Наукові статті
Постійне посилання на фондhttps://repositary.knuba.edu.ua/handle/987654321/30
Переглянути
4 результатів
Результат пошуку
Документ New Approach for Refined Efficiency Estimation of Air Exchange Organization(Science Publishing Corporation, 2018) Dovhaliuk, Volodymyr; Mileikovskyi, ViktorIn the modern conditions, energy efficiency is one of the most important world problems. One of the important factors influencing the overall energy efficiency of buildings is air distribution in rooms. Literature review shows different options of efficiency estimation of air exchange with significant limitations. Some of them have non-obvious physical meaning. Certain of them do not take into account possible room zoning. Consideration of turbulence intensity in the efficiency estimation was not found. In this work, we propose an approach to estimate the air exchange efficiency in different kind of rooms. It is a relation of minimum room demands and inlet air potentials. Additional definitions are introduced for the parameters and demands estimation. The mechanical energy of the air is used for the estimation, which includes the energy of averaged motion and turbulent pulsation. Special approach is offered for turbulence intensity computation for energy calculations. The example of efficiency estimation of air exchange in a museum room with constant air volume system of air conditioning is solved.Документ New Approach for Estimation of Zonal Efficiency of Air Exchange Organization(Science Publishing Corporation, 2018) Dovhaliuk, Volodymyr; Mileikovskyi, ViktorEnergy efficiency of buildings is dependent on air exchange organization. There are different methods for efficiency estimation of it. As it is shown in literature review, they have significant limitations including non-obvious physical meaning, which cause problems in validation of the results. Certain of them are not acceptable for zonal ventilation in rooms. Previous author’s work introduces new approach for the efficiency estimation of air exchange in a single-zone or multi-zonal rooms, which has obvious physical meaning – relation of demands and supplied potentials. It provides the efficiency value for whole room only. In this work, by the similar approach, a method is proposed for estimation of zonal air exchange efficiency in different kind of rooms for each occupied zone separately. Additional definitions are introduced for the parameters and demands estimation in each occupied zone. The example of efficiency estimation of air exchange in a museum room with constant air volume system of air conditioning is solved. Sheltering of the keeping zone is recommended for the maximum air exchange efficiency.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.