Transient CFD analysis of the natural ventilation of three types of greenhouses used for agricultural production in a tropical mountain climate

Microclimatic behavior of a screen house proposed for horticultural production in low-altitude tropical climate conditions

“…Experimental scheme for recording and capturing temperature data inside the screen-house.CFD modelNumerical CFD models allow the development of a technique to solve a set of non-linear partial differential equations through numerical resolution methods by which these equations are discretized to a system of linear equations. The CFD methodology allows calculating the air flow patterns and the thermal distribution patterns generated inside a SH, the transport phenomena via free convection can be described by the following general transport equation for a fluid in steady state: in a dimensional shape (moment, mass and energy), y is the source term.The airflow modeled considered the turbulence through the standard k -ε model, this is a semi-empirical model based on the transport equations that solve k kinetic turbulent energy and the dispersion of this energy per unit volume ε, the k -ε has been the most applied and widely validated model in greenhouse or SH airflow studies showing to be efficient with the use of computational resources and providing realistic solutions(Villagrán et al, 2019). The Boussinesq model was considered to simulate and calculate the variations in air density inside the SH generated by temperature changes.…”

“…The density of the mesh was increased in the regions near the screens, floor, side and roof areas which are the regions where relevant thermal gradients are usually found and which in turn were simulated with the improved wall treatment. The independence of the solutions to the size of the mesh,as well as the quality of the mesh was carried out following the procedure established byHe et al (2017) and successfully implemented byVillagrán et al (2019).…”

Evaluation of airflow pattern and thermal behavior of the arched greenhouses with designed roof ventilation scenarios using CFD simulation

“…Bournet et al [14] performed a computational fluid dynamics simulation to predict the effect of venting arrangements on ventilation and microclimate parameters in pitched roof glasshouse. Villagrán et al [15] investigated the influence of different structures of the roof vent on the climate distribution of multi-span greenhouses to propose the recommended greenhouse applying in the high Andean tropics. Kim et al [16] developed numerical model to evaluate wind pressure coefficients of the various ventilation variables used for greenhouse design of reclaimed coastal land such as roof slope, roof curvature radius and number of spans.…”

Comportamiento microclimático diurno, en temporada seca, de tres estructuras para agricultura protegida en el trópico seco

“…Una de las técnicas de modelado y simulación más importantes y ampliamente aplicadas al estudio aerodinámico y micro climático en estructuras de agricultura protegida ha sido la dinámica de fluidos computacional (CFD) que actualmente es conocida como una técnica robusta y avanzada para el diseño en muchos campos de la ingeniería (Tong, Christopher, & Zhang, 2018;. El uso de CFD ha contribuido a mejorar u optimizar los sistemas de ventilación en invernaderos o casas de malla en países como España (Molina-Aiz, Valera, Peña, Gil, & López, 2009), México (Flores-Velázquez, Mejía-Sáenz, Montero-Camacho, & Rojano, 2011) y Colombia (Villagrán, Gil, Acuña, & Bojacá, 2012;Villagrán, Baeza-Romero, & Bojacá, 2019).…”