Now showing items 5-24 of 28

  • Check valve slam analysis in pumping station 

    Himr, Daniel; Habán, Vladimír; Dokoupil, Pavel (EDP Sciences, 2016-03-28)
    Pumping station supplies water for technological process. The check valve in the station was replaced with a new one. The regular test of black out discovered the high pressure pulsations accompanied with noticeable pipeline ...
  • Comprehensive Study Of Unsteady Pressure Pulsations Induced By The Spiral Vortex Structure In A Conical Diffuser 

    Štefan, David; Rudolf, Pavel; Hudec, Martin; Habán, Vladimír (Faculty of Technologies and Systems, 2015-09-09)
    The decelerated swirling flow often breaks down into helical structure which is unstable and causes unsteady velocity and pressure fields. The numerical and experimental investigation of this flow pattern is carried out ...
  • Design of a high-specific speed turbine with non-uniform blade cascade 

    Stareček, Jakub; Čupr, Pavel; Haluza, Miloslav (EDP Sciences, 2019-06-28)
    This paper presents the hydraulic design of Kaplan type turbine in fully axial configuration. The turbine model consists of a straight pipe intake, a rib which covers the shaft, five axial guide vanes, a six blade runner ...
  • Design of hydraulic recuperation unit 

    Jandourek, Pavel; Habán, Vladimír; Hudec, Martin; Dobšáková, Lenka; Štefan, David (EDP Sciences, 2015-11-17)
    Article deals with design and measurement of hydraulic recuperation unit. Recuperation unit consist of radial turbine and axial pump, which are coupled on the same shaft. Speed of shaft with impellers are 6000 1/min. For ...
  • Dynamics of pressure pulsations in thin annular gap 

    Kůrečka, Jan; Himr, Daniel; Habán, Vladimír (IOP Publishing, 2021-06-15)
    Fluid pulsations can significantly influence behavior of bearings or sealing parts of hydraulic machines and therefore their operation. In this contribution, an analytical approach to solve pressure pulsations dynamics is ...
  • Effect of Splitter Blades on Performances of a Very Low Specific Speed Pump 

    Chabannes, Lilian; Štefan, David; Rudolf, Pavel (MDPI, 2021-06-24)
    The usage of splitter blades to enhance the performances of low specific speed pumps is common practice. Based on experimental and numerical studies, the influence of the addition of one and two splitter blades is investigated ...
  • Experimental analysis of static and dynamic properties of the check valves 

    Dokoupil, Pavel; Himr, Daniel; Habán, Vladimír (EDP Sciences, 2019-06-28)
    The check valves play an important role in safety and reliability of many technologies using liquid or gas flow. Check valves are elements of the hydraulic system enabling the one-way flow without a significant pressure ...
  • Experimental investigation of check valve behaviour during the pump trip 

    Himr, Daniel; Habán, Vladimír; Hudec, Martin (IOP Publishing, 2017-04-04)
    The paper is focused on the description of an experimental investigation of a nozzle check valve. Attention is paid to the behaviour during transitions when the flow is decelerating. Flow reversal is often accompanied with ...
  • Experimental investigation of swirl number influence on spiral vortex structure dynamics 

    Štefan, David; Hudec, Martin; Uruba, Václav; procházka, pavel; Urban, Ondřej; Rudolf, Pavel (IOP Publishing, 2021-06-15)
    The hydraulic turbines are recently forced to operate far away from the optimal conditions in order to balance fluctuations in electricity generation. In case of Francis, pump and propeller turbines, using only single ...
  • Experimental investigation of the check valve behaviour when the flow is reversing 

    Himr, Daniel; Habán, Vladimír; Hudec, Martin; Pavlík, Václav (EDP Sciences, 2017-05-12)
    Check valve in a pipeline is supposed to prevent the reverse flow and to allow the flow in the positive direction. The construction of check valves follows these requirements, but the check valve must not cause pressure ...
  • Flow Inside the Sidewall Gaps of Hydraulic Machines: A Review 

    Zemanová, Lucie; Rudolf, Pavel (MDPI, 2020-12-15)
    The paper critically reviews the current state of the art in flow inside sidewall gaps of hydraulic pumps and turbines. It describes the consequences of the presence of this type of flow in turbomachinery and then relates ...
  • FSI Computation and Experimental Verification of Fluid Flow in Flexible Tubes 

    Šedivý, Dominik; Fialová, Simona; Klas, Roman; Kotek, Michal (Sciendo, 2020-07-24)
    Presented paper is focused on the experimental and computational study of fluid flow in pipes with flexible walls. One possible real example of this phenomenon is the blood flow in arteries or their substitutes in the human ...
  • Influence of Second Viscosity on Pressure Pulsation 

    Himr, Daniel; Habán, Vladimír; Fialová, Simona (MDPI, 2019-12-12)
    A mathematical model of pulsating flow is proposed in the paper. The model includes more accurate description of energy dissipation, so it allows, for example, better stability analysis of water power plant control and ...
  • Inner Damping of Water in Conduit of Hydraulic Power Plant 

    Himr, Daniel; Habán, Vladimír; Štefan, David (MDPI, 2021-06-25)
    The operation of any hydraulic power plant is accompanied by pressure pulsations that are caused by vortex rope under the runner, rotor–stator interaction and various transitions during changes in operating conditions or ...
  • An Investigation of Viscous Torque Loss in Ball Bearing Operating in Various Liquids 

    Dobrovolný, Martin; Habán, Vladimír; Tancjurová, Jana; Zbavitel, Jan (MDPI, 2021-05-08)
    The limited functionality of seals that are used in hydraulic machines to prevent the liquid from leaking into the bearings may result in decrease in machine efficiency and reliability and may cause an accident of the whole ...
  • Manipulation of the swirling flow instability in hydraulic turbine diffuser by different methods of water injection 

    Rudolf, Pavel; Litera, Jiří; Ibarra Bolanos, Germán Alejandro; Štefan, David (EDP Sciences, 2018-06-04)
    Vortex rope, which induces substantial pressure pulsations, arises in the draft tube (diffuser) of Francis turbine for off-design operating conditions. Present paper focuses on mitigation of those pulsations using active ...
  • Mass Production of Plasma Activated Water: Case Studies of Its Biocidal Effect on Algae and Cyanobacteria 

    Čech, Jan; Sťahel, Pavel; Ráheľ, Jozef; Prokeš, Lubomír; Rudolf, Pavel; Maršálková, Eliška; Maršálek, Blahoslav (MDPI, 2020-11-12)
    Efficient treatment of contaminated water in industrially viable volumes is still a challenging task. The hydrodynamic cavitation plasma jet (HCPJ) is a promising plasma source for industrial-scale generation of biologically ...
  • Methods of Experimental Investigation of Cavitation in a Convergent - Divergent Nozzle of Rectangular Cross Section 

    Jablonská, Jana; Kozubková, Milada; Himr, Daniel; Weisz, Michal (De Gruyter Open, 2016-08-01)
    Cavitation is a phenomenon with both positive and negative effects and with dynamic manifestations in hydraulic, food, chemical and other machinery. This article deals with the detection and dynamic behavior of cavitation ...
  • A new form of equation for force determination based on Navier-Stokes equations 

    Fialová, Simona; Pochylý, František; Šedivý, Dominik (EDP Sciences, 2018-11-12)
    This work is focused on calculating the force effects of an incompressible homogeneous liquid on a surface of a rigid or a flexible tube. An unsteady flow induced by differential pressure at the beginning and at the end ...
  • Removal of Microcystis aeruginosa through the Combined Effect of Plasma Discharge and Hydrodynamic Cavitation 

    Maršálek, Blahoslav; Maršálková, Eliška; Odehnalová, Klára; Pochylý, František; Rudolf, Pavel; Sťahel, Pavel; Ráheľ, Jozef; Čech, Jan; Fialová, Simona; Zezulka, Štěpán (MDPI, 2019-12-18)
    Cyanobacterial water blooms represent toxicological, ecological and technological problems around the globe. When present in raw water used for drinking water production, one of the best strategies is to remove the ...