• VISUALIZATION FLOW ON THEPELTON TURBINE BUCKET BY CFD

    Machines. Technologies. Materials., Vol. 12 (2018), Issue 6, pg(s) 244-247

    In this study, series of CFD simulation were carried out for two phase flow (free surface), three dimensional geometry and turbulent flow through the pelton turbine. The present investigation employed on the pelton turbine bucket models various splitter angle and inlet velocity values for visualizing the flow pattern and identifying the force on the bucket. In this study, Two different bucket models were applied at different inlet velocity (20, 25, 30,35and 40m/s) and four different splitter angle (55, 75,90and 115) for finding the effect of every single parameter on the effective force on the bucket. The obtained results discovered that there is a linear relationship between force and inlet velocity on the bucket. It uncovered that relationship between splitter angle and force on the bucket is linear until 90 degree after that this relationship is a non-linear.

  • NUMERICAL MODELING OF A SHELL-AND-TUBE HEAT EXCHANGER

    Machines. Technologies. Materials., Vol. 10 (2016), Issue 3, pg(s) 44-47

    The aim of this work is numerical modeling of the hydrodynamics and heat transfer of a shell-and-tube heat exchanger. For the purpose of the study a 3D model with geometric dimensions corresponding to real was created. The simulations under the same boundary conditions as experiment were carried out. The independence of solution by the density and the shape of the mesh were investigated. For verification the experimental values for fluid temperatures at the outlets from the apparatus were used. The simulations of different operation modes in the apparatus were carried out. A modification in the geometry with the aim of raising the temperature on the cold fluid at the outlet was made. Results on vectors, velocity and temperature distribution in the apparatus were obtained. On the basis of the obtained results some design changes of the apparatus in order to improve the hydrodynamics have been proposed. The obtained results can be successfully used in the design, optimization and constructing of this type apparatus, as well as in the educational process.

  • CFD MODELLING OF A COMPLETE ELECTRIC ARC FURNACE ENERGY SOURCES

    Innovations, Vol. 4 (2016), Issue 1, pg(s) 22-24

    This paper, concentrates on a three-dimensional (3D) computational fluid-dynamics (CFD) model for coal combustion and electrode radiation inside an electric-arc furnace (EAF). Simulation of the complete EAF model includes combustion reactions of coal particles and radiation from electrodes. Particle surface and gas phase reactions were used to predict injected coal particle combustion. The CFD model provided detail information for the coal particles combustion and radiation interactions phoneme inside the electric-arc furnace.

    Results showed that CFD simulation could efficiently be used to develop and investigate EAF in design phase.

  • CFD MODELING OF TURBINE FLOW METERS

    Innovations, Vol. 2 (2014), Issue 1, pg(s) 6-8

    Computational fluid dynamics (cfd) techniques provide investigations in conditions where the real experiment can’t be fulfilled for some reason, so these tools have found their applications in many spheres of science and technology; in particular they are widely used in flow metering.

    Some of CFD applications we would like to propose and discuss in this work in the context of turbine flow meters. We discover non-drag type of turbine flow meters to check if created design with hydro-dynamic bearings should provide really floating rotor. For this purpose only numerical research can solve verification problem with minimal costs and simple realisation.

    CFD models are used to examine pressure contours and velocity profiles near floating rotor in turbine flow meters. A full three-dimensional flow simulation of realistic meter configurations has been carried out. Close attention was paid to simulation of the complete geometry of turbine meters including front-end and tail-end shapes of flow conditioner hub, metering cells, etc. Some advices to meters’ designing were given.