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Střihové napětí na stěně pod velkou bublinou stoupající v nakloněném plochém kanále
Tihon, Jaroslav ; Pěnkavová, Věra ; Vejražka, Jiří
The motion of single air bubbles in an inclined flat water channel is investigated experimentally. The electrodiffusion technique of near-wall flow diagnostics is applied to measure the wall shear stress distribution under large bubbles rising along the upper channel wall. The electrodiffusion measurements are synchronized with the visual observation of bubble movement done by a high-speed camera. The analysis of video records provides information on the bubble shape and terminal velocity. The experiments are carried out for three different channel heights and cover a wide range of channel inclination angles (from horizontal to vertical position). The experimental results on bubble motion characteristics obtained in stagnant and upward-flowing liquid arrangements are confronted with the recent predictions and scaling provided by theoretical models.
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Proudění v okolí Ahmedova tělesa
Uruba, Václav ; Sedlák, K.
Flow in wake of a car model was studied experimentally in a wind channel. The model was designed on the basis of so called Ahmed body in ratio 3 : 20, width of the model was from wall to wall, no gap, prismatic shape. We concentrated out our attention on upper rear part of the model, separation of the boundary layer from roof and formation of the wake. The upper part of the wake forming a free shear layer was studied in detail. Two variants of the model with slant angles = 25° and 35° was examined respectively. Angle 25° shows more or less attached flow, while angle 35° generates fully detached flow from the ramp.
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WP5 Status Report Months 31 to 50
Křišťál, Jiří ; Stavárek, Petr ; Jiřičný, Vladimír
Within WP5 in this reporting period focused on the development of a new intensified reactor concept for sulph(on)ation reaction. Based on the previous hydrodynamic experiments and mathematical models we designed a new reactor – microSulphonator. We also constructed and manufactured several prototypes that were later tested with model fluids. Experimental data were used for the validation of the models defined previously. Results of this period served as a basis for the final microSulphonators to be tested in the PGB pilot plant during the demonstration phase of the F3 project.
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Finite element modelling of viscous incompressible fluid flow in glottis
Damašek, Alexandr ; Burda, P.
he paper deals with numericalcomputations of viscous incompressible fluid flow in glottis describedby Navier-Stokes equations and discretized bythe finite element method. Navier-Stokes equations with the nonlinearterm are discretized by semiimplicit integration scheme. Forhigher Reynolds number fluid flow Streamline Upwind Petrov-Galerkin Method - SUPG. This method uses special weight functions which modify shape functions based on the Galerkin principle.
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