Národní úložiště šedé literatury Nalezeno 6 záznamů.  Hledání trvalo 0.01 vteřin. 
Study on Performance of Various Turbulent Heat Transfer Closures
Louda, Petr ; Příhoda, Jaromír
The work compares results of several turbulent heat flux models with different complexity. Authors consider eddy diffusivity model as well as generalized gradient hypothesis and explicit algebraic closures. The results are obtained for backward facing step with heated bottom wall and compared with measurements.
Dynamics of secondary flow behind backward-facing step in a narrow channel
Uruba, Václav
Dynamics of the flow-field behind a backward-facing step in a narrow channel is studied experimentally using time resolved PIV technique. Secondary flow represented by vortical structures is studied using Oscillation Pattern decomposition technique. The low-frequency quasi-periodical structures appearing in the region just behind the step close to the channel bottom are studied. Typical dynamics of vortex structures involving contra-rotating vortex pair train, vortices coalescence and splitting have been observed.
On the Reynolds number role in structure of recirculation zone b ehind backward facing step in a narow channel
Uruba, Václav
Topology of the time-mean flow-field behind the backward facing step in a narrow channel is presented for various Reynolds numbers. The flow-field is studied in planes close to the channel bottom and in the plane of symmetry. Special attention is devoted to the appearance of secondary and higher order structures defined on the time-mean basis. Experimental results are obtained from PIV measurements.
Some Results of Simulations of 3D Backward Facing Step
Louda, Petr ; Kozel, K. ; Příhoda, Jaromír
The paper deals with numerical simulation of 3D incompressible flow over backward facing step. The RANS technique is used with an explicit algebraic Reynolds stress turbulence model. The numerical solution is achieved by implicit finite volume method. The results are compared with measurement.
On structure of recirculation zone behind backward-facing step in a narrow channel
Uruba, Václav
The time mean structure of the flow behind a step in a narrow channel was shown. The footprint behind the step is not connected with vortical structures, as formulated in older studies, but the low pressure generation close to the channel bottom in the recirculation region seems to be more relevant.
Řízení vyfukováním odtrženého proudu v kanálu se schodovitým rozšířením
Jonáš, Pavel ; Mazur, Oton ; Uruba, Václav
Příspěvek se zabývá možností řízení pomocí vyfukování/odsávání štěrbinou u paty schodu v proudění úzkým kanálem. Štěrbiny se lišily plochou a tvarem (obdélníkový nebo pilovitý)průřezu.

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