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Exposure and the outbreak of diseases result in significant losses in large scale poultry operation. New ventilation systems are necessary to provide safe and homogenous internal environment at large enterprises, especially under the changeable climatic conditions of global warming. Within the framework of this investigation, computational fluid dynamics (CFD) simulation of a side ventilation system in a poultry house during winter seasons has been conducted. As results, 3D temperature fields, current lines and pressures in a poultry house have been found. It has been determined that fresh air valves arranged at a height of 200 mm from flooring work better than those traditionally arranged at a height of 400 mm. The erection of walls on the inside of a poultry house framework as well as the decrease in the height of flooring improve poultry house aerodynamics. РЕЗЮМЕ Переохолодження і спалах хвороби призводять до значних втрат при великомасштабному виробництві птиці. З метою забезпечення безпечного і однорідного внутрішнього середовища для великих виробництв необхідні нові системи вентиляції, особливо в умовах мінливого клімату глобального потепління. В рамках цього дослідження було проведено моделювання обчислення гідродинаміки (CFD) бокової системи вентиляції в пташнику у зимовий період року. В результаті отримано поля швидкостей, ліній току і тисків у пташнику в 3D постановці. Знайдено, що припливні клапана які розміщуються на висоті 200 мм від перекриття працюють значно ефективніше ніж в традиційній постановці на висоті 400 мм. Монтаж стін із внутрішнього боку каркасу пташника, а також зменшення висоти перекриття покращують аеродинаміку в пташнику. INTRODUCTION The paper of Saraz J.A.O. et al., (2012), was aimed at the development of the modern level of using CFD models in the internal broiler house environment and the investigation of their current limitations. It was based on the assumption that CFD models can provide knowledge about the distribution of velocities, the temperatures of air, gases and solid particles in case of natural ventilation, mechanical ventilation and adiabatic pad-and-fan cooling systems. The results of the paper written by Tong, X. J. et al., (2019) show that an upward airflow displacement ventilation system makes it possible to increase the efficiency of air exchange in cages for 46% -129% as well as to provide more homogenous thermal environment with the heat stress of 9.4% in summer and the cold stress of 68% in winter compared to a tunnel ventilation system. The paper published by Cheng Q.Y. et al., (2018), analyses the influence of the height (0.4 m, 0.55 m, 0.7 m, 0.85 m and 1 m) and the intervals (6 m, 9 m, 12 m, 15 m and 18 m) of deflectors on the velocity and air distribution in cage areas. The investigation shows that deflectors can significantly direct air flow 1 Trokhaniak V.I., Assoc. Prof. Ph.D. Eng.; Rogovskii I.L., Prof. Ph.D. Eng.; Titova L.L., Assoc. Prof. Ph.D. Eng.; Dziubata Z.I., Assist. Lect. PhD; Luzan P.H., Assoc. Prof. Ph.D. Eng.; Popyk P.S., Senior Lect., PhD Eng. Vol. 62, No. 3 / 2020 INMATEH – 156 downwards, increase air velocity in cage and pass-through areas for 0.66 m/s and 0.91 m/s respectively, compared to the lack of deflectors, in case of deflectors being 1 m tall and with the interval of 6 m. Some authors’ results, suggested a new cooling system to be applied in a poultry house with the use of heat-exchangers of a special design (Gorobets V.G. et al., 2018; Gorobets V. et al., 2019). CFD simulation of air flows and heat-and-mass exchange in a poultry building is presented. Here, water from subterranean wells is used as a cooler. There are recommendations provided for choosing the design of ventilation systems in poultry houses. In their follow-up studies Gorobets V.G. et al., (2018), optimize the height of extractor-type fan arrangement. It is shown that it is to the point to arrange ventilation equipment at a height of 1.5 m. Here, the area of dead-air zones and the inequality of air velocity distribution close to poultry decrease. Aimed at the decrease of energy cost and the increase of quality indices of air environment when providing the necessary conditions for poultry management, some authors conducted experimental research and numerical simulation. In the process of investigation, the decrease of energy expenditures for establishing microclimate during broiler management has been obtained. The quality of air environment in poultry houses has been increased. It makes it possible to decrease the disposal of feeding stuffs and the loss of poultry stock and, as a result, increase the economic efficiency of production and product quality. (Trokhaniak V.I. et al., 2019) Bustamante E. et al., (2017), consider the methods of side mechanical ventilation to be more efficient compared to other methods. Their CFD simulation shows a wide range of the values of air flow velocity. According to the indoor air velocity, two main conclusions have been drawn: 1 – there is excess inhomogeneity in the area of animal presence; and 2 – the movement of air is insufficient to contribute to bird thermoregulation. Shurub Yu.V. et al., (2018), Shurub Yu. et al., (2019) presented the description of loading of various ventilator engines and a combined connection diagram. Zajicek M. and Kic P., (2012), Pourvosoghi N. et al., (2018) presented in their paper a CFD solution for various flow configurations and poultry house forms. The effects of cross and longitudinal ventilation are combined with the change of inlet air flow directions as well as various forms of the cross-sectional area obtained with the help of valves. This paper considers the design of a poultry house in such a way that the walls are arranged on the outside of a concrete framework. Such a design makes aerodynamics inside a poultry house worse. There are a lot of dead-air zones. Due to high flooring, warmth during winter season is concentrated above poultry, which results in the increase of energy costs to heat the building. Fig. 1 presents a traditional poultry house design. The walls are arranged on the outside of a concrete framework. The flooring is not lowered. Thus, the paper is aimed at the improvement of a poultry house design, finding the most effective way to arrange fresh air valves and the improvement of the aerodynamic indices of a poultry house environment with the help of CFD. Fig. 1 Extract of traditional poultry house design with fresh air valves of side ventilation MATERIALS AND METHODS According to the set technical task, the engineering calculation of air exchange during winter season was conducted. In order to remove carbon dioxide, moisture vapour and harmful substances, it was necessary to provide air expenditure being about 155 ths m3/h at the outside temperature being -10оС. The geometrical pattern was constructed in actual size. In order to decrease the estimate time inside along the building, symmetry was applied. That is to say, simulation was conducted for half of a poultry house building only. The calculation was conducted at the air expenditure being 30 kg/s. Outside air temperature was taken to be equal to -100С and the parameters of heat emission were introduced. The walls were made of concrete and were insulated by expanded foam being 35 kg/m3 thick: 60/150/60 mm, respectively. The building was coated by polyurethane being 100 mm thick, 45 kg/m3. The floor was Vol. 62, No. 3 / 2020 INMATEH – 157 insulated by expanded polystyrene being 45 kg/m3 thick, 100 mm for the width of 2 m from the wall around the perimeter of the poultry house, 50 mm for the rest of the area. The length of the poultry house was 120 m, the width was equal to 22.36 m (see Fig. 2). Floor-managed poultry in the building was 41 ths in number, poultry weight was equal to 3.3 kg. It was a heat source and corresponded to +41оС. Ventilation valves Wlotpowietrza 857x337 mm 3000-VFG Przepustowocs 2900 m3/h were applied. They were arranged on the side walls being 79 pcs in total (Fig. 5а). The first ten ventilation valves were arranged at a height of 0.2 m from flooring (see Fig. 3b, Fig. 5а). The rest of the valves were arranged at a height of 0.4 m from flooring (see Fig. 3а, 4, 5а (Н5)). One of the design concepts was to install a spoiler at a slope angle being 75о from a vertical line above fresh air valve (see Fig. 4 (А20)). The length of the spoiler was 0.8 m (L9). Munters EM50 1.5 Hp extraction fans were used, 18 pcs. in total. During winter season 6 pcs were specifically arranged (see Fig. 5b). As a rule, they are arranged in the upper row displaced closer to the centre. Such ventilators can undertake the maximum long-term loading up to 56 Pa. Fig. 2 Suggested cross sectional diagram of poultry house structural dimensions а b Fig. 3 Arrangement of valves along longitudinal walls а – small valves, b – tunnel ventilation valves Fig. 4 schematically presents valve angle side view. The ventilation scheme was constructed in such a way that air flow reached the centre of the building in winter season in order to normalize the aerodynamic parameters of a poultry house. Such a method made it possible to reduce the loss of fresh air pressure in the poultry building. Thus, the following structural alterations were made: the width of the building was increased from 21 m, which was typical in a traditional design, to 22.36 m in a new design. Fig. 4 presents the maximum valve opening of 0.1 m (Н16). Numerical simulation was conducted at valve opening being 0.1 m, 0.066 m and 0.049 m, respectively. Fig. 4 Fresh air valves and spoiler angles Vol. 62, No. 3 / 2020 INMATEH – 158 а b Fig. 5 Side (а) and back end (b) walls of a poultry house The number of elements and faces was quite numerous (Table 1). Taking into account great building dimensions, the size of an element and a face was not significantly increased because of the limitations of comp

USING CFD SIMULATION TO INVESTIGATE THE IMPACT OF FRESH AIR VALVES ON POULTRY HOUSE AERODYNAMICS IN CASE OF A SIDE VENTILATION SYSTEM