## Abstract

The goal of this work is to predict the boundary layer transition

induced by a separation bubble on the suction side of a turbine

blade of a linear turbine cascade using Large Eddy Simulation

(LES). The numerical simulations refer to the linear turbine

cascade T106D-EIZ tested at the Institute for Jet Propulsion of

the Bundeswehr University Munich (Germany). The blade pitch

was increased compared to the design point in order to have a

higher load and enhance the formation of a separation bubble at

the suction side of the blade. Different flow configurations were

tested and the transition of the boundary layer was evaluated.

For the numerical case, the operating condition with an inlet turbulence

below 1% was used. In the first part of this work, the

LES setup is discussed. A modified Smagorinsky subgrid-scale

model is used to reduce the turbulent viscosity in the region closest

to the wall. The computational grid is designed according

to the information coming from the Taylor and the Kolmogorov

length scales. These parameters are found from RANS k-omega

SST simulations. The fifth-order accurate WENO scheme was

used for the computation of the cell fluxes. In the second part of

the work, a comparison between the results of the LES simulations

and of the RANS k-omega SST simulations with the gamma-Re theta

transition model is done. Integral and statistical parameters of

the boundary layer from the simulations with the two models are

evaluated and compared. The ability of the LES and the RANS

models to predict the boundary layer evolution along the blade

profile and the point of separation will be discussed.

induced by a separation bubble on the suction side of a turbine

blade of a linear turbine cascade using Large Eddy Simulation

(LES). The numerical simulations refer to the linear turbine

cascade T106D-EIZ tested at the Institute for Jet Propulsion of

the Bundeswehr University Munich (Germany). The blade pitch

was increased compared to the design point in order to have a

higher load and enhance the formation of a separation bubble at

the suction side of the blade. Different flow configurations were

tested and the transition of the boundary layer was evaluated.

For the numerical case, the operating condition with an inlet turbulence

below 1% was used. In the first part of this work, the

LES setup is discussed. A modified Smagorinsky subgrid-scale

model is used to reduce the turbulent viscosity in the region closest

to the wall. The computational grid is designed according

to the information coming from the Taylor and the Kolmogorov

length scales. These parameters are found from RANS k-omega

SST simulations. The fifth-order accurate WENO scheme was

used for the computation of the cell fluxes. In the second part of

the work, a comparison between the results of the LES simulations

and of the RANS k-omega SST simulations with the gamma-Re theta

transition model is done. Integral and statistical parameters of

the boundary layer from the simulations with the two models are

evaluated and compared. The ability of the LES and the RANS

models to predict the boundary layer evolution along the blade

profile and the point of separation will be discussed.

Originalsprache | englisch |
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Publikationsstatus | Veröffentlicht - 2019 |

Veranstaltung | ASME Turbo Expo 2019: Turbomachinery Technical Conference & Exhibition - Phoenix, USA / Vereinigte Staaten Dauer: 17 Jun 2019 → 21 Jun 2019 |

### Konferenz

Konferenz | ASME Turbo Expo 2019 |
---|---|

Land | USA / Vereinigte Staaten |

Ort | Phoenix |

Zeitraum | 17/06/19 → 21/06/19 |

## Fields of Expertise

- Mobility & Production