Heat Transfer Analysis Of A Rotating Ribbed Channel By Means Of Large Eddy Simulations

Abstract

The present work studies the three-dimensional flow field and heat transfer in a model of an internal cooling channel in rotation by means of Large Eddy Simulations (LES). The selected geometry corresponds to a section of an experimental facility documented in the open literature. The channel presents a low aspect ratio cross section, one ribbed wall and square ribs placed perpendicularly to the main flow direction. In order to reduce the computational cost, the length of the computational domain is equal to the rib pitch of the laboratory model, whereas periodic boundary conditions are provided at the inlet and outlet of the domain. The simulations are carried out under the same conditions as in the experiments, namely at a Reynolds number equal to 15,000 and a Rotation number equal to 0.3. The first objective of this work is to provide the three dimensional flow field that experiments were not able to retrieve, and to discuss its impact on the wall heat transfer. Moreover, the dimensionless mean temperature fields in static and rotating conditions are introduced. Secondly, this work aims to study the suitability of an open source Computational Fluid Dynamics (CFD) solver to investigate the heat transfer phenomena in turbine internal cooling. With the selected LES turbulence model and boundary conditions, the present simulations provide a good agreement with the detailed experimental data.