Characteristics of flow in the unit «elbow — supply opening»

The existing literature provides formulas for standard air distribution calculations. However, the calculation coefficients are obtained experimentally for the ideal conditions of connecting air terminal devices. distributors to ducts. In practice, the design of the connection depends on the complexity of the ductwork in the building. This may affect the jet flow conditions and the air circulation in the room. The article considers the flow in the unit «elbow — supply opening» of the ventilation system. The aim of the study is to determine the dependence of the geometric and kinematic characteristics of the jet on the distance between the elbow and the supply opening. The problem is solved numerically in a two-dimensional formulation using the Fluent software package. A combination of the standard k-ε model and standard near-wall functions is used for the solution. As a result, the distribution of velocity and pressure at the outlet of the air terminal device is obtained. The dependences of the variation of the axis slope and axial velocity of the jet, as well as the kinematic coefficient of the supply opening on the distance between the elbow and the supply opening are constructed. The significant influence of the distance between the elbow and the supply opening in the unit on the kinematic characteristics of the jet is shown. The obtained dependencies should be taken into account when calculating air distribution. At distances between the elbow and the supply opening of more than 5 gauges, the characteristics of the jet tend to the characteristics of the jet flowing from the end opening.