Jiří Dobeš

Numerical modeling of unsteady flow in steam turbine stage

This work deals with numerical solution of unsteady flow in turbine stage. We use models of compressible single-phase flow of air and two-phase flow of wet steam. Presented numerical methods are based on different stator-rotor matching algorithms, as well as different numerical schemes. Numerical results achieved by both methods and flow models are discussed.

Numerical Simulation of Transonic Flow in Steam Turbine Cascades

This contribution presents numerical simulations and joined specific issues for several cases of 2D and 3D transonic flow in real-life steam turbine cascades.

Numerical Solution of Turbine Cascade Flow by Two Equations, EARSM and Bypass Transition Turbulence Models

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. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim)

Numerical Solution of Transonic and Supersonic 2D and 3D Fluid–Elastic Structure Interaction Problems

We solve the system of Euler or Navier-Stokes equations in conservative ALE formulation, possibly supplemented by a suitable turbulence model. The structural dynamics is described by the equations of anisotropic elastic continuum with large or small displacements. The problem is closed by suitable interface conditions. We present a cell centered finite volume method with linear least square reconstruction with nonlinear WENO type weights, a cell centered finite volume method with linear reconstruction and Barth’s limiter and a residual distribution scheme to solve the CFD sub-problem. To allow a large time step, all the considered methods use implicit time stepping formulated in dual time. The elastic problem and the mesh motion is solved by a simple finite element method. The whole problem is formulated in dual time and solved by a simple sub-iteration procedure. We present several numerical tests documenting the behavior of the methods. These include 2D transonic turbulent flow past a forced oscillatory pitching NACA0012 airfoil, 2D inviscid supersonic panel flutter and 3D inviscid flow past the elastic AGARD 445.6 wing.

Numerical Solution of 3D Flow Fields Utilized for Problems of Flow Through Transonic Stages

This contribution summarizes results of several numerical methods developed at our department. Presented methods are based on central Lax Wendroff type schemes and upwind schemes with Riemann solver. The results of 2D methods with different types of grid has been discussed for several typical axial and radial cascade geometries, comparisons of 3D results are presented for several geometries of blade row.