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The heat released by local exhaust ventilation is one of the most common hazards emitted during various industrial processes in industrial buildings. This work solves problems in order to find the numerical solution model that most adequately describes the development of a free convective jet above a flat heat source and a convective jet near the side hood located above the heat source. Various turbulence models and options of wall functions are considered for application in the study of a free convective jet. The data showed that the closest to theoretical results are those obtained when using the standard k-e model together with standard wall functions.

Calculation of air distribution in premises is one of the main stages when designing ventilation and air conditioning systems of a building. The microclimate quality and the efficiency of ventilation and air conditioning systems depend on the accuracy and correctness of the calculations. The purpose of this study is to assess the influence of the distance between the inlet and the 45-degree turn on the jet characteristics. The basic geometric and kinematic characteristics of the jet flowing from the opening located at various distances from the 45-degree turn were obtained. The change in the deflection of the outflow angle and the kinematic coefficient of the inlet opening were obtained.

Suction hoods are used on a wide-spread basis in ventilation equipment in order to capture harmful substances released by process equipment. The efficiency of such devices is dependent not only on the relative position of the source of contamination and that of the suction hood but also on suction uniformity. Where the location of the source and that of the suction hood is misaligned, the need arises to put in place an uneven velocity field in the suction hood. This papers explores the flow of hazardous substances from the “source” to the “sink” located at an angle of 180 degrees relative to each other. Collection efficiency was determined numerically by means of the Fluent software as well as experimentally. A screen was mounted inside to ensure uneven suction. The study yielded flow current lines and constant temperature lines. It also helped to define maximum suction intensity. The findings may be used for designing ventilation systems intended for industrial buildings.

This paper presents the study of characteristics of porous rotating nozzles recommended for use in gas cleaning devices. The influence of geometrical and technological parameters of atomizer on the size of droplets and the trajectory of their motion is investigated theoretically and experimentally. To determine the droplet size when it is detached from the spherical granule of porous rotating atomizers (PRA), the simulation in the Flow3D program was used. A model for calculating the droplets trajectories when spraying a liquid with the help of porous rotating nozzles is compiled. The model is based on a joint solution of equations of droplet motion in a centrifugal field and evaporation of droplets. The relationship between the volume of separating droplets and the size of granules of porous material and the geometry of atomizer is obtained. The regularities of droplet motion in cylindrical devices with porous rotating atomizers are established depending on the droplets sizes and parameters of the cross-flow. The relationship between parameters of droplets’ trajectory and their volume is recommended for calculating the geometry of the spray torch of PRA in gas cleaning devices.

While considering air exchange scheme in rooms with heat dissipations, it is often preferred when jet flows directly into the working area. It is necessary to take into account the influence of irregularities of velocity profiles in jets that are formed at the outflow from nozzle with different geometry. The jet outflow from inlet holes located beyond elbow was numerically studied. The influence of geometrical parameters of inlet hole on the jet characteristics was investigated. The characteristic flow streamlines for several geometries of a horizontal nozzle, the main characteristics of jet outflow were computed. The relationship between the inlet hole location relative to elbow and the outflow jet characteristics were determined. It was revealed that when the inlet hole is located in close proximity to the elbow, the velocity profiles have strong irregularities, and the jet outflows at an angle to the horizon. When the distance between the hole and the elbow increases, the jet strengthens, the transversal component of velocity does not affect the jet, the outflow angle tends to horizontal. The obtained results can be used for calculating the circulation of air masses in ventilated rooms.