Abstract. The contribution using CFD system ANSYS/FL flow parts flow and selected velocity profiles in smooth p selected results of the numer partially comparison with exp

Abstract. The article deals with a description of results from research and development of a radial compressor stage. The experimental compressor and used numerical models are briefly described. In the first part, the comparisons of characteristics obtained experimentally and by numerical simulations for stage with vaneless diffuser are described. In the second part, the results for stage with vanned diffuser are presented. The results are relevant for next studies in research and development process.

No abstract

The contribution deals with the numerical simulation of air and steam flow through the model of control valve for steam turbines. Numerical simulations were compared with experimental measurements for the award of the same boundary conditions. Valve characteristics have been computed for individual travel heights and pressure ratios of two variants of seat inflow angle (90° and 60°). Some other aspects are discussed in the article-comparison of the axysymmetric and 3D modelling, influence of the computational domain size, comparison of characteristics for two flow media, experimental model of the valve etc. The mentioned results are important for engineering simulations and also for design of the control valves for steam turbines of the large output. The control valve in a steam turbine is a main component included in the turbine set. This system comprises control fittings (i.e. valves, screens or control partitions) that control the flow of steam into the turbine. The system includes valve control (i.e. servos or HP hydraulic system) which sets the valves and screens to the required flow rate and pressure of the steam. It also contains an electronic system with control software which enables setting the valves, i.e. changing the steam flow into the turbine and thus changing the turbo-set output, from the control centre. The control valve should reliably regulate the amount of steam flow and thus the turbine set output. The actual regulation is achieved by a change of the flow area between the plug and the valve seat. The control valve design is outlined in Figure 1. These valves are produced in many versions with various arrangements and plugs.

Abstract. Numerical simulation of the flow behavior in part of large pipe system is presented in this article.Compressed natural gas is transported through the system in a dynamic unsteady way. Velocities at several points and velocity profiles at certain positions are monitored during the numerical simulation. The aim is to investigate the stability of velocity profiles at the positions of flowmeters in course of flow time. In addition, the possibility of flow conditioning in the system is presented and discussed.