Computational Fluid Dynamics (Cfd) Application for Ventilation Studies in Broiler Houses

Abstract

ABSTRACT:With the recent increase in the number of acclimatized broiler houses in Brazil, design and adaptation of facilities to withstand the tropical weather conditions enabling the maintenance of ideal conditions without increasing costs have been major challenges. The aim of this study was to evaluate the ventilation system in solid-wall broiler houses using computational fluid dynamics (CFD). The research was carried out in the city of Amparo -SP (Brazil). The facility consisted of a broiler house enclosed by masonry sidewalls with tunnel ventilation equipped with exhaust fans (air outlet) and cooling pads (air inlet). The following variables were collected: wind speed and dry bulb temperature over 27 equidistant points inside the house at bird height (0.30 m above the floor), wind speed in inlet -cooling pad, and static pressure in the outlet (exhaust fans) as a boundary condition. The data were monitored at the most critical time of the day -2 pm during the final rearing stage in summer. The CFD technique allowed visualizing the air flow according to each running condition for exhaust fans, as well as determined the best setting of exhaust fans, avoiding a low air area renewal and turbulence.

Diagnosis and validation by computational fluid dynamics of poultry house with negative pressure ventilation

“…Xue et al (2016) calculated the average NMSE of 0.15 and considered its CFD model to be valid for analyzing the effects of cooling pad installation on airflow distribution in tunnelventilated laying-hen houses. Curi et al (2017b) found NMSE equal to 0.19 for air velocity and validated a CFD model, generated in Ansys CFX 14.0 software, of a broiler house ventilated with negative pressure. Saraz et al (2011) found a maximum NMSE of 0.0035 for air temperature and validated a simulation model to estimate air temperature distribution in poultry house with tunnel ventilation system.…”

“…The validation of the reference model for the variables T air , RH and V air was performed by comparing the simulation results and their correspondents obtained experimentally. A procedure adopted by Saraz et al (2011); Xue et al (2016) and Curi et al (2017b) was used, in which the normalized mean squared error (NMSE) is calculated according to Eq. 3, and NMSE values less than 0.25 are acceptable as good indicators of agreement.…”

“…In order to optimize the control of internal thermal conditions, diagnosis and validation studies, in which results of fluid simulations were compared to measurements collected in the field, have been carried out (Blanes-Vidal et al, 2008;Bustamante et al, 2013;Hernández et al, 2013;Xue et al, 2016;Curi et al, 2017b). Validated computational fluid dynamics (CFD) models can contribute to reducing time and cost with repetitions in experiments and improving poultry house facilities from parametric simulations, besides providing information on the whole internal environment, whereas field measurements are limited (Bustamante et al, 2015).…”

Thermal comfort monitoring in aviaries by a real-time data acquisition system

“…For alternative boundary conditions, convective heat transfer coefficient (h, W m -2 K -1 ) results in higher values for NMSE in both variables; temperature is ~4%, and airflow speed is ~22% (Camargo, 2015; for details in simulation and results). NMSE values below 25% are indicative of a good correlation between simulation and experimental results (Curi et al, 2017). Homogeneous environmental conditions can be obtained with the control of ventilation systems (Calvet et al, 2011;Bustamante et al, 2013), while literature reference values for air speed are 1.5-2.5 m s -1 (Bustamante et al, 2015).…”

“…For mesh details, see Camargo (2015). A CFD validation analysis was performed by NMSE -Normalized Mean Square Error methodology (Curi et al, 2017).…”