Applied Mechanics and Materials Vol. 630

Abstract: This article presents the analysis of the flow pattern in the vanes diffuser with discontinuous crossover channels. We observe design features of the crossover channels and their influence on the flow pattern

Abstract: This article observes the research results of flow behavior in the impeller chamber of the double suction centrifugal pump. On the basis of the research results we have determine the values of static and dynamic component of axial force.

Abstract: Research of centrifugal pumps’ workflow through their modeling is made. The methods of modeling such processes are viewed: by traditional numerical method and by proposed purely electrical methods of modeling. By comparing modeling results with test results the adequacy of modeling by purely electrical methods is proved.

Abstract: The theses present results of a study of a small-sized axial-flow stage with blades of small aspect ratio, which is designed for submersible borehole pumps. The energy losses in the flow section of stage are analyzed in research. Refined equations of total hydraulic losses for these flow parts were received by numerical simulation. The results of numerical simulation are compared with experimental data.

Abstract: Topic related to an impeller - diffuser hydraulic interaction is important especially in term of energy transformation and performance parameters. A connection of particular functional parts is one of the most important design factors which determine a shape of performance parameters and efficiency. The stated problem is possible to discuss in two possible ways. In term of internal flow pattern and in term of external pump parameters which are represented by performance curve courses. The contribution deals with the influence of the change of the impeller - axial diffuser interaction on quantitative courses of specific energy and efficiency curves.

Abstract: Torque flow pumps are widely used for pumping of fluids with high content of solid and fibrous inclusions and gas bubbles, in particular, for pumping of sewage and wastes. Fluid flow in these pumps is featured with strong vortex patterns, making it difficult to predict reliably their performance curves numerically. The paper is devoted to selection of a numerical approach for simulation of fluid flow in a torque flow pump of “Turo” type and its influence on simulation results. In particular, influence of geometrical configuration of the rotor-stator interface as well as numerical grid fineness is demonstrated. For one geometric configuration, the fluid flow is simulated with different turbulent models, with a steady state as well as transient approach. The simulations were performed using the software product ANSYS CFX. The simulation results are compared with the experimental measurements in the torque flow pump of “Turo” type. The experimental research included probing of fluid flow in three cross-sections of the stator domain, visualizing of streamlines along the rotating and stationary walls, as well as obtaining of performance curves. A good agreement between the numerical and experimental results is obtained as the rotor-stator interface is located at some distance off the rotating parts. Influence of choice of the turbulence model on the simulation results is demonstrated. Conclusions and recommendations are made concerning the choice of initial and boundary conditions, geometrical configuration of the rotor-stator interface, and parameters of turbulence models that affect both the flow pattern in the pump and its performance curves as well as the numerical solution time and required computational resources.

Abstract: The radial labyrinth pump consists of two discs: passive and active. Both discs are equipped in special blades with the opposite angle of milling. The passive disc is motionless and the active one rotates around the axis of the pump. On the surface of the connection of two blades belonging to different discs the circulation of fluid, as a type of energy conversion is expected. To investigate the analysed set of discs and take into consideration the impact of some structural changes of the geometry of both discs on a pump performance the numerical simulations were made. In this paper the results of CFD research of the flow in the radial labyrinth pump are presented.

Abstract: The potential and features of thermotransformer operation has been investigated with the employment of jet thermal compression in heat pump or refrigeration cycles. Jet thermal principle is realized by means of injection and compression of the low-pressure steam with the help of working steam jet. It is formed with the help of relaxation vaporization of the subcooled liquid inside motive flow duct of jet compressor instead of the conventional mechanical compressor. It is a part of the jet thermal compression module which includes a liquid-vapor jet compressor, a separator, a pump and a heater. Perspective of application the ammonia-water mixture as working substance is determined by its high thermodynamic and environmental properties, possibility to maintain higher condensation temperatures than when using CFC, HCFC and HFC chemicals.

Abstract: This article concerns a global world problem of the mankind – energy problem. One of the possible ways of solution is utilization of compressed gases energy using installations based on a jet-reactive turbine in different branches of industry. This work is dedicated to software application when processing calculation procedure on different turbine operation modes and comparison with the results of the experimental researches.