The contribution presents results of the numerical simulation of 2D compressible flow through the tip-section turbine blade cascade with a flat profile and the supersonic inlet. The simulation was carried out by the OpenFOAM code using the Favre-averaged Navier-Stokes equations completed by the two-equation SST turbulence model and the -Re  bypass transition model. Predictions carried out for nominal conditions were focused particularly on the relation between the inlet flow angle and the inlet Mach number. Further, the effect of the shock-wave/boundary layer interaction on the skin friction coefficient was investigated. Numerical results were compared with experimental data.

The contribution deals with the simulation of the laminar/turbulent transition on a rough wall. The algebraic transition model taking into account wall roughness according to Straka and Příhoda [8] was further extended for the effect of short rough strip near the leading edge. The proposed correlation was tested by means of incompressible flow over a flat plate covered by sand paper and around the NACA 0012 airfoil with a rough strip near the leading edge. The agreement with experiments is appropriate nevertheless the applicability of the correlation is limited due to the lack of relevant experimental results.

The work deals with numerical simulation of turbulent flow 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 fluctuations 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.

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.

This work deals with numerical solution of transonic flow in turbine cascades. We compare results achieved by SST, TNT and EARSM turbulence models and we also present results achieved by two equations turbulence model with an algebraic bypass transition model. Mathematical models and numerical methodsWe consider the conservative system of Favre averaged Navier-Stokes equations for compressible flow.Two types of two equation turbulence models have been used -TNT k − ω model of Kok and SST k − ω/k − model of Menter. We implemented also the explicit Reynolds stress model of Wallin [2] which uses proper explicit formulae to evaluate turbulent stress tensor components as a function of k, ω (computed by two equations turbulence model, e.g. TNT or SST) and other flow paramers. Next we consider a two equation SST turbulence model extended by an algebraic model of the bypass transition. It is based on the empirical relation for the intermittency coefficient γ ∈< 0, 1 > proposed by Narasimha, and proper algebraic relations for transition onset and lenght of transition region. The position of the transition onset is described by the Reynolds numberRe xt determined by means of the momentum Reynolds number Re θt = f (T u, λ t ), where T u is the free-stream turbulence level and λ t is the pressure gradient parameter. Both parameters are considered at the location of the transition onset. The length of the transition region is given by parameters describing the spot generation raten and spot propagation parameter σ.The problem is solved by several alternative implicit schemes based on the finite volume method in cell-centered formulation: Method 1. The method is based on AUSM scheme and linear interpolation with van Leer's limiter on multi-block structured grid. Some numerical resultsIn-house developed implicit methods differs in type of used grid, numerical flux, reconstruction on finite volume or limiter. They can be used with different turbulence models. This fact gives us opportunity to study numerically an influence of a numerical scheme, a grid topology, a turbulence model on the flow field in turbine cascade and especially on loss prediction. We present here numerical results for flow through SE1050 cascade at design conditions (inlet velocity angle 19.3deg and isoentropic outlet Mach number M 2is = 1.198. The first two results in Fig.1 shows isolines of Mach number achieved by method 1 and two diferent turbulence models -EARSM and SST. The right figure shows results achieved by method 3 on hybrid grid also with SST turbulence model but together with the algebraic model of boundary layer transition. We can observe similar shape of isolines and very good agreement of computed shock waves structure. Diferences between SST and EARSM models are more visible on isolines of kinetic turbulent energy k ploted in Fig.2. We can observe especialy much stronger production of k along relatively weak shock wave behind the trailing edge of profile in case of SST model. The influence of boundary layer transition model is shown in Fi...