• EXPERIMENTAL AND NUMERICAL ANALYSIS OF WIND TURBINE MODEL

    Machines. Technologies. Materials., Vol. 13 (2019), Issue 5, pg(s) 206-209

    Global demand for electric energy is predicted to increase in the coming decades. Following this, different approaches for additional electricity production are analysed and tested worldwide. The EU supports the production and usage of electricity from renewable energy sources, particularly wind energy, because it provides electricity without giving rise to any carbon dioxide emissions. The presented work analysis the possibility for utilising of wind-generated electricity as a stand-alone system for small off grid cabin supply. The very basic turbine geometry was designed and numerically simulated with commercial CFD software. After that, the turbine model was printed using 3D printer and tested in laboratory environment. The comparison of numerically and experimentally obtained operating characteristics show reasonable agreement and strong potential for system optimisation and improvements.

  • SIMULATION OF THREE-DIMENSIONAL CAVITATION IN RADIAL DIVERGENT TEST SECTION USING DIFFERENT MASS TRANSFER MODELS

    Mathematical Modeling, Vol. 3 (2019), Issue 1, pg(s) 21-24

    Cavitation is a phenomenon of liquid transition to vapour which occur at sudden drop in pressure. It can be studied experimentally using visualization techniques or numerically using numerical packages. In order to numerically predict cavitation Reynolds Averaged Navier Stokes equations and an additional transport equation for the liquid volume fraction can be used. In the additional transport equation mass transfer rate due to cavitation is modelled using different mass transfer models. In the presented paper cloud cavitation in radial divergent test section was studied numerically using three different widespread mass transfer models. The models used were Zwart, Kunz and Singhal mass transfer models. Zwart model is a native model of ANSYS CFX program while other two were implemented to the program. Steady state and transient RANS simulations were performed using the simulation program, standard k-e turbulence model and scalable wall functions. The results of numerical simulations were compared with the results of experimental measurements performed at the University of Grenoble. Based on the presented results we concluded that all mass transfer models correctly predict the area of cloud cavitation formation.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    EXPERIMENTAL ANALYSIS OF BRAKE DISC COOLING CAPACITY

    Trans Motauto World, Vol. 2 (2017), Issue 4, pg(s) 140-142

    The car brake system performance has to be reliable at wide range of operating conditions. The friction based braking system reliability strongly depends on cooling capability of disc. According to this, different testing is needed to assure the performance of discs during their design and prototyping phase. The contribution presents the study of cooling capacity of different vented brake disc geometries. Brake disc temperatures during thermal capacity test can exceed 600 C. The temperatures are highly dependent on disc cooling capability. Vented disc have higher cooling capability. There is an open issue which factor has the most significant impact. Is it air flow, air flow distribution, turbulence or …? Brake discs with the same external geometry but different internal geometry were tested on brake dynamometer and subsequently air flow parameters were analysed in cold condition to attempt to explain different maximum temperatures.

  • TRANSPORT TECHNICS. INVESTIGATION OF ELEMENTS. RELIABILITY

    EXPERIMENTAL ANALYSIS OF BRAKE DISC COOLING CAPACITY

    Trans Motauto World, Vol. 2 (2017), Issue 2, pg(s) 58-60

    The car brake system performance has to be reliable at wide range of operating conditions. The friction based braking system reliability strongly depends on cooling capability of disc. According to this, different testing is needed to assure the performance of discs during their design and prototyping phase. The contribution presents the study of cooling capacity of different vented brake disc geometries.

    Brake disc temperatures during thermal capacity test can exceed 600 C. The temperatures are highly dependent on disc cooling capability. Vented disc have higher cooling capability. There is an open issue which factor has the most significant impact. Is it air flow, air flow distribution, turbulence or …? Brake discs with the same external geometry but different internal geometry were tested on brake dynamometer and subsequently air flow parameters were analysed in cold condition to attempt to explain different maximum temperatures.