Numerical study of the gas flow characteristics formed by composite nozzles under oxygen blowing conditions

The paper involves results of numerical modeling in ANSYS of the behavior of gas flows emanating from composite nozzles (consisting of two concentrically placed hollow cylinders with different shares of the peripheral annular part; the same gas (oxygen) is supplied through the inner and outer parts). The study was conducted for different designs of composite nozzles: with 25%, 50%, and 75% peripheral fractions of the nozzle with the same outer nozzle diameter and equal total cross-sectional area. The results were compared with the results of numerical modeling of blowing through a cylindrical nozzle and a Laval nozzle with similar equivalent nozzle diameters. It was found that the peripheral part of the composite-type flow is more responsible for the characteristics of the gas jet formed and its axial velocity parameters. Accordingly, at a peripheral fraction of 25%, a flow is formed with characteristics close to the flow that is formed by a Laval nozzle. When the peripheral fraction is increased to 50% and 75%, a more complex multi-node structure of interacting flows is formed. It is reflected and confirmed by the shadow imaging method and by interaction with a liquid bath using the air–water model.