Now showing items 1-20 of 36

  • 2D Model of Capillary Transport of Water in Aerated Concrete 

    Šikula, Ondřej; Mohapl, Martin (Trans Tech Publications, 2013-01-08)
    Saturation degree of aerated concrete strongly affects not only all its thermal-technica properties, but regarding to the risk of freezing, also the strength properties. The aim of this paper is to discuss existing approaches ...
  • Adaptive fan control 

    Blasinski, Petr; Rubina, Aleš; Rubinová, Olga; Jůza, Štěpán (IOP Pulishing, 2021-07-28)
    The paper presents the possibility of management the fan performance in dependence on CO2 concentration. A mathematical calculation is made from the prediction of the electric energy consumption for a variant control ...
  • Adjusting the design of a radiant heating system for office retrofit 

    Junášová, Barbora; Šikula, Ondřej; Krajčík, Michal; Arici, Müslüm; Šimko, Martin (TU Delft, 2022-05-16)
    Installation of low-exergy water-based radiant systems can help alleviate the negative effects of increased energy consumption due to their suitability for combination with low-grade renewable energy sources. Radiant heating ...
  • Analysis of local moisture increase of timber constructions on ice arena roof 

    Žák, Antonín; Šikula, Ondřej; Trcala, Miroslav (Trans Tech Publications, 2013-01-08)
    Timber is one of the most used materials for roofing of ice arena because of its very good mechanical properties and low weight. High relative humidity of internal air, low temperature and ice rink presence, which cause ...
  • Assessment of condensation of water vapor in the mixing chamber by CFD method 

    Vojkůvková, Petra; Šikula, Ondřej; Weyr, Jan (EDP Sciences, 2015-05-06)
    The analyzed topic belongs to the field of design and operation of HVAC systems, focusing mainly on mixing chambers. The paper deals with problems of condensation and freezing of water vapour on walls of mixing chambers ...
  • Circular Free Jets: CFD Simulations with Various Turbulence Models and Their Comparison with Theoretical Solutions 

    Kmecová, Miroslava; Šikula, Ondřej; Krajčík, Michal (IOP Publishing Ltd, 2019-02-25)
    The theory of turbulent free jet is fundamental for the design of comfort ventilation, as free jets frequently occur in mixing and personalized ventilation systems and their characteristics strongly influence the air quality ...
  • The Effect of Shielding Barriers on Solar Air Collector Gains 

    Šikula, Ondřej; Plášek, Josef; Hirš, Jiří (Elsevier, 2013-08-22)
    The paper deals with numerical simulations of the impact of location and orientation of the solar air collector located on the roof of a building and on its thermal performance. The solar collector is used to preheat an ...
  • Efficiency of Parallel Connected Desuperheater in a Cooling Circuit 

    Formánek, Marian; Horák, Petr (Budapest University of Technology and Economics, 2022-10-27)
    Cooling circuits can be improved by using a desuperheater. A series connected desuperheater increases the efficiency of the circuit and allows the waste heat to be used, e.g., for DHW preparation. The study investigates ...
  • Energy, economic and environmental analysis of opened natural healing water source 

    Miček, Denis; Hirš, Jiří (EDP Sciences, 2019-08-13)
    European´s low carbon economy is the main target in the way of the reducing greenhouse gases at the Earth´s atmosphere. The most promising way is in maximal usage of renewable sources of energy such as geothermal energy, ...
  • Energy-Pile Model Verification 

    Šikula, Ondřej; Slávik, Richard; Eliáš, Jan; Oravec, Jakub; Kašpar, Antonín (KGH, 2020-12-31)
    Equipping the foundation piles with a liquid circuit pipeline makes it possible to use the advantageous thermal capacity of the soil for heating and cooling buildings at low cost. The energy performance of the energy-pile ...
  • An Evaluation of the Mathematical Models of Energy Piles 

    Oravec, Jakub; Šikula, Ondřej; Nováková, Iva (Sciendo, 2020-04-03)
    A current trend is to reduce the energy performance of buildings by using alternative sources for heating and cooling. One of the most promising, and so far unprecedented sources of heating and cooling, is the use of energy ...
  • Experimental Analysis of Steam Condensation in Vertical Tube with Small Diameter 

    Kubín, Milan; Hirš, Jiří; Plášek, Josef (Elsevier, 2016-01-12)
    Thermal design of tubular heat exchanger based on condensation heat of water steam requires knowledge of condensation heat transfer in the each tube. This paper is just aimed on experimental analysis of steam condensation ...
  • Experimental and numerical study of turbulent flow around a Fanwings profile 

    BENFERHAT, Slimane; Tayeb, Yahiaoui; IMINE, Bachir; Ladjedel, Omar; Šikula, Ondřej (Taylor & Francis Group, 2019-07-20)
    The main objective of this paper is an experimental and numerical study of airflow on a propulsive wing also called ventilated wing or FANWING, which is a drone operating at low speed. To optimize the aerodynamic shape of ...
  • Experimental Increase in the Efficiency of a Cooling Circuit Using a Desuperheater 

    Formánek, Marian; Horák, Petr; Diblík, Josef; Hirš, Jiří (Budapest University of Technology and Economics, 2016-05-02)
    Waste heat from cooling circuits can be a useful source of energy for other applications, such as domestic hot water heaters. Furthermore, by removing waste heat from the cooling circuit, its effectiveness can theoretically ...
  • Feasibility of Using Energy Performance Contracting for the Retrofit of Apartment Buildings in Slovakia 

    Gombošová, Veronika; Krajčík, Michal; Šikula, Ondřej (Sciendo, 2022-09-01)
    This study is focused on the feasibility of using energy performance contracting (EPC) for the retrofit of two apartment buildings constructed using precast concrete technologies in Slovakia decades ago. The retrofit ...
  • Fluid thermal effect on non-contacting labyrinth seal of 20 MW steam turbine 

    Mammar, Lahouari; Tayeb, Yahiaoui; Ladjedel, Omar; Šikula, Ondřej (Faculty of Mechanical Engineering of the Budapest University of Technology and Economics, 2019-12-17)
    This paper is divided into two parts; the first describes a CFD analysis of a gland packing labyrinth seals in 20 MW steam turbine in LNG plant using ANSYS CFX code as an isothermal simulation in fluid domain. The results ...
  • Hybrid Roof Panels for Night Cooling and Solar Energy Utilization in Buildings 

    Šikula, Ondřej; Vojkůvková, Petra; Šíma, Jiří; Plášek, Josef; Gebauer, Günter (Elsevier, 2015-08-28)
    The aim of this contribution is to evaluate the usability of solar hybrid panels, which were originally optimized for heat load removal from buildings by radiation against the night sky, for water preheating. First we ...
  • Impact of IPPC Scenarios on indoor environment quality of historic buildings 

    Weyr, Jan; Hirš, Jiří; Kalný, Richard (EDP Sciences, 2019-08-13)
    Ensuring proper indoor environment quality in buildings with historic value or buildings located in historic centres of cities is not an easy task. These buildings are frequently listed in historic preservation lists; thus, ...
  • Implications of Model Complexity for the Simulated Thermal Behavior of a Casement Window 

    Khosravi, Shiva; Šikula, Ondřej; Pont, Ulrich; Mahdavi, Ardeshir (IOP Publishing, 2019-06-27)
    Windows have been a subject of interest for research in building industry due to their multifaceted and significant implications for indoor environmental quality and energy use. In this context, the present contribution ...
  • Model dynamického tepelného chování konstrukčních detailů 

    Šikula, Ondřej (IBPSA-CZ, ČVUT, 2008-11-06)
    Podstatou příspěvku je prezentace nového výpočetního modelu určeného pro dynamickou simulaci přenosu tepla v konstrukčních detailech stavebních konstrukcí. Vlastní výpočetní model je založen na numerickém řešení dvourozměrného ...