Вентиляція та теплогазопостачання
Постійний URI для цього зібранняhttps://repositary.knuba.edu.ua/handle/987654321/1443
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Документ The Macrostructure Analysis of the Turbulent Mixing Boundary Layer Between Flows with the Same or Opposite Direction(Vilnius Gediminas Technical University, 2014) Mileikovskyi, ViktorThe approach to calculate large-scale vortexes boundary layer using approach of Professor A. Tkachuk is offered. It based on geometrical analysis of idealized macrostructure shown as a growing or constant radius vortex sheet. The small vortices in flows with a large-scale macrostructure plays secondary roles because they have incommensurably less energy than big vortices. They can be eliminated from consideration. We specify the velocity and temperature profile that differs from the jet boundary layer profile and better coincides with experiment. We find a growth law for a free boundary layer and length of currents cores. This approach help us to solve the actual task for energy efficient heating systems. We found the heat exchange coefficient between flows. It allows simulating the back flow effect in onepipe radiator nodes. The results of calculations coincides with well-known literature data.Документ Geometric Analysis of Turbulent Macrostructure in Gets Laid on Flat Surfaces for Turbulence Intensity Calculation(University of Belgrade, Faculty of Mechanical Engineering, 2017) Gumen, Olena; Dovhaliuk, Volodymyr; Mileikovskyi, Viktor; Lebedieva, Olha; Dziubenko, VolodymyrEuropean Norms for ventilation contain turbulence intensity requirements in rooms. One of the determining factors is turbulence intensity in ventilation jets. We found an approach for geometric analysis of turbulent macrostructure for subsonic flows with large-scale vorticity i.e. ventilation jets and boundary layers between flows. This approach requires building of simplified turbulent macrostructure chart and performing geometrical analysis of it. In previous works, using the approach we analytically found averaged characteristic of free jets, jets in flows and jets laid on different shape surfaces without requirements of any experimental data. The results of geometrical analysis of heat transfer between flows are used in Ukrainian norms. In this work we found turbulence intensity of wall jets on flat surfaces such as room walls or ceiling without any experimental values. The results coincide with known experimental data and may be used in flow calculation in rooms.Документ Simplified analysis of turbulence intensity in curvilinear wall jets(University of Belgrade, Faculty of Mechanical Engineering, 2018) Dovhaliuk, Volodymyr; Gumen, Olena; Mileikovskyi, Viktor; Dziubenko, VolodymyrA simplified approach for estimation of turbulence intensity of turbulent submerged wall jets on cylindrical surfaces with different curvature is shown. It is a continuation of researches, performed by professor of Kyiv National University of Construction and Architecture Andrei Tkachuk. By using the geometric and kinematic analysis of turbulent macrostructure, it is proposed to found not only averaged flow characteristics but also turbulent pulsations. Analysis of visual researches of submerged jets in different works allows assuming such kind of flow as touching large round vortices (puffs), which roll by free flow boundary. In this work, geometric and kinematic analysis of this macrostructure chart in concave submerged wall jets is performed, and turbulence intensity is found. Results of the same analysis for submerged convex wall jets allow obtaining common dependencies for different curvature. The results are accepted by comparison with known experimental data.