Turbulent Flows

The research in this area is mainly focused on the modeling and numerical simulation of turbulent channel flow, turbulent jet flow and turbulent reacting flow. The channel flow computations are essentially performed using a Reynolds Averaged Navier Stokes (RANS) formulation, which is solved numerically. In these RANS-type simulations a k-epsilon model is used as turbulence model which is occasionally modified to improve the predictions in particular flow configurations with strong streamline curvature, or, centrifugal acceleration due to rotation. The simulations of turbulent combustion apply the method of LES to non-premixed diffusion flames. There, the major challenge is to close the unresolved chemical source terms, which are highly non-linear Arrhenius-type expressions. Some further computational activities deal with turbulent external flows relevant in the aerodynamics of sports like ski jumping. In particular they consider the flow around a flat blunt body which is inclined with different angles against the direction of the main flow. Data obtained from in-house wind tunnel experiments are used to validate the numerical predictions especially for the lift and the drag forces acting on the body.