Geometric representation of turbulent macrostructure in 3D jets

Abstract

In this work, modelling of 3D jets without any fictitious values is discussed. At first, free axissymmetrical jet is analysed. The approach is based on theory of A. Tkachuk, the Professor of Heat Gas Supply and Ventilation department of Kyiv National University of Construction and Architecture. 3D jets contain large-scale vortices (puffs), which can be represented as spheres. In ventilation technics, the same equations are used for wide range of Reynolds number. Thus, the picture visualized al low Reynolds number can be used for ventilation jets, which can be represented as spheres growing and rolling on the jet boundary. X-velocity inside a sphere can be found by the Euler’s equations for rotation. Between the puffs, the velocity is approximated with smoothness conditions of velocity profile. Average velocity can be found by integration. The results good coincide with known velocity profiles such as Schlichting’s. This allows wide implementation for complex jets.