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Modelling of flow over two transversal ribs in a channel with free surface
Sládek, A. ; Příhoda, Jaromír ; Stanislav, Jiří
Numerical simulation of turbulent flow over two transversal ribs on the bottom of a channel with free surface was carried out. The VOF (Volume-of-Fluid) method implemented in the commercial software FLUENT 6.3 was used for the solution of supercritical flow in a channel with free surface. The two-equation turbulence model according to Shih et al. was applied. The simulation was realised for ribs with the relative spacing t/b = 6; 10 and 20. Profiles of mean velocity and velocity fluctuation obtained by numerical simulation were compared with experimental data from LDA and PIV measurements. The behaviour of free surface over ribs was compared with experiments as well.
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Numerické řešení stacionárního a nestacionárního proudění kolem profilu v kanálu
Furmánek, P. ; Horáček, Jaromír ; Kozel, Karel
The work deals with steady and unsteady solution of subsonic flow over a profile DCA 18%in a channel. For the computation the predictor-correstor MacCormack scheme with modified TVD Cousonś artificial dissipation is used. Firstly, the steady state solution compared to the experimental results is presented. Than a simple unsteady model based on pressure change at the outlet area of the computational domain and finaly an unsteady model obtained with the use of ALE method (moving mesh) are presented.
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Interakce proudění v kanále s pohybujícími se tělesy
Růžička, M. ; Feistauer, M. ; Horáček, Jaromír ; Sváček, Petr
The subject of this paper is the numerical simulation of the interaction of two-dimensional incompressible viscous flow through a channel (wind tunnel) and a vibrating airfoil. A solid airfoil with two degrees of freedom, which can rotate around the elastic axis and oscillate in the vertical direction, is considered. The numerical simulation consists of the finite element soulution of the Navier-Stokes equations coupled with the system of ordinary differential equations describing the airfoil motion. We discuss the discretization of the problem and present some computational results.
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Vyšetřování charakteristik ventilátoru použitého jako zdroj vzduchu v experimentálním zařízení pro zkoumání šroubovicových nestabilit v proudících tekutinách
Tesař, Václav ; Kukačka, Libor ; Kellnerová, Radka
For investigations of aerodynamic properties of helical instabilities in flowing fluids, an experimental rig is currently built. It is intended on the one hand for visualisations of acoustically excited helical structures and on the other hand for model experiments with flows of cyclonal character. As the universal air source for both purposes, a blower is used for which no loading characteristics were available - and which, at any rate, is to be operated in some of the regimes at very low Reynolds numbers where one has to expect deviation from characteristics obtained under standard conditions. The authors investigated the blower loading characteristics experimentally and used this opportunity to apply and test practical validity of the general ideas about universal representation of characteristics and criterial similarity parameters of turbomachines, published considerable time ago but seemingly little known and used.
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