Transition modelling with an algebraic equation of intermittency

Description

The research is on development of an algebraic model for laminar-turbulent boundary layer flow transition added to two-equation RANS turbulence models, with application to turbomachinery flows. The modelled phenomena are bypass transition in attached boundary layer state, transition by instability in boundary layer separated state and wake-induced transition in attached and separated boundary layer state. The algebraic model uses the intermittency concept. It modifies the production terms of the k-w RANS turbulence model by Wilcox. For attached flows, the model describes bypass transition by taking into account two main effects, which are damping of high-frequency disturbances by a laminar shear layer and breakdown of a near-wall laminar layer perturbed by streaks. For separated flow, the model describes instability and breakdown of a laminar free shear layer. Currently, the model ingredients for transition in separated state are further developed.

Publications

  • KUBACKI S., DICK E.: An algebraic model for bypass transition in turbomachinery boundary layer flows.   Int. J. of Heat and Fluid Flow, 58 (2016), 68-83.
  • KUBACKI S., DICK E.: An algebraic intermittency model for bypass, separation-induced and wake-induced transition.   Int. J. of Heat and Fluid Flow, 62 (2016), 344-361.
  • DICK E., KUBACKI S.: Transition models for turbomachinery boundary layer flows: a review. Int. J. of Turbomachinery Propulsion and Power, 2 (2017), 4/1-44.