Numerical studies of the swirling flooded jet flow through the confuser

Abstract

Problem. Swirling currents are often found and used in nature and technology. The variety of tasks encountered in the practice of designing vortex devices often leads to the need to evaluate the parameters of a flooded swirling jet and the need for its numerical calculation. Modern methods of experimental and numerical research require large expenditures of financial resources and time for calculation. Goal. Therefore, for engineering purposes, simplified algorithms of justified and adequate models for calculating flow parameters with minimal computational costs are required, which are the SST turbulence model investigated in the work, adjusted to rotation and curvature. Methodology. The mathematical model includes, in addition to the turbulence model, the Navier-Stokes equations averaged by Reynolds. Results. The influence of the rotation-correction of the SST turbulence model is estimated. Although the swirl number is chosen as the main parameter for comparison, studies have shown that when the main parameters affecting the swirl number change in absolute units, the flow patterns may differ, which requires some attention when using the published study by engineers. This also confirms the need for independent calculations when changing the size of the output nozzle to assess the degree of jet attenuation and velocities in absolute units. Originality. The calculation of the vortex intensity during the passage of the swirling jet through the confuser showed that a larger confuser angle leads to a greater degree of swirling of the flow at the exit from it. Practical value. Using a confuser allows to straighten the flow, and the velocity distribution at the exit from the confuser looks like the velocity distribution of an untwisted flooded jet. The rotation-curvature correction allows us to quickly determine all the main characteristics of the swirl flow with the help of medium power computers.

Keywords

• swirling flows
• confuser
• numerical simulation
• turbulence
• swirl number