial forte ou moderado. A avaliação da homogeneidade dos parâmetros climáticos é essencial para assegurar a qualidade do manejo do ambiente térmico e aéreo a fim de minimizar a ocorrência de regiões quentes e com pouca renovação de ar (pontos mortos), melhorando a qualidade e a produção do lote (BOURNET & BOULARD, 2010).…”

Section: Resultsunclassified

Uso da geoestatística na avaliação de variáveis ambientais em galpão de suínos criados em sistema "wean to finish" na fase de terminação

et al. 2014

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RESUMO:O "wean to finish" é um sistema de criação de suínos que ainda é novo no Brasil, e não existem muitos estudos a respeito do ambiente onde estes animais são criados. Assim, o objetivo deste trabalho foi avaliar o ambiente térmico e aéreo por meio da técnica da geoestatística em galpão de suínos criados no sistema "wean to finish", na fase de terminação, nos horários das 09h, 12h e 15h. A variabilidade dos atributos foi baseada na estatística descritiva dos dados de temperatura, umidade relativa, velocidade do ar, concentrações de amônia e dióxido de carbono, obtendo-se: média, mediana, coeficiente de variação, assimetria e curtose, com o teste de normalidade de Kolmogorov-Smirnov, através do programa estatístico Minitab 15. Para a determinação da existência ou não da dependência espacial, utilizou-se do exame de semivariograma, através do programa GS + , e, na elaboração dos mapas de distribuição espacial das variáveis, foi utilizado o programa Surfer. Os atributos de velocidade do ar e as concentrações dos gases NH3 e CO2 apresentaram alto coeficiente de variação devido aos dados serem heterogêneos, pois a instalação apresentava ventilação natural. O uso dos mapas de krigagem permitiu observar a diferença espacial da distribuição das variáveis avaliadas com diferentes números de animais/baia e em diferentes horários. PALAVRAS-CHAVE: ambiência, distribuição espacial, mapas, suínos. USING GEOSTATISTICS TO EVALUATE THE ENVIRONMENT OF "WEAN TO FINISH"SWINE HOUSING ABSTRACT:The "wean to finish" is a new pig production system in Brazil. To date, few research have investigated the environmental conditions of this pig farming system. The aim of this study was to evaluated the thermal environmental conditions and gases concentration using geostatistical techniques of a wean-to-finish barn during finishing phase at 9AM, 12PM e 3PM. The data variability was evaluated by the descriptive analysis, of the temperatures, relative humidity, air velocity, ammonia and carbon dioxide concentration. The results showed the average, median, coefficient of variation, asymmetry and curtosis and the Kolmogorov-Smirnov Test with the software Minitab 15. To determine the spatial dependence, the semivariogram exam was done, with the software GS + . The air velocity and gases concentration showed the highest coefficient of variation. This has happened because of the heterogeneity of the data caused by the natural ventilation. The Krigging maps showed the spacial differences of the pens with different numbers of animals in different hour of the day.

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Section: Resultsunclassified

Uso da geoestatística na avaliação de variáveis ambientais em galpão de suínos criados em sistema "wean to finish" na fase de terminação

et al. 2014

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“…The homogeneity analysis of climatic parameters is intended to ensure amenities in the environment regarding thermal and air factors, i.e., minimizing hot spots and poor air renewal (dead spaces) (BOURNET & BOULARD, 2010). Thus, Under Kolmogorov-Smirnov testing, all variables recorded inside the facility during F phase showed normal distribution.…”

Section: Z(x1) and Z (X1 + H) -Observations Distant In H (M)mentioning

confidence: 99%

Zoning of environmental conditions inside a wean-to-finish pig facility

et al. 2016

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Using geostatistics, this study aimed to analyze environmental conditions for weanto-finish swines at 3 pm, during the most sensitive phases to thermal stress (growth/ finishing and finishing). To this end, dry-bulb temperature, relative humidity, air speed, ammonia and carbon dioxide concentrations were measured at 81 equidistant points within the barn. Descriptive statistics was used to classify attribute variability, generating mean, median, variation coefficient, asymmetry and kurtosis, through the normality of Kolmogorov-Smirnov (KS). For that, it was used Minitab 15 software. Moreover, semivariograms were used to assess spatial dependence using the GS+ software, and through Surfer, spatial distribution maps were designed. Dry-bulb temperature and relative humidity showed a more homogeneous distribution whether compared to the other attributes. Furthermore, critical points were observed within the facility, with temperatures and low humidity, indicating the need for fogging equipment and fans to improve thermal comfort and animal welfare.

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“…Therefore, it is possible with the use of computers to perform millions of calculations to simulate the interaction of liquids and gases with surfaces defined by the boundary conditions. In recent studies the modeling of air flow, CFD has deepened to test their effectiveness in relationships of climatic factors (Bournet and Boulard, 2010 studies on greenhouse structures can help to the identification of design factors that affect greenhouse ventilation under specific climatic conditions (Romero-Gómez et al, 2008;Romero-Gómez et al, 2010). In the last years, many studies have used CFD to investigate the climatic conditions inside greenhouses.…”

Section: Introductionmentioning

confidence: 99%

“…This implies the choice of a computational domain that is large enough to correctly assess the main mechanisms that occur in the system and to avoid interference with artificial Boundaries (Bournet and Boulard, 2010). The CFD modeling process encompasses three stages: preprocessing, solution and post-processing.…”

mentioning

confidence: 99%

“…However, air distribution inner greenhouse has a third-dimensional (3D) pattern, for that, nowadays 3D CFD models are more commonly developed. According to Bournet and Boulard (2010) the calculation process is an iterative procedure that requires the definition of convergence criteria, and the user of the CFD codes must to decide on an appropriate level of convergence, of the solution. Generally, 10 −4 of the value of a variable at all of the nodes is used.…”

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confidence: 99%

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