Ingeniería Agrícola y Biosistemas Volume 11, issue 1, Avanzada - 2019 Electronic ISSN: 2007-4026
Print ISSN: 2007-3925
Versión en español

 

 

Ingeniería Agrícola y Biosistemas
Volume 11, issue 1, Avanzada - 2019
play_arrow

 

Regional management of the environment in a zenith greenhouse with computational fluid dynamics (CFD)

Gestión regional del ambiente en un invernadero cenital con dinámica de fluidos computacional (DFC)

Jorge Flores-Velázquez; Manuel Vega-García

http://dx.doi.org/10.5154/r.inagbi.2018.04.007

Received: 2018-03-20

Accepted: 2018-10-18

Available online: 2019-02-18 / pages -

  • Introduction: The ability to manipulate environmental conditions within a greenhouse allows production control; however, technological constraints still persist in these systems.
    Objective: To model the environment of a zenith greenhouse cultivated with tomato using computational fluid dynamics (CFD), to propose environmental management alternatives and to estimate the energy expenditure and economic cost of using fans.
    Methodology: The energy expenditure (kW∙h-1) and cost (MXN) of using natural and mechanical ventilation in greenhouses were estimated based on climate data from municipalities in San Luis Potosí and the State of Mexico. The analysis inside the greenhouse was carried out with CFD and climatological normals. In addition, the ventilation rate and thermal gradients were estimated to infer a local climatic potential as a function of optimum tomato temperatures. In addition, the ventilation rate and thermal gradients were estimated to infer a local climatic potential as a function of optimum tomato temperatures.
    Results: It was observed that in regions with mild summers, the use of mechanical ventilation combined with natural ventilation is a viable alternative by reducing temperature and energy costs. The 3D simulations carried out made it possible to have a detailed view of the spatial distribution of temperature and airflow inside the greenhouse. Study limitations: The model only considers wind speed and temperature. To include other variables, it must be calibrated.
    Originality: Ventilation rates (n = 35) and thermal gradients (3 K) were estimated using CFD to infer a regional climatic potential as a function of optimum tomato temperatures. Conclusions: Combined ventilation reduces problems due to high temperatures in hours of maximum radiation, with no significant impact on production costs.

Evaluation of a hypothetical suppression scenario of the spate irrigation system in Coeneo-Huaniqueo, Michoacán, Mexico

Evaluación de un escenario hipotético de supresión del sistema de entarquinamiento en Coeneo-Huaniqueo, Michoacán, México

Elí Gaiska Salomón-Guzmán; Laura A. Ibáñez-Castillo; Jacinta Palerm-Viqueira

http://dx.doi.org/10.5154/r.inagbi.2018.03.003

Received: 2018-03-06

Accepted: 2018-11-07

Available online: 2019-02-18 / pages -

  • Introduction: There is a traditional irrigation system in Mexico called entarquinamiento (spate irrigation), which falls into the flood irrigation category, also known as cajas de agua (literally water boxes). Certain effects generated by traditional irrigation systems are intentional and others not entirely.
    Objective: To demonstrate that spate irrigation systems generate unintended effects such as flood control, in a 100-year return period, in the presence of maximum floods.
    Methodology: A hydrological analysis was carried out for two scenarios: 1) current situation (water boxes operating) and 2) hypothetical situation (boxes for this purpose are suppressed or disused). Within the hydrological model, with the HEC-HMS program, the methodologies of the Soil Conservation Service (SCS) of the United States (runoff curve number and unit hydrograph) and a design storm of 167.8 mm were considered. Flood routing in channels was performed using the Muskingum method.
    Results: With the current situation, the flow rate generated at the box system outlet was 0 m3 ·s-1, which is the product of the partial storage of the runoff, while with the hypothetical situation, the maximum flow rate becomes 535.5 m3 .s-1.
    Study limitations: The efficiency of the water box system as an irrigation technique was not evaluated. Originality: There are few hydrological studies that demonstrate quantitative benefits of traditional irrigation techniques.
    Conclusions: The operating water box system functions as a reservoir. If the boxes were removed, a runoff would be generated that would flood agricultural and urban areas.o que inundaría zonas agrícolas y urbanas.

Indexings:


Conacyt

Latindex

Redib

Oaji