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Effect of Various Boundary Conditions on the Supersonic Flow Through the Tip-Section Turbine Blade Cascade with a Flat Profile
Musil, Josef ; Příhoda, Jaromír ; Fürst, J.
The paper deals with the numerical simulation of 2D compressible flow though the tip-section turbine blade cascade with a flat profile. The OpenFOAM code was used for simulations based on the Favre-averaged Navier-Stokes equations completed by the two-equation SST turbulence model and the gama-Re_th transition model proposed by Langtry and Menter (2009). Calculations were carried out for two nominal regimes with the inlet Mach number M1 = 1.2 and isentropic outlet Mach numbers M2is = 1.7 and 1.9. Simulations of compressible flow with the supersonic inlet were focused on the relation between of the inlet Mach number and the inlet angle given by the unique incidence rule. Further, the effect of the inlet free-stream turbulence and of the outlet isentropic Mach number on the flow filed in the blade cascade was investigated. Numerical results were compared with results of optical and pressure measurements.
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Simulation of Transonic Flow Through a Mid-span Turbine Blade Cascade for Various Mach Numbers
Straka, P. ; Příhoda, Jaromír ; Fenderl, D.
The contribution deals with the numerical simulation of 2D transonic flow through a mid-span turbine blade cascade for several Mach numbers by means of the EARSM turbulence model of Hellsten (2004) connected with the algebraic bypass transition model of Straka and Příhoda (2014). Both models are implemented into an in-house numerical code based on the finite volume method. The gamma-transition model of Menter et al. (2015) with SST turbulence model accessible in the commercial code ANSYS Fluent was used for the comparison.
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Transition Modelling on Separated Flow in Turbine Cascade
Louda, Petr ; Příhoda, Jaromír ; Kozel, K.
The work deals with numerical simulation of turbulent ow through turbine cascade by RANS model with model of transition to turbulence. Performance of two transition models is compared. First one is gamma-zeta model based on transition criteria, second one algebraic transition model based on the concept of laminar uctuations energy (Kubacki, Dick 2016). The criterion for transition in separated state is re-formulated in order to remove stream-wise non-local formulation. The performance of the transition models is observed on the shock wave - boundary layer interaction on turbine blade.
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CFD Calculations in Turbomachinery and their Validation
Váchová, J. ; Louda, P. ; Příhoda, Jaromír ; Luxa, Martin ; Šimurda, David
Numerical data obtained by 2D compressible flow CFD simulation were validated by the comparison with experimental results. The investigation was made on the mid-section of the 48" long rotor blade and it was focused on the effect of shock-wave interactions with shear layers. This interaction results in the laminar/turbulent transition where separated flow occurs and it has impacts on flow structure and the blade cascade losses. Numerical simulations were carried out by two different codes: the commercial code NUMECA based on the gamma-Re transition model connected with the SST k-epsilon/k-omega turbulence model and in-house code of the Dept. of Technical mathematics, CTU Prague/ Institute of Thermodynamics in Prague. Simulations of the laminar and the fully turbulent flows were accomplished for comparison using the same numerical approach.
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