National Repository of Grey Literature 9 records found  Search took 0.01 seconds. 
Prediction of turbulent flow over the inclined step by means of various two-equation turbulence models
Janeček, Vladislav ; Příhoda, Jaromír
The work deals with the numerical simulation of turbulent flow over an inclined step in a channel of the rectangular cross-section according to measurement of Makiola (1992). The simulation was carried out by means of the commercial software ANSYS FLUENT with users defined functions. Various two-equation turbulence models based on the k-eps formulation were tested with the aim to estimate their ability to predict the extent of the separation region and energy losses due to inclined step with the angle 15 deg. Numerical results were compared with experimental data from LDA measurements. Besides, determined energy losses were compared with losses in a channel with a backward-facing step.
Řízení mezní vrstvy na profilu s vychýlenou klapkou pomocí vírových generátorů
Součková, Natálie ; Šimurda, David ; Popelka, Lukáš
The paper focuses on reducing eventually removing flow separation, which is occurred on deflected flap, with vortex generators. Airfoil NACA 63A421 with simple flap and low profile vane-type vortex generators were used. The investigation was carried out using experimental and numerical method. The flow over the airfoil was visualized by tuft filaments technique in closed circuit wind tunnel for two flap deflections and four angles of attack. Two size and two different shapes of vortex generators were tested. The data from numerical simulation of flapped airfoil without VG's control were used for vortex generator designing.
On Wakes in an Asymmetric Supersonic Flow Past Trailing Edges of a Profile Blade Cascade
Šafařík, Pavel ; Šimurda, David
Paper is concerned with results of research on the asymmetric supersonic flow past trailing edge. Distributions of the exit flow angle are compared to theoretical and reference value.
Numerická simulace aerodynamické interakce křídla a trupu
Šimurda, David ; Popelka, Lukáš ; Zelený, L. ; Matějka, Milan
In order to investigate and understand extent of the wing-body interaction effects taking place during operation of a particular self-launching sailplane, commercial code Fluent 6.3 was used for numerical simulation of flow past a simplified model of TST-10a. Several methods were used to identify vortex structures originating due to interference effects in this part of the aircraft. 3D effects and distortions of pressure and velocity distributions taking place in the junction of the body and the fuselage were observed.
Numerické řešení proudění v turbínové mříži s užitím různých modelů turbulence
Fořt, J. ; Dobeš, J. ; Fürst, J. ; Halama, J. ; Kozel, K. ; Louda, Petr ; Příhoda, Jaromír
The paper shows examples of the use of in-house developed numerical codes in the design procedure of a turbine blade cascade. Numerical results of the flow field in axial turbine stator cascade with alternative shapes of blade profiles achieved by these codes are presented. Further, effects of grid, numerical scheme and turbulence model on numerical results are discussed. A model of laminar/turbulent transition together with preliminary numerical results for flow through a stator turbine cascade is also presented.
Měřicí prostor pro profily a tělesa, studie proveditelnosti výzkumného projektu
Popelka, Lukáš
Article describes new 865x485x900mm3 test section of closed-circuit wind tunnel IT AS CR for airfoils and bodies, respectively. These setups are arranged primary for three-component aerodynamic balance and visualization techniques access. Prepared research programme aimed at reference measurements, outer stream turbulence, flow control and surface roughness influence on boundary layer transition and separation is presented.
Experimentální výzkum transsonického proudění v 2-D modelu těsnící mezery
Luxa, Martin ; Dvořák, Rudolf ; Šimurda, David ; Vimmr, J.
The paper deals with experimental modelling of the flow through the 2-D model of the male rotor sprocket - housing gap in a screw compressor. The optical schlieren method was used as well as the pneumatic measurement methods.
Implementace algebraického modelu zkráceného přechodu do dvourovnicového modelu turbulence pro řešič založený na metodě konečných objemů
Dobeš, J. ; Fořt, J. ; Příhoda, Jaromír
A mathematical model of turbulent flow, based on the finite volume method and two-equation turbulence model, was extended by an algebraic model of the bypass transition taking into account the effect of free-stream turbulence and pressure gradient on the laminar/turbulent transition. The intermittent feature of flow in the transition region is described by the algebraic relation for the intermittency coefficient and empirical relations for the onset and length of the transition region. The model was tested for flat-plate flows under various free-stream turbulence (ERCOFTAC test cases), and for transonic flow through a turbine blade cascade.
Vysokorychlostní aerodynamický výzkum patní lopatkové mříže
Luxa, Martin ; Synáč, J. ; Šafařík, Pavel ; Šimurda, David
The paper is concerned with results of high-speed aerodynamic research on a blade cascade. The blade cascade represents root section of the last stage rotor blades of large output steam turbine. basic aerodynamic characterisitcs of the blade cascade are represented together with flow field photographs in a range of transsonic velocities.

Interested in being notified about new results for this query?
Subscribe to the RSS feed.