This paper presents the inuence of geometry simplication on the results obtained in the computational fluid dynamics simulation. The subject of simulation was part of the honeycomb seal located at the inlet to high pressure part of a steam turbine. There were three different geometrical models assumed in the calculations. First one was two-dimensional case and two others were three dimensional, one with the radius of curvature and one without. Numerical simulations were performed for 15 sets of boundary conditions to compare ow characteristics for each geometrical case.
In this paper, the specified issues that occurs in the numerical modeling of complex phenomena of chemical reactions intensified with forced fluid flow in the thermocatalytic reactor channels on the intermetallic phase of Ni3Al are presented. Based on the example of flowing mixture containing helium contaminated by methanol in a horizontal microchannels, heated from the outside, received results of the experiment were shown and compared with computational fluid dynamize calculations. However, standard version of commercial code have been expanded by user defined functions. These extensions transformed the calculation mechanisms and algorithms of computational fluid dynamize codes adapting them for the micro-flow cases and increased chemical reactions rate on an interphase between fluid and solid. Results obtained on the way of numerical calculations were compared with experimental data receiving satisfactory compliance.
Centrifugal pumps working in reverse mode can be a good alternative for conventional water turbines. Prediction of the pumps as turbine characteristic curve is still complicated due to the lack of information provided by the producers and rare research focusing on this subject. In some cases of pumping systems it is important to estimate the operating point in turbine mode basing on pump test data. In this paper the pump characteristics in turbine mode for ten pumps with a speci c speed between 10 261 were compared and analyzed. The formulas used to predict the best performance point and characteristics of pump as turbine was reviewed. Own formulas for calculating optimum points of pump in the turbine mode was proposed.
